Don't race exiting a sketch scene (#7128)

* Turn sketch exit execute into actor, no more racey exits

* Turn sketch exit execute into actor, no more racey exits

* Fix types

---------

Co-authored-by: Frank Noirot <frank@zoo.dev>

.github/ci-cd-scripts/upload-results.sh

@@ -6,6 +6,7 @@ if [ -z "${TAB_API_URL:-}" ] || [ -z "${TAB_API_KEY:-}" ]; then
 fi
 
 project="https://github.com/KittyCAD/modeling-app"
+suite="${CI_SUITE:-unit}"
 branch="${GITHUB_HEAD_REF:-${GITHUB_REF_NAME:-}}"
 commit="${CI_COMMIT_SHA:-${GITHUB_SHA:-}}"
 
@@ -13,6 +14,7 @@ echo "Uploading batch results"
 curl --silent --request POST \
   --header "X-API-Key: ${TAB_API_KEY}" \
   --form "project=${project}" \
+  --form "suite=${suite}" \
   --form "branch=${branch}" \
   --form "commit=${commit}" \
   --form "tests=@test-results/junit.xml" \

.github/workflows/cargo-test.yml

@@ -88,6 +88,7 @@ jobs:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
           RUST_BACKTRACE: full
+          RUST_MIN_STACK: 10485760000
       - name: Commit differences
         if: steps.path-changes.outputs.outside-kcl-samples == 'false' && steps.cargo-test-kcl-samples.outcome == 'failure'
         shell: bash
@@ -119,6 +120,7 @@ jobs:
           # Configure nextest when it's run by insta (via just).
           NEXTEST_PROFILE: ci
           RUST_BACKTRACE: full
+          RUST_MIN_STACK: 10485760000
       - name: Build and archive tests
         run: |
           cd rust
@@ -182,6 +184,7 @@ jobs:
         env:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
+          RUST_MIN_STACK: 10485760000
       - name: Upload results
         if: always()
         run: .github/ci-cd-scripts/upload-results.sh
@@ -190,6 +193,7 @@ jobs:
           TAB_API_KEY: ${{ secrets.TAB_API_KEY }}
           CI_COMMIT_SHA: ${{ github.event.pull_request.head.sha }}
           CI_PR_NUMBER: ${{ github.event.pull_request.number }}
+          CI_SUITE: unit:kcl
   run-internal-kcl-samples:
     name: cargo test (internal-kcl-samples)
     runs-on:
@@ -238,6 +242,7 @@ jobs:
           KITTYCAD_API_TOKEN: ${{secrets.KITTYCAD_API_TOKEN_DEV}}
           ZOO_HOST: https://api.dev.zoo.dev
           MODELING_APP_INTERNAL_SAMPLES_SECRET: ${{secrets.MODELING_APP_INTERNAL_SAMPLES_SECRET}}
+          RUST_MIN_STACK: 10485760000
   run-wasm-tests:
     name: Run wasm tests
     strategy:

.github/workflows/e2e-tests.yml

@@ -143,7 +143,7 @@ jobs:
       - name: Install browsers
         run: npm run playwright install --with-deps
 
-      - name: Capture snapshots
+      - name: Test snapshots
         uses: nick-fields/retry@v3.0.2
         with:
           shell: bash
@@ -156,6 +156,19 @@ jobs:
           TAB_API_KEY: ${{ secrets.TAB_API_KEY }}
           CI_COMMIT_SHA: ${{ github.event.pull_request.head.sha }}
           CI_PR_NUMBER: ${{ github.event.pull_request.number }}
+          CI_SUITE: snapshots
+          TARGET: web
+
+      - name: Update snapshots
+        if: always()
+        run: npm run test:snapshots -- --last-failed --update-snapshots
+        env:
+          token: ${{ secrets.KITTYCAD_API_TOKEN_DEV }}
+          TAB_API_URL: ${{ secrets.TAB_API_URL }}
+          TAB_API_KEY: ${{ secrets.TAB_API_KEY }}
+          CI_COMMIT_SHA: ${{ github.event.pull_request.head.sha }}
+          CI_PR_NUMBER: ${{ github.event.pull_request.number }}
+          CI_SUITE: snapshots
           TARGET: web
 
       - uses: actions/upload-artifact@v4
@@ -173,7 +186,7 @@ jobs:
         id: git-check
         run: |
             git add e2e/playwright/snapshot-tests.spec.ts-snapshots e2e/playwright/snapshots
-            if git status | grep -q "Changes to be committed"
+            if git status | grep --quiet "Changes to be committed"
             then echo "modified=true" >> $GITHUB_OUTPUT
             else echo "modified=false" >> $GITHUB_OUTPUT
             fi

docs/kcl-lang/index.md

@@ -4,7 +4,7 @@ excerpt: "Documentation of the KCL language for the Zoo Design Studio."
 layout: manual
 ---
 
-This is a reference for KCL. If you are learning KCL, you may prefer the [guide]() which explains
+This is a reference for KCL. If you are learning KCL, you may prefer the [guide](https://zoo.dev/docs/kcl-book/intro.html) which explains
 things in a more tutorial fashion. See also our documentation of the [standard library](/docs/kcl-std).
 
 ## Topics

docs/kcl-lang/modules.md

@@ -27,9 +27,6 @@ import increment from "util.kcl"
 answer = increment(41)
 ```
 
-Imported files _must_ be in the same project so that units are uniform across
-modules. This means that it must be in the same directory.
-
 Import statements must be at the top-level of a file. It is not allowed to have
 an `import` statement inside a function or in the body of an if‑else.
 
@@ -58,6 +55,9 @@ Imported symbols can be renamed for convenience or to avoid name collisions.
 import increment as inc, decrement as dec from "util.kcl"
 ```
 
+You can import files from the current directory or from subdirectories, but if importing from a
+subdirectory you can only import `main.kcl`.
+
 ---
 
 ## Functions vs `clone`
@@ -229,6 +229,19 @@ The final statement is what's important because it's the return value of the
 entire module. The module is expected to return a single object that can be used
 as a variable by the file that imports it.
 
+The name of the file or subdirectory is used as the name of the variable within the importing program.
+If you want to use a different name, you can do so by using the `as` keyword:
+
+```kcl,norun
+import "cube.kcl"                // Introduces a new variable called `cube`.
+import "cube.kcl" as block       // Introduces a new variable called `block`.
+import "cube/main.kcl"           // Introduces a new variable called `cube`.
+import "cube/main.kcl" as block  // Introduces a new variable called `block`.
+```
+
+If the filename includes hyphens (`-`) or starts with an underscore (`_`), then you must specify a
+variable name.
+
 ---
 
 ## Multiple instances of the same import

docs/kcl-std/functions/std-sketch-circle.md

@@ -11,7 +11,8 @@ layout: manual
 circle(
   @sketch_or_surface: Sketch | Plane | Face,
   center: Point2d,
-  radius: number(Length),
+  radius?: number(Length),
+  diameter?: number(Length),
   tag?: tag,
 ): Sketch
 ```
@@ -25,7 +26,8 @@ the provided (x, y) origin point.
 |----------|------|-------------|----------|
 | `sketch_or_surface` | [`Sketch`](/docs/kcl-std/types/std-types-Sketch) or [`Plane`](/docs/kcl-std/types/std-types-Plane) or [`Face`](/docs/kcl-std/types/std-types-Face) | Sketch to extend, or plane or surface to sketch on. | Yes |
 | `center` | [`Point2d`](/docs/kcl-std/types/std-types-Point2d) | The center of the circle. | Yes |
-| `radius` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The radius of the circle. | Yes |
+| `radius` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The radius of the circle. Incompatible with `diameter`. | No |
+| `diameter` | [`number(Length)`](/docs/kcl-std/types/std-types-number) | The diameter of the circle. Incompatible with `radius`. | No |
 | [`tag`](/docs/kcl-std/types/std-types-tag) | [`tag`](/docs/kcl-std/types/std-types-tag) | Create a new tag which refers to this circle. | No |
 
 ### Returns
@@ -51,7 +53,7 @@ exampleSketch = startSketchOn(XZ)
   |> line(end = [0, 30])
   |> line(end = [-30, 0])
   |> close()
-  |> subtract2d(tool = circle(center = [0, 15], radius = 5))
+  |> subtract2d(tool = circle(center = [0, 15], diameter = 10))
 
 example = extrude(exampleSketch, length = 5)
 ```

docs/kcl-std/functions/std-sketch-patternTransform2d.md

@@ -1,19 +1,19 @@
 ---
 title: "patternTransform2d"
 subtitle: "Function in std::sketch"
-excerpt: "Just like patternTransform, but works on 2D sketches not 3D solids."
+excerpt: "Just like `patternTransform`, but works on 2D sketches not 3D solids."
 layout: manual
 ---
 
-Just like patternTransform, but works on 2D sketches not 3D solids.
+Just like `patternTransform`, but works on 2D sketches not 3D solids.
 
 ```kcl
 patternTransform2d(
-  @sketches: [Sketch],
+  @sketches: [Sketch; 1+],
-  instances: number,
+  instances: number(_),
-  transform: FunctionSource,
+  transform: fn(number(_)): { },
-  useOriginal?: bool,
+  useOriginal?: boolean,
-): [Sketch]
+): [Sketch; 1+]
 ```
 
 
@@ -22,14 +22,14 @@ patternTransform2d(
 
 | Name | Type | Description | Required |
 |----------|------|-------------|----------|
-| `sketches` | [`[Sketch]`](/docs/kcl-std/types/std-types-Sketch) | The sketch(es) to duplicate | Yes |
+| `sketches` | [`[Sketch; 1+]`](/docs/kcl-std/types/std-types-Sketch) | The sketch(es) to duplicate. | Yes |
-| `instances` | [`number`](/docs/kcl-std/types/std-types-number) | The number of total instances. Must be greater than or equal to 1. This includes the original entity. For example, if instances is 2, there will be two copies -- the original, and one new copy. If instances is 1, this has no effect. | Yes |
+| `instances` | [`number(_)`](/docs/kcl-std/types/std-types-number) | The number of total instances. Must be greater than or equal to 1. This includes the original entity. For example, if instances is 2, there will be two copies -- the original, and one new copy. If instances is 1, this has no effect. | Yes |
-| `transform` | `FunctionSource` | How each replica should be transformed. The transform function takes a single parameter: an integer representing which number replication the transform is for. E.g. the first replica to be transformed will be passed the argument `1`. This simplifies your math: the transform function can rely on id `0` being the original instance passed into the `patternTransform`. See the examples. | Yes |
+| `transform` | [`fn(number(_)): { }`](/docs/kcl-std/types/std-types-fn) | How each replica should be transformed. The transform function takes a single parameter: an integer representing which number replication the transform is for. E.g. the first replica to be transformed will be passed the argument `1`. This simplifies your math: the transform function can rely on id `0` being the original instance passed into the `patternTransform`. See the examples. | Yes |
-| `useOriginal` | [`bool`](/docs/kcl-std/types/std-types-bool) | If the target was sketched on an extrusion, setting this will use the original sketch as the target, not the entire joined solid. Defaults to false. | No |
+| `useOriginal` | `boolean` | If the target was sketched on an extrusion, setting this will use the original sketch as the target, not the entire joined solid. | No |
 
 ### Returns
 
-[`[Sketch]`](/docs/kcl-std/types/std-types-Sketch)
+[`[Sketch; 1+]`](/docs/kcl-std/types/std-types-Sketch)
 
 
 ### Examples

docs/kcl-std/index.md

@@ -65,7 +65,7 @@ layout: manual
   * [`line`](/docs/kcl-std/line)
   * [`loft`](/docs/kcl-std/loft)
   * [`patternCircular2d`](/docs/kcl-std/patternCircular2d)
-  * [`patternTransform2d`](/docs/kcl-std/patternTransform2d)
+  * [`patternTransform2d`](/docs/kcl-std/functions/std-sketch-patternTransform2d)
   * [`polygon`](/docs/kcl-std/polygon)
   * [`profileStart`](/docs/kcl-std/profileStart)
   * [`profileStartX`](/docs/kcl-std/profileStartX)
@@ -94,7 +94,7 @@ layout: manual
   * [`intersect`](/docs/kcl-std/intersect)
   * [`patternCircular3d`](/docs/kcl-std/patternCircular3d)
   * [`patternLinear3d`](/docs/kcl-std/patternLinear3d)
-  * [`patternTransform`](/docs/kcl-std/patternTransform)
+  * [`patternTransform`](/docs/kcl-std/functions/std-solid-patternTransform)
   * [`shell`](/docs/kcl-std/functions/std-solid-shell)
   * [`subtract`](/docs/kcl-std/subtract)
   * [`union`](/docs/kcl-std/union)

docs/kcl-std/modules/std-sketch.md

@@ -30,7 +30,7 @@ This module contains functions for creating and manipulating sketches, and makin
 * [`line`](/docs/kcl-std/line)
 * [`loft`](/docs/kcl-std/loft)
 * [`patternCircular2d`](/docs/kcl-std/patternCircular2d)
-* [`patternTransform2d`](/docs/kcl-std/patternTransform2d)
+* [`patternTransform2d`](/docs/kcl-std/functions/std-sketch-patternTransform2d)
 * [`polygon`](/docs/kcl-std/polygon)
 * [`profileStart`](/docs/kcl-std/profileStart)
 * [`profileStartX`](/docs/kcl-std/profileStartX)

docs/kcl-std/modules/std-solid.md

@@ -18,7 +18,7 @@ This module contains functions for modifying solids, e.g., by adding a fillet or
 * [`intersect`](/docs/kcl-std/intersect)
 * [`patternCircular3d`](/docs/kcl-std/patternCircular3d)
 * [`patternLinear3d`](/docs/kcl-std/patternLinear3d)
-* [`patternTransform`](/docs/kcl-std/patternTransform)
+* [`patternTransform`](/docs/kcl-std/functions/std-solid-patternTransform)
 * [`shell`](/docs/kcl-std/functions/std-solid-shell)
 * [`subtract`](/docs/kcl-std/subtract)
 * [`union`](/docs/kcl-std/union)

docs/kcl-std/modules/std.md

@@ -11,7 +11,7 @@ Contains frequently used constants, functions for interacting with the KittyCAD
 
 The standard library is organised into modules (listed below), but most things are always available in KCL programs. 
 
-You might also want the [KCL language reference](/docs/kcl-lang) or the [KCL guide](). 
+You might also want the [KCL language reference](/docs/kcl-lang) or the [KCL guide](https://zoo.dev/docs/kcl-book/intro.html). 
 
 ## Modules
 

e2e/playwright/code-pane-and-errors.spec.ts

@@ -235,6 +235,48 @@ extrude001 = extrude(sketch001, length = 5)`
         .first()
     ).toBeVisible()
   })
+
+  test('KCL errors with functions show hints for the entire backtrace', async ({
+    page,
+    homePage,
+    scene,
+    cmdBar,
+    editor,
+    toolbar,
+  }) => {
+    await homePage.goToModelingScene()
+    await scene.settled(cmdBar)
+
+    const code = `fn check(@x) {
+  return assert(x, isGreaterThan = 0)
+}
+
+fn middle(@x) {
+  return check(x)
+}
+
+middle(1)
+middle(0)
+`
+    await test.step('Set the code with a KCL error', async () => {
+      await toolbar.openPane('code')
+      await editor.replaceCode('', code)
+    })
+    // This shows all the diagnostics in a way that doesn't require the mouse
+    // pointer hovering over a coordinate, which would be brittle.
+    await test.step('Open CodeMirror diagnostics list', async () => {
+      // Ensure keyboard focus is in the editor.
+      await page.getByText('fn check(').click()
+      await page.keyboard.press('ControlOrMeta+Shift+M')
+    })
+    await expect(
+      page.getByText(`assert failed: Expected 0 to be greater than 0 but it wasn't
+check()
+middle()`)
+    ).toBeVisible()
+    // There should be one hint inside middle() and one at the top level.
+    await expect(page.getByText('Part of the error backtrace')).toHaveCount(2)
+  })
 })
 
 test(

e2e/playwright/command-bar-tests.spec.ts

@@ -45,15 +45,16 @@ test.describe('Command bar tests', () => {
     await cmdBar.expectState({
       stage: 'arguments',
       commandName: 'Extrude',
-      currentArgKey: 'length',
+      currentArgKey: 'sketches',
-      currentArgValue: '5',
+      currentArgValue: '',
       headerArguments: {
-        Profiles: '1 profile',
+        Profiles: '',
         Length: '',
       },
-      highlightedHeaderArg: 'length',
+      highlightedHeaderArg: 'Profiles',
     })
     await cmdBar.progressCmdBar()
+    await cmdBar.progressCmdBar()
     await cmdBar.expectState({
       stage: 'review',
       commandName: 'Extrude',
@@ -684,4 +685,33 @@ c = 3 + a`
       highlightedHeaderArg: 'value',
     })
   })
+
+  test('Text-to-CAD command can be closed with escape while in prompt', async ({
+    page,
+    homePage,
+    cmdBar,
+  }) => {
+    await homePage.expectState({
+      projectCards: [],
+      sortBy: 'last-modified-desc',
+    })
+    await homePage.textToCadBtn.click()
+    await cmdBar.expectState({
+      stage: 'arguments',
+      commandName: 'Text-to-CAD Create',
+      currentArgKey: 'prompt',
+      currentArgValue: '',
+      headerArguments: {
+        Method: 'New project',
+        NewProjectName: 'untitled',
+        Prompt: '',
+      },
+      highlightedHeaderArg: 'prompt',
+    })
+    await page.keyboard.press('Escape')
+    await cmdBar.toBeClosed()
+    await cmdBar.expectState({
+      stage: 'commandBarClosed',
+    })
+  })
 })

e2e/playwright/editor-tests.spec.ts

@@ -1134,6 +1134,7 @@ sketch001 = startSketchOn(XZ)
     // Wait for the selection to register (TODO: we need a definitive way to wait for this)
     await page.waitForTimeout(200)
     await toolbar.extrudeButton.click()
+    await cmdBar.progressCmdBar()
     await cmdBar.expectState({
       stage: 'arguments',
       currentArgKey: 'length',
@@ -1355,9 +1356,7 @@ sketch001 = startSketchOn(XZ)
       const u = await getUtils(page)
       const projectLink = page.getByRole('link', { name: 'cube' })
       const gizmo = page.locator('[aria-label*=gizmo]')
-      const resetCameraButton = page.getByRole('button', {
+      const resetCameraButton = page.getByRole('button', { name: 'Reset view' })
-        name: 'Reset view',
-      })
       const locationToHaveColor = async (
         position: { x: number; y: number },
         color: [number, number, number]

e2e/playwright/file-tree.spec.ts

@@ -238,6 +238,26 @@ test.describe('when using the file tree to', () => {
     }
   )
 
+  test(
+    `create new folders and that doesn't trigger a navigation`,
+    { tag: ['@electron', '@macos', '@windows'] },
+    async ({ page, homePage, scene, toolbar, cmdBar }) => {
+      await homePage.goToModelingScene()
+      await scene.settled(cmdBar)
+      await toolbar.openPane('files')
+      const { createNewFolder } = await getUtils(page, test)
+
+      await createNewFolder('folder')
+
+      await createNewFolder('folder.kcl')
+
+      await test.step(`Postcondition: folders are created and we didn't navigate`, async () => {
+        await toolbar.expectFileTreeState(['folder', 'folder.kcl', 'main.kcl'])
+        await expect(toolbar.fileName).toHaveText('main.kcl')
+      })
+    }
+  )
+
   test(
     'deleting all files recreates a default main.kcl with no code',
     { tag: '@electron' },

e2e/playwright/fixtures/cmdBarFixture.ts

@@ -105,14 +105,19 @@ export class CmdBarFixture {
   expectState = async (expected: CmdBarSerialised) => {
     return expect.poll(() => this._serialiseCmdBar()).toEqual(expected)
   }
-  /** The method will use buttons OR press enter randomly to progress the cmdbar,
+  /**
-   * this could have unexpected results depending on what's focused
+   * This method is used to progress the command bar to the next step, defaulting to clicking the next button.
-   *
+   * Optionally, with the `shouldUseKeyboard` parameter, it will hit `Enter` to progress.
-   * TODO: This method assumes the user has a valid input to the current stage,
+   * * TODO: This method assumes the user has a valid input to the current stage,
    * and assumes we are past the `pickCommand` step.
    */
-  progressCmdBar = async (shouldFuzzProgressMethod = true) => {
+  progressCmdBar = async (shouldUseKeyboard = false) => {
     await this.page.waitForTimeout(2000)
+    if (shouldUseKeyboard) {
+      await this.page.keyboard.press('Enter')
+      return
+    }
+
     const arrowButton = this.page.getByRole('button', {
       name: 'arrow right Continue',
     })
@@ -308,6 +313,11 @@ export class CmdBarFixture {
     await expect(this.cmdBarElement).toBeVisible({ timeout: 10_000 })
   }
 
+  async toBeClosed() {
+    // Check that the command bar is closed
+    await expect(this.cmdBarElement).not.toBeVisible({ timeout: 10_000 })
+  }
+
   async expectArgValue(value: string) {
     // Check the placeholder project name exists
     const actualArgument = await this.cmdBarElement

e2e/playwright/fixtures/homePageFixture.ts

@@ -26,6 +26,7 @@ export class HomePageFixture {
   sortByNameBtn!: Locator
   appHeader!: Locator
   tutorialBtn!: Locator
+  textToCadBtn!: Locator
 
   constructor(page: Page) {
     this.page = page
@@ -47,6 +48,7 @@ export class HomePageFixture {
     this.sortByNameBtn = this.page.getByTestId('home-sort-by-name')
     this.appHeader = this.page.getByTestId('app-header')
     this.tutorialBtn = this.page.getByTestId('home-tutorial-button')
+    this.textToCadBtn = this.page.getByTestId('home-text-to-cad')
   }
 
   private _serialiseSortBy = async (): Promise<

e2e/playwright/lib/api-reporter.ts

@@ -61,6 +61,7 @@ class MyAPIReporter implements Reporter {
     const payload = {
       // Required information
       project: 'https://github.com/KittyCAD/modeling-app',
+      suite: process.env.CI_SUITE || 'e2e',
       branch: process.env.GITHUB_HEAD_REF || process.env.GITHUB_REF_NAME || '',
       commit: process.env.CI_COMMIT_SHA || process.env.GITHUB_SHA || '',
       test: test.titlePath().slice(2).join(' › '),

e2e/playwright/point-click-assemblies.spec.ts

@@ -70,22 +70,28 @@ test.describe('Point-and-click assemblies tests', () => {
       await test.step('Setup parts and expect empty assembly scene', async () => {
         const projectName = 'assembly'
         await context.folderSetupFn(async (dir) => {
-          const bracketDir = path.join(dir, projectName)
+          const projDir = path.join(dir, projectName)
-          await fsp.mkdir(bracketDir, { recursive: true })
+          const nestedProjDir = path.join(dir, projectName, 'nested', 'twice')
+          await fsp.mkdir(projDir, { recursive: true })
+          await fsp.mkdir(nestedProjDir, { recursive: true })
           await Promise.all([
             fsp.copyFile(
               executorInputPath('cylinder.kcl'),
-              path.join(bracketDir, 'cylinder.kcl')
+              path.join(projDir, 'cylinder.kcl')
+            ),
+            fsp.copyFile(
+              executorInputPath('cylinder.kcl'),
+              path.join(nestedProjDir, 'main.kcl')
             ),
             fsp.copyFile(
               executorInputPath('e2e-can-sketch-on-chamfer.kcl'),
-              path.join(bracketDir, 'bracket.kcl')
+              path.join(projDir, 'bracket.kcl')
             ),
             fsp.copyFile(
               testsInputPath('cube.step'),
-              path.join(bracketDir, 'cube.step')
+              path.join(projDir, 'cube.step')
             ),
-            fsp.writeFile(path.join(bracketDir, 'main.kcl'), ''),
+            fsp.writeFile(path.join(projDir, 'main.kcl'), ''),
           ])
         })
         await page.setBodyDimensions({ width: 1000, height: 500 })
@@ -167,6 +173,25 @@ test.describe('Point-and-click assemblies tests', () => {
         await expect(
           page.getByText('This file is already imported')
         ).toBeVisible()
+        await cmdBar.closeCmdBar()
+      })
+
+      await test.step('Insert a nested kcl part', async () => {
+        await insertPartIntoAssembly(
+          'nested/twice/main.kcl',
+          'main',
+          toolbar,
+          cmdBar,
+          page
+        )
+        await toolbar.openPane('code')
+        await page.waitForTimeout(10000)
+        await editor.expectEditor.toContain(
+          `
+          import "nested/twice/main.kcl" as main 
+          `,
+          { shouldNormalise: true }
+        )
       })
     }
   )

e2e/playwright/point-click.spec.ts

@@ -74,6 +74,15 @@ test.describe('Point-and-click tests', () => {
 
     await test.step('do extrude flow and check extrude code is added to editor', async () => {
       await toolbar.extrudeButton.click()
+      await cmdBar.expectState({
+        stage: 'arguments',
+        currentArgKey: 'sketches',
+        currentArgValue: '',
+        headerArguments: { Profiles: '', Length: '' },
+        highlightedHeaderArg: 'Profiles',
+        commandName: 'Extrude',
+      })
+      await cmdBar.progressCmdBar()
       await cmdBar.expectState({
         stage: 'arguments',
         currentArgKey: 'length',
@@ -1645,6 +1654,15 @@ sketch002 = startSketchOn(plane001)
 
         await test.step(`Go through the command bar flow with preselected sketches`, async () => {
           await toolbar.loftButton.click()
+          await cmdBar.expectState({
+            stage: 'arguments',
+            currentArgKey: 'sketches',
+            currentArgValue: '',
+            headerArguments: { Profiles: '' },
+            highlightedHeaderArg: 'Profiles',
+            commandName: 'Loft',
+          })
+          await cmdBar.progressCmdBar()
           await cmdBar.expectState({
             stage: 'review',
             headerArguments: { Profiles: '2 profiles' },
@@ -1855,7 +1873,11 @@ sketch002 = startSketchOn(XZ)
           },
           stage: 'review',
         })
-        await cmdBar.progressCmdBar()
+        // Confirm we can submit from the review step with just `Enter`
+        await cmdBar.progressCmdBar(true)
+        await cmdBar.expectState({
+          stage: 'commandBarClosed',
+        })
       })
 
       await test.step(`Confirm code is added to the editor, scene has changed`, async () => {
@@ -1995,7 +2017,7 @@ profile001 = ${circleCode}`
         },
         stage: 'review',
       })
-      await cmdBar.progressCmdBar()
+      await cmdBar.progressCmdBar(true)
       await editor.expectEditor.toContain(sweepDeclaration)
     })
 
@@ -2088,6 +2110,18 @@ extrude001 = extrude(sketch001, length = -12)
     await test.step(`Apply fillet to the preselected edge`, async () => {
       await page.waitForTimeout(100)
       await toolbar.filletButton.click()
+      await cmdBar.expectState({
+        commandName: 'Fillet',
+        highlightedHeaderArg: 'selection',
+        currentArgKey: 'selection',
+        currentArgValue: '',
+        headerArguments: {
+          Selection: '',
+          Radius: '',
+        },
+        stage: 'arguments',
+      })
+      await cmdBar.progressCmdBar()
       await cmdBar.expectState({
         commandName: 'Fillet',
         highlightedHeaderArg: 'radius',
@@ -2617,6 +2651,18 @@ extrude001 = extrude(profile001, length = 5)
       await test.step(`Apply fillet`, async () => {
         await page.waitForTimeout(100)
         await toolbar.filletButton.click()
+        await cmdBar.expectState({
+          commandName: 'Fillet',
+          highlightedHeaderArg: 'selection',
+          currentArgKey: 'selection',
+          currentArgValue: '',
+          headerArguments: {
+            Selection: '',
+            Radius: '',
+          },
+          stage: 'arguments',
+        })
+        await cmdBar.progressCmdBar()
         await cmdBar.expectState({
           commandName: 'Fillet',
           highlightedHeaderArg: 'radius',
@@ -2722,6 +2768,19 @@ extrude001 = extrude(sketch001, length = -12)
     await test.step(`Apply chamfer to the preselected edge`, async () => {
       await page.waitForTimeout(100)
       await toolbar.chamferButton.click()
+      await cmdBar.expectState({
+        commandName: 'Chamfer',
+        highlightedHeaderArg: 'selection',
+        currentArgKey: 'selection',
+        currentArgValue: '',
+        headerArguments: {
+          Selection: '',
+          Length: '',
+        },
+        stage: 'arguments',
+      })
+      await cmdBar.progressCmdBar()
+      await page.waitForTimeout(1000)
       await cmdBar.expectState({
         commandName: 'Chamfer',
         highlightedHeaderArg: 'length',
@@ -3205,6 +3264,8 @@ extrude001 = extrude(sketch001, length = 30)
         await test.step(`Go through the command bar flow with a preselected face (cap)`, async () => {
           await toolbar.shellButton.click()
           await cmdBar.progressCmdBar()
+          await page.waitForTimeout(500)
+          await cmdBar.progressCmdBar()
           await cmdBar.expectState({
             stage: 'review',
             headerArguments: {
@@ -3638,13 +3699,12 @@ tag=$rectangleSegmentC002,
       // revolve
       await editor.scrollToText(codeToSelection)
       await page.getByText(codeToSelection).click()
-      // Wait for the selection to register (TODO: we need a definitive way to wait for this)
-      await page.waitForTimeout(200)
       await toolbar.revolveButton.click()
       await cmdBar.progressCmdBar()
       await cmdBar.progressCmdBar()
       await cmdBar.progressCmdBar()
       await cmdBar.progressCmdBar()
+      await cmdBar.progressCmdBar()
 
       const newCodeToFind = `revolve001 = revolve(sketch002, angle = 360, axis = X)`
       expect(editor.expectEditor.toContain(newCodeToFind)).toBeTruthy()
@@ -4573,6 +4633,18 @@ path001 = startProfile(sketch001, at = [0, 0])
 
     await test.step('Go through command bar flow', async () => {
       await toolbar.extrudeButton.click()
+      await cmdBar.expectState({
+        stage: 'arguments',
+        currentArgKey: 'sketches',
+        currentArgValue: '',
+        headerArguments: {
+          Profiles: '',
+          Length: '',
+        },
+        highlightedHeaderArg: 'Profiles',
+        commandName: 'Extrude',
+      })
+      await cmdBar.progressCmdBar()
       await cmdBar.expectState({
         stage: 'arguments',
         currentArgKey: 'length',
@@ -4655,6 +4727,19 @@ path001 = startProfile(sketch001, at = [0, 0])
 
     await test.step('Go through command bar flow', async () => {
       await toolbar.sweepButton.click()
+      await cmdBar.expectState({
+        stage: 'arguments',
+        currentArgKey: 'sketches',
+        currentArgValue: '',
+        headerArguments: {
+          Profiles: '',
+          Path: '',
+          Sectional: '',
+        },
+        highlightedHeaderArg: 'Profiles',
+        commandName: 'Sweep',
+      })
+      await cmdBar.progressCmdBar()
       await cmdBar.expectState({
         stage: 'arguments',
         currentArgKey: 'path',
@@ -4739,6 +4824,19 @@ path001 = startProfile(sketch001, at = [0, 0])
     await test.step('Go through command bar flow', async () => {
       await toolbar.closePane('code')
       await toolbar.revolveButton.click()
+      await cmdBar.expectState({
+        stage: 'arguments',
+        currentArgKey: 'sketches',
+        currentArgValue: '',
+        headerArguments: {
+          Profiles: '',
+          AxisOrEdge: '',
+          Angle: '',
+        },
+        highlightedHeaderArg: 'Profiles',
+        commandName: 'Revolve',
+      })
+      await cmdBar.progressCmdBar()
       await cmdBar.expectState({
         stage: 'arguments',
         currentArgKey: 'axisOrEdge',

e2e/playwright/projects.spec.ts

@@ -11,6 +11,7 @@ import {
   getPlaywrightDownloadDir,
   getUtils,
   isOutOfViewInScrollContainer,
+  runningOnWindows,
 } from '@e2e/playwright/test-utils'
 import { expect, test } from '@e2e/playwright/zoo-test'
 
@@ -1979,7 +1980,6 @@ test(
   }
 )
 
-// Flaky
 test(
   'Original project name persist after onboarding',
   { tag: '@electron' },
@@ -2064,3 +2064,55 @@ test(
     })
   }
 )
+
+test(
+  'import from nested directory',
+  { tag: ['@electron', '@windows', '@macos'] },
+  async ({ scene, cmdBar, context, page }) => {
+    await context.folderSetupFn(async (dir) => {
+      const bracketDir = path.join(dir, 'bracket')
+      await fsp.mkdir(bracketDir, { recursive: true })
+      const nestedDir = path.join(bracketDir, 'nested')
+      await fsp.mkdir(nestedDir, { recursive: true })
+
+      await fsp.copyFile(
+        executorInputPath('cylinder-inches.kcl'),
+        path.join(nestedDir, 'main.kcl')
+      )
+      await fsp.writeFile(
+        path.join(bracketDir, 'main.kcl'),
+        runningOnWindows()
+          ? `import 'nested\\main.kcl' as thing\n\nthing`
+          : `import 'nested/main.kcl' as thing\n\nthing`
+      )
+    })
+
+    await page.setBodyDimensions({ width: 1200, height: 500 })
+    const u = await getUtils(page)
+
+    const pointOnModel = { x: 630, y: 280 }
+
+    await test.step('Opening the bracket project should load the stream', async () => {
+      // expect to see the text bracket
+      await expect(page.getByText('bracket')).toBeVisible()
+
+      await page.getByText('bracket').click()
+
+      await scene.settled(cmdBar)
+
+      await expect(
+        page.getByRole('button', { name: 'Start Sketch' })
+      ).toBeEnabled({
+        timeout: 20_000,
+      })
+
+      // gray at this pixel means the stream has loaded in the most
+      // user way we can verify it (pixel color)
+      await expect
+        .poll(() => u.getGreatestPixDiff(pointOnModel, [125, 125, 125]), {
+          timeout: 10_000,
+        })
+        .toBeLessThan(15)
+    })
+  }
+)

e2e/playwright/sketch-tests.spec.ts

@@ -1016,6 +1016,7 @@ profile001 = startProfile(sketch001, at = [${roundOff(scale * 69.6)}, ${roundOff
 
     // sketch selection should already have been made.
     // otherwise the cmdbar would be waiting for a selection.
+    await cmdBar.progressCmdBar()
     await cmdBar.expectState({
       stage: 'arguments',
       currentArgKey: 'length',

e2e/playwright/test-utils.ts

@@ -557,6 +557,14 @@ export async function getUtils(page: Page, test_?: typeof test) {
       })
     },
 
+    createNewFolder: async (name: string) => {
+      return test?.step(`Create a folder named ${name}`, async () => {
+        await page.getByTestId('create-folder-button').click()
+        await page.getByTestId('tree-input-field').fill(name)
+        await page.keyboard.press('Enter')
+      })
+    },
+
     cloneFile: async (name: string) => {
       return test?.step(`Cloning file '${name}'`, async () => {
         await page

e2e/playwright/testing-samples-loading.spec.ts

@@ -103,6 +103,8 @@ test.describe('Testing loading external models', () => {
         file: 'ball-bearing' + FILE_EXT,
         title: 'Ball Bearing',
         file1: 'ball-bearing-1' + FILE_EXT,
+        folderName: 'ball-bearing',
+        folderName1: 'ball-bearing-1',
       }
       const projectCard = page.getByRole('link', { name: 'bracket' })
       const overwriteWarning = page.getByText(
@@ -154,8 +156,10 @@ test.describe('Testing loading external models', () => {
 
       await test.step(`Ensure we made and opened a new file`, async () => {
         await editor.expectEditor.toContain('// ' + sampleOne.title)
-        await expect(newlyCreatedFile(sampleOne.file)).toBeVisible()
+        await expect(
-        await expect(projectMenuButton).toContainText(sampleOne.file)
+          page.getByTestId('file-tree-item').getByText(sampleOne.folderName)
+        ).toBeVisible()
+        await expect(projectMenuButton).toContainText('main.kcl')
       })
 
       await test.step(`Load a KCL sample with the command palette`, async () => {
@@ -169,8 +173,10 @@ test.describe('Testing loading external models', () => {
 
       await test.step(`Ensure we made and opened a new file with a unique name`, async () => {
         await editor.expectEditor.toContain('// ' + sampleOne.title)
-        await expect(newlyCreatedFile(sampleOne.file1)).toBeVisible()
+        await expect(
-        await expect(projectMenuButton).toContainText(sampleOne.file1)
+          page.getByTestId('file-tree-item').getByText(sampleOne.folderName1)
+        ).toBeVisible()
+        await expect(projectMenuButton).toContainText('main.kcl')
       })
     }
   )

e2e/playwright/text-to-cad-tests.spec.ts

@@ -984,12 +984,12 @@ test.describe('Mocked Text-to-CAD API tests', { tag: ['@skipWin'] }, () => {
       )
       await expect(page.getByTestId('app-header-file-name')).toBeVisible()
       await expect(page.getByTestId('app-header-file-name')).toContainText(
-        '2x2x2-cube.kcl'
+        'main.kcl'
       )
 
       await u.openFilePanel()
       await expect(
-        page.getByTestId('file-tree-item').getByText('2x2x2-cube.kcl')
+        page.getByTestId('file-tree-item').getByText('2x2x2-cube')
       ).toBeVisible()
     }
   )
@@ -1184,13 +1184,13 @@ test.describe('Mocked Text-to-CAD API tests', { tag: ['@skipWin'] }, () => {
       )
       await expect(page.getByTestId('app-header-file-name')).toBeVisible()
       await expect(page.getByTestId('app-header-file-name')).toContainText(
-        '2x2x2-cube.kcl'
+        'main.kcl'
       )
 
       // Check file is created
       await u.openFilePanel()
       await expect(
-        page.getByTestId('file-tree-item').getByText('2x2x2-cube.kcl')
+        page.getByTestId('file-tree-item').getByText('2x2x2-cube')
       ).toBeVisible()
     }
   )
@@ -1476,13 +1476,13 @@ test.describe('Mocked Text-to-CAD API tests', { tag: ['@skipWin'] }, () => {
       )
       await expect(page.getByTestId('app-header-file-name')).toBeVisible()
       await expect(page.getByTestId('app-header-file-name')).toContainText(
-        '2x2x2-cube.kcl'
+        'main.kcl'
       )
 
       // Check file is created
       await u.openFilePanel()
       await expect(
-        page.getByTestId('file-tree-item').getByText('2x2x2-cube.kcl')
+        page.getByTestId('file-tree-item').getByText('2x2x2-cube')
       ).toBeVisible()
       await expect(
         page.getByTestId('file-tree-item').getByText('main.kcl')

e2e/playwright/various.spec.ts

@@ -573,6 +573,7 @@ profile001 = startProfile(sketch002, at = [-12.34, 12.34])
   await expect(page.getByTestId('command-bar')).toBeVisible()
   await page.waitForTimeout(100)
 
+  await cmdBar.progressCmdBar()
   await cmdBar.progressCmdBar()
   await expect(page.getByText('Confirm Extrude')).toBeVisible()
   await cmdBar.progressCmdBar()

public/kcl-samples/README.md

@@ -37,6 +37,8 @@ When you submit a PR to add or modify KCL samples, images will be generated and
 [![bottle](screenshots/bottle.png)](bottle/main.kcl)
 #### [bracket](bracket/main.kcl) ([screenshot](screenshots/bracket.png))
 [![bracket](screenshots/bracket.png)](bracket/main.kcl)
+#### [brake-rotor](brake-rotor/main.kcl) ([screenshot](screenshots/brake-rotor.png))
+[![brake-rotor](screenshots/brake-rotor.png)](brake-rotor/main.kcl)
 #### [car-wheel-assembly](car-wheel-assembly/main.kcl) ([screenshot](screenshots/car-wheel-assembly.png))
 [![car-wheel-assembly](screenshots/car-wheel-assembly.png)](car-wheel-assembly/main.kcl)
 #### [cold-plate](cold-plate/main.kcl) ([screenshot](screenshots/cold-plate.png))

public/kcl-samples/brake-rotor/main.kcl

@@ -0,0 +1,179 @@
+// A 320mm vented brake disc (rotor), with straight vanes, 30mm thick. The disc bell should accommodate 5 M12 wheel studs on a 114.3mm pitch circle diameter.
+
+
+
+
+@settings(defaultLengthUnit = mm)
+
+// Define parameters.
+dDisc = 320
+dPitchCircle = 114.3
+dBore = 64
+nStuds = 5
+dStudDrilling = 12.5 // M12
+hFrictionSurface = 60
+tDiscHalf = 10
+
+// Vent parameters.
+tVent = 10
+wVent = 6
+rVentFillet = 2
+nVentBosses = 36
+
+// Drilling parameters.
+dDrillDia = 6
+aBase = 90
+aSweep = 30
+nArcs = 12
+
+// Bell parameters.
+aDraftBell = 5
+tBell = 5 // Wall thickness.
+hBellAboveDiscFace = 40
+hBellSubflush = 4
+wUndercut = 8
+
+fn drillHole(activeSketch, t) {
+  // Sketch a vent hole at line parameter value t on an arc drawn across the disc surface.
+  rInner = dDisc / 2 - hFrictionSurface
+  rOuter = dDisc / 2
+
+  aStart = aBase
+  aEnd = aBase - aSweep
+
+  // Linear interpolation of radius.
+  rCurrent = rInner + t * (rOuter - rInner)
+
+  // Linear interpolation of angle.
+  aCurrent = aStart + t * (aEnd - aStart)
+
+  // Calculate position.
+  xCenter = rCurrent * cos(aCurrent)
+  yCenter = rCurrent * sin(aCurrent)
+
+  // Draw.
+  drillCircle = circle(activeSketch, center = [xCenter, yCenter], radius = dDrillDia / 2)
+  return drillCircle
+}
+
+fn createDiscHalf(plane, dDiscParam, hFrictionSurfaceParam, tDiscHalfParam) {
+  // Create a disc half with a vent hole pattern.
+  sketchFace = startSketchOn(plane)
+  profileFace = circle(sketchFace, center = [0, 0], radius = dDiscParam / 2)
+    |> subtract2d(tool = circle(sketchFace, center = [0, 0], radius = dDiscParam / 2 - hFrictionSurfaceParam))
+
+  // Create three circles at t = 0, 0.5, and 1
+  hole1 = drillHole(activeSketch = sketchFace, t = 0.2)
+  hole2 = drillHole(activeSketch = sketchFace, t = 0.5)
+  hole3 = drillHole(activeSketch = sketchFace, t = 0.8)
+
+  // Pattern and cut.
+  holes = patternCircular2d(
+    [hole1, hole2, hole3],
+    instances = nArcs,
+    center = [0, 0],
+    arcDegrees = 360,
+    rotateDuplicates = true,
+  )
+  profileDrilled = subtract2d(profileFace, tool = holes)
+
+  // Extrude.
+  discHalf = extrude(profileFace, length = tDiscHalfParam)
+  return discHalf
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+
+// Create inboard half.
+discInboard = createDiscHalf(
+  plane = XY,
+  dDiscParam = dDisc,
+  hFrictionSurfaceParam = hFrictionSurface,
+  tDiscHalfParam = tDiscHalf,
+)
+
+// Create vents.
+planeVent = offsetPlane(XY, offset = tDiscHalf)
+sketchVent = startSketchOn(planeVent)
+profileVent = startProfile(sketchVent, at = [-wVent, dDisc / 2])
+  |> angledLine(angle = 0, length = wVent, tag = $rectangleSegmentA001)
+  |> angledLine(angle = segAng(rectangleSegmentA001) - 90, length = hFrictionSurface, tag = $seg02)
+  |> angledLine(angle = segAng(rectangleSegmentA001), length = -segLen(rectangleSegmentA001), tag = $seg03)
+  |> line(endAbsolute = [profileStartX(%), profileStartY(%)], tag = $seg01)
+  |> close()
+
+ventPad = extrude(profileVent, length = tVent)
+  |> fillet(
+       radius = rVentFillet,
+       tags = [
+         getCommonEdge(faces = [seg01, rectangleSegmentA001]),
+         getCommonEdge(faces = [seg02, rectangleSegmentA001]),
+         getCommonEdge(faces = [seg01, seg03]),
+         getCommonEdge(faces = [seg03, seg02])
+       ],
+     )
+ventSet = patternCircular3d(
+  ventPad,
+  instances = nVentBosses,
+  axis = [0, 0, 1],
+  center = [0, 0, tDiscHalf],
+  arcDegrees = 360,
+  rotateDuplicates = true,
+)
+
+// Create outboard half.
+planeOutboard = offsetPlane(XY, offset = tDiscHalf + tVent)
+discOutboard = createDiscHalf(
+  plane = planeOutboard,
+  dDiscParam = dDisc,
+  hFrictionSurfaceParam = hFrictionSurface,
+  tDiscHalfParam = tDiscHalf,
+)
+
+// Now create bell.
+rCenter = dDisc / 2 - hFrictionSurface - wUndercut
+rBore = dBore / 2
+lDraftExterior = hBellAboveDiscFace / tan(90 - aDraftBell)
+lDraftInterior = (hBellAboveDiscFace - tBell) / tan(90 - aDraftBell)
+
+// Inner and outer radius of outboard face of disc bell.
+rOuter = rCenter - lDraftExterior - rBore
+rInner = rOuter + lDraftExterior - (tBell + lDraftInterior)
+
+sketchDiscBell = startSketchOn(-YZ)
+bodyDiscBell = startProfile(
+       sketchDiscBell,
+       at = [
+         -dDisc / 2 + hFrictionSurface,
+         tDiscHalf * 2 + tVent
+       ],
+     )
+  |> arc(
+       %,
+       angleStart = -180,
+       angleEnd = 0,
+       radius = wUndercut / 2,
+     )
+  |> line(end = [lDraftExterior, hBellAboveDiscFace])
+  |> xLine(length = rOuter, tag = $seg04)
+  |> yLine(length = -tBell)
+  |> xLine(length = -rInner)
+  |> line(end = [-lDraftInterior, -hBellAboveDiscFace])
+  |> line(end = [0, -2]) // Wall thickness.
+  |> xLine(length = -1 * (tBell + wUndercut))
+  |> close(%)
+  |> revolve(axis = Y)
+
+// Drill lug holes.
+sketchLugs = startSketchOn(bodyDiscBell, face = seg04)
+profileStud = circle(sketchLugs, center = [0, dPitchCircle / 2], radius = dStudDrilling / 2)
+  |> patternCircular2d(
+       %,
+       instances = nStuds,
+       center = [0, 0],
+       arcDegrees = 360,
+       rotateDuplicates = true,
+     )
+
+clearance = 2 // Some margin on negative extrude.
+lugs = extrude(profileStud, length = -1 * (tBell + clearance))

public/kcl-samples/manifest.json

@@ -74,6 +74,16 @@
       "main.kcl"
     ]
   },
+  {
+    "file": "main.kcl",
+    "pathFromProjectDirectoryToFirstFile": "brake-rotor/main.kcl",
+    "multipleFiles": false,
+    "title": "A 320mm vented brake disc (rotor), with straight vanes, 30mm thick. The disc bell should accommodate 5 M12 wheel studs on a 114.3mm pitch circle diameter.",
+    "description": "",
+    "files": [
+      "main.kcl"
+    ]
+  },
   {
     "file": "main.kcl",
     "pathFromProjectDirectoryToFirstFile": "car-wheel-assembly/main.kcl",

public/kcl-samples/pdu-faceplate/main.kcl

@@ -72,25 +72,25 @@ leftSpacerShape = boxModuleFn(width = leftSpacerWidth)
 
 // Module for power switch including front plate and red rocker button
 switchPosition = leftSpacerPosition + leftSpacerWidth / 2 + moduleWidth / 2
-swtichWidth = moduleWidth
+switchWidth = moduleWidth
 
 // Switch Body
 switchBody = boxModuleFn(width = moduleWidth)
 
 // Switch Plate
-swtichPlateWidth = 20
+switchPlateWidth = 20
 switchPlateHeight = 30
 switchPlateThickness = 3
 switchPlateShape = startSketchOn(switchBody, face = END)
   |> startProfile(
        %,
        at = [
-         -swtichPlateWidth / 2,
+         -switchPlateWidth / 2,
          -switchPlateHeight / 2
        ],
      )
   |> yLine(length = switchPlateHeight)
-  |> xLine(length = swtichPlateWidth)
+  |> xLine(length = switchPlateWidth)
   |> yLine(length = -switchPlateHeight)
   |> line(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
@@ -104,8 +104,8 @@ switchPlateBody = extrude(switchPlateShape, length = switchPlateThickness)
 
 // Switch Button
 switchButtonHeight = 26
-swtichButtonWidth = 15
+switchButtonWidth = 15
-switchButtonShape = startSketchOn(offsetPlane(-YZ, offset = -swtichButtonWidth / 2))
+switchButtonShape = startSketchOn(offsetPlane(-YZ, offset = -switchButtonWidth / 2))
   |> startProfile(
        %,
        at = [
@@ -121,7 +121,7 @@ switchButtonShape = startSketchOn(offsetPlane(-YZ, offset = -swtichButtonWidth /
      ])
   |> line(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
-switchButtonBody = extrude(switchButtonShape, length = swtichButtonWidth)
+switchButtonBody = extrude(switchButtonShape, length = switchButtonWidth)
   |> translate(
        %,
        x = switchPosition,
@@ -132,7 +132,7 @@ switchButtonBody = extrude(switchButtonShape, length = swtichButtonWidth)
 
 // Spacer between switch and plug modules for layout alignment
 secondSpacerWidth = moduleWidth / 2
-secondSpacerPosition = switchPosition + swtichWidth / 2 + secondSpacerWidth / 2
+secondSpacerPosition = switchPosition + switchWidth / 2 + secondSpacerWidth / 2
 secondSpacerBody = boxModuleFn(width = secondSpacerWidth)
   |> translate(
        %,

public/kcl-samples/prosthetic-hip/main.kcl

@@ -33,14 +33,9 @@ stemLoftProfile2 = startSketchOn(offsetPlane(XY, offset = 75))
 // Draw the third profile for the lofted femur
 p3Z = 110
 p3A = 25
-plane003 = {
-  origin = [0, 0.0, p3Z],
-  xAxis = [cos(p3A), 0, sin(p3A)],
-  yAxis = [0.0, 1.0, 0.0]
-}
 l3 = 32
 r3 = 4
-stemLoftProfile3 = startSketchOn(plane003)
+stemLoftProfile3 = startSketchOn(XY)
   |> startProfile(at = [-15.5, -l3 / 2])
   |> yLine(length = l3, tag = $seg03)
   |> tangentialArc(angle = -120, radius = r3)
@@ -49,18 +44,14 @@ stemLoftProfile3 = startSketchOn(plane003)
   |> angledLine(angle = 30, length = -segLen(seg03))
   |> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
-
+  |> translate(z = p3Z)
+  |> rotate(pitch = -p3A)
 // Draw the fourth profile for the lofted femur
 p4Z = 130
 p4A = 36.5
-plane004 = {
-  origin = [0, 0.0, p4Z],
-  xAxis = [cos(p4A), 0, sin(p4A)],
-  yAxis = [0.0, 1.0, 0.0]
-}
 l4 = 16
 r4 = 5
-stemLoftProfile4 = startSketchOn(plane004)
+stemLoftProfile4 = startSketchOn(XY)
   |> startProfile(at = [-23, -l4 / 2])
   |> yLine(length = l4, tag = $seg04)
   |> tangentialArc(angle = -120, radius = r4)
@@ -69,18 +60,14 @@ stemLoftProfile4 = startSketchOn(plane004)
   |> angledLine(angle = 30, length = -segLen(seg04))
   |> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
-
+  |> translate(z = p4Z)
+  |> rotate(pitch = -p4A)
 // Draw the first profile for the femoral stem
 p5Z = 140
 p5A = 36.5
-plane005 = {
-  origin = [0, 0.0, p5Z],
-  xAxis = [cos(p5A), 0, sin(p5A)],
-  yAxis = [0.0, 1.0, 0.0]
-}
 l5 = 1.6
 r5 = 1.6
-stemLoftProfile5 = startSketchOn(plane005)
+stemLoftProfile5 = startSketchOn(XY)
   |> startProfile(at = [-19.5, -l5 / 2])
   |> yLine(length = l5, tag = $seg05)
   |> tangentialArc(angle = -120, radius = r5)
@@ -89,18 +76,14 @@ stemLoftProfile5 = startSketchOn(plane005)
   |> angledLine(angle = 30, length = -segLen(seg05))
   |> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
-
+  |> translate(z = p5Z)
+  |> rotate(pitch = -p5A)
 // Draw the second profile for the femoral stem
 p6Z = 145
 p6A = 36.5
-plane006 = {
-  origin = [0, 0.0, p6Z],
-  xAxis = [cos(p6A), 0, sin(p6A)],
-  yAxis = [0.0, 1.0, 0.0]
-}
 l6 = 1
 r6 = 3
-stemLoftProfile6 = startSketchOn(plane006)
+stemLoftProfile6 = startSketchOn(XY)
   |> startProfile(at = [-23.4, -l6 / 2])
   |> yLine(length = l6, tag = $seg06)
   |> tangentialArc(angle = -120, radius = r6)
@@ -109,27 +92,24 @@ stemLoftProfile6 = startSketchOn(plane006)
   |> angledLine(angle = 30, length = -segLen(seg06))
   |> tangentialArc(endAbsolute = [profileStartX(%), profileStartY(%)])
   |> close()
-
+  |> translate(z = p6Z)
-// Draw the third profile for the femoral stem
+  |> rotate(pitch = -p6A)
-stemTab = clone(stemLoftProfile6)
-  |> extrude(%, length = 6)
-
 // Loft the femur using all profiles in sequence
-
 femur = loft([
   stemLoftProfile1,
   stemLoftProfile2,
   stemLoftProfile3,
   stemLoftProfile4
 ])
-
 // Loft the femoral stem
 femoralStem = loft([
   clone(stemLoftProfile4),
   stemLoftProfile5,
-  stemLoftProfile6
+  clone(stemLoftProfile6)
 ])
-
+// Draw the third profile for the femoral stem
+stemTab = stemLoftProfile6
+  |> extrude(length = 6)
 // Revolve a hollow socket to represent the femoral head
 femoralHead = startSketchOn(XZ)
   |> startProfile(at = [4, 0])

public/kcl-samples/spinning-highrise-tower/main.kcl

@@ -53,8 +53,8 @@ baseSlab = boxFn(plane = XY, width = slabWidth, height = -baseThickness)
   |> appearance(%, color = "#dbd7d2")
 
 // Create ground platform beneath the base
-goundSize = 50
+groundSize = 50
-groundBody = boxFn(plane = offsetPlane(XY, offset = -baseThickness), width = goundSize, height = -5)
+groundBody = boxFn(plane = offsetPlane(XY, offset = -baseThickness), width = groundSize, height = -5)
   |> appearance(%, color = "#3a3631")
 
 // Create a single slab with handrail height to be reused with pattern

rust/Cargo.lock

@@ -1815,7 +1815,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-bumper"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "anyhow",
  "clap",
@@ -1826,7 +1826,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-derive-docs"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "Inflector",
  "anyhow",
@@ -1845,7 +1845,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-directory-test-macro"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "convert_case",
  "proc-macro2",
@@ -1855,7 +1855,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-language-server"
-version = "0.2.74"
+version = "0.2.75"
 dependencies = [
  "anyhow",
  "clap",
@@ -1876,7 +1876,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-language-server-release"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "anyhow",
  "clap",
@@ -1896,7 +1896,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-lib"
-version = "0.2.74"
+version = "0.2.75"
 dependencies = [
  "anyhow",
  "approx 0.5.1",
@@ -1973,7 +1973,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-python-bindings"
-version = "0.3.74"
+version = "0.3.75"
 dependencies = [
  "anyhow",
  "kcl-lib",
@@ -1988,7 +1988,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-test-server"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "anyhow",
  "hyper 0.14.32",
@@ -2001,7 +2001,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-to-core"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -2015,7 +2015,7 @@ dependencies = [
 
 [[package]]
 name = "kcl-wasm-lib"
-version = "0.1.74"
+version = "0.1.75"
 dependencies = [
  "anyhow",
  "bson",

rust/kcl-bumper/Cargo.toml

@@ -1,7 +1,7 @@
 
 [package]
 name = "kcl-bumper"
-version = "0.1.74"
+version = "0.1.75"
 edition = "2021"
 repository = "https://github.com/KittyCAD/modeling-api"
 rust-version = "1.76"

rust/kcl-derive-docs/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "kcl-derive-docs"
 description = "A tool for generating documentation from Rust derive macros"
-version = "0.1.74"
+version = "0.1.75"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/KittyCAD/modeling-app"

rust/kcl-directory-test-macro/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "kcl-directory-test-macro"
 description = "A tool for generating tests from a directory of kcl files"
-version = "0.1.74"
+version = "0.1.75"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/KittyCAD/modeling-app"

rust/kcl-language-server-release/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "kcl-language-server-release"
-version = "0.1.74"
+version = "0.1.75"
 edition = "2021"
 authors = ["KittyCAD Inc <kcl@kittycad.io>"]
 publish = false

rust/kcl-language-server/Cargo.toml

@@ -2,7 +2,7 @@
 name = "kcl-language-server"
 description = "A language server for KCL."
 authors = ["KittyCAD Inc <kcl@kittycad.io>"]
-version = "0.2.74"
+version = "0.2.75"
 edition = "2021"
 license = "MIT"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

rust/kcl-lib/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "kcl-lib"
 description = "KittyCAD Language implementation and tools"
-version = "0.2.74"
+version = "0.2.75"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/KittyCAD/modeling-app"

rust/kcl-lib/e2e/executor/main.rs

@@ -2,7 +2,7 @@ mod cache;
 
 use kcl_lib::{
     test_server::{execute_and_export_step, execute_and_snapshot, execute_and_snapshot_no_auth},
-    ExecError,
+    BacktraceItem, ExecError, ModuleId, SourceRange,
 };
 
 /// The minimum permissible difference between asserted twenty-twenty images.
@@ -441,10 +441,15 @@ async fn kcl_test_import_file_doesnt_exist() {
 model = cube"#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "File `thing.obj` does not exist.");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([0, 18, 0])], message: "File `thing.obj` does not exist." }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(0, 18, ModuleId::default()),
+            fn_name: None,
+        }]
     );
 }
 
@@ -519,10 +524,18 @@ import 'e2e/executor/inputs/cube.gltf'
 model = cube"#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.message(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([32, 70, 0])], message: "The given format does not match the file extension. Expected: `gltf`, Given: `obj`" }"#
+        "The given format does not match the file extension. Expected: `gltf`, Given: `obj`"
+    );
+    assert_eq!(
+        err.backtrace(),
+        vec![BacktraceItem {
+            source_range: SourceRange::new(32, 70, ModuleId::default()),
+            fn_name: None,
+        }]
     );
 }
 
@@ -1666,10 +1679,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 90 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 111, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 111, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1686,10 +1704,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 270 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 112, 0])], message: "Cannot have an x constrained angle of 270 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 112, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1706,10 +1729,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 0 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 110, 0])], message: "Cannot have a y constrained angle of 0 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 110, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1726,10 +1754,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([70, 112, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(70, 112, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1746,10 +1779,15 @@ extrusion = extrude(sketch001, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 90 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([66, 116, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(66, 116, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1757,7 +1795,7 @@ extrusion = extrude(sketch001, length = 10)
 async fn kcl_test_angled_line_of_x_length_270() {
     let code = r#"sketch001 = startSketchOn(XZ)
   |> startProfile(at = [0, 0])
-  |> angledLine(angle = 90, lengthX = 90, tag = $edge1)
+  |> angledLine(angle = 270, lengthX = 90, tag = $edge1)
   |> angledLine(angle = -15, lengthX = -15, tag = $edge2)
   |> line(end = [0, -5])
   |> close(tag = $edge3)
@@ -1766,10 +1804,15 @@ extrusion = extrude(sketch001, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have an x constrained angle of 270 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([66, 116, 0])], message: "Cannot have an x constrained angle of 90 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(66, 117, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1788,10 +1831,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 0 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 130, 0])], message: "Cannot have a y constrained angle of 0 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 130, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1810,10 +1858,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 132, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 132, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1832,10 +1885,15 @@ example = extrude(exampleSketch, length = 10)
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
+    assert_eq!(err.message(), "Cannot have a y constrained angle of 180 degrees");
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.backtrace(),
-        r#"type: KclErrorDetails { source_ranges: [SourceRange([95, 133, 0])], message: "Cannot have a y constrained angle of 180 degrees" }"#
+        vec![BacktraceItem {
+            source_range: SourceRange::new(95, 133, ModuleId::default()),
+            fn_name: Some("angledLine".to_owned())
+        }]
     );
 }
 
@@ -1849,10 +1907,31 @@ someFunction('INVALID')
 "#;
 
     let result = execute_and_snapshot(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
+    let err = err.as_kcl_error().unwrap();
     assert_eq!(
-        result.err().unwrap().to_string(),
+        err.message(),
-        r#"semantic: KclErrorDetails { source_ranges: [SourceRange([46, 55, 0]), SourceRange([60, 83, 0])], message: "This function expected the input argument to be Solid or Plane but it's actually of type string" }"#
+        "This function expected the input argument to be Solid or Plane but it's actually of type string"
+    );
+    assert_eq!(
+        err.source_ranges(),
+        vec![
+            SourceRange::new(46, 55, ModuleId::default()),
+            SourceRange::new(60, 83, ModuleId::default()),
+        ]
+    );
+    assert_eq!(
+        err.backtrace(),
+        vec![
+            BacktraceItem {
+                source_range: SourceRange::new(46, 55, ModuleId::default()),
+                fn_name: Some("someFunction".to_owned()),
+            },
+            BacktraceItem {
+                source_range: SourceRange::new(60, 83, ModuleId::default()),
+                fn_name: None,
+            },
+        ]
     );
 }
 
@@ -1873,12 +1952,14 @@ async fn kcl_test_error_no_auth_websocket() {
 "#;
 
     let result = execute_and_snapshot_no_auth(code, None).await;
-    assert!(result.is_err());
+    let err = result.unwrap_err();
-    assert!(result
+    let err = err.as_kcl_error().unwrap();
-        .err()
+    assert!(
-        .unwrap()
+        err.message()
-        .to_string()
+            .contains("Please send the following object over this websocket"),
-        .contains("Please send the following object over this websocket"));
+        "actual: {}",
+        err.message()
+    );
 }
 
 #[tokio::test(flavor = "multi_thread")]

rust/kcl-lib/src/docs/kcl_doc.rs

@@ -631,6 +631,8 @@ impl FnData {
             return "clone(${0:part001})".to_owned();
         } else if self.name == "hole" {
             return "hole(${0:holeSketch}, ${1:%})".to_owned();
+        } else if self.name == "circle" {
+            return "circle(center = [${0:3.14}, ${1:3.14}], diameter = ${2:3.14})".to_owned();
         }
         let mut args = Vec::new();
         let mut index = 0;

rust/kcl-lib/src/docs/mod.rs

@@ -1018,7 +1018,7 @@ mod tests {
         let snippet = circle_fn.to_autocomplete_snippet();
         assert_eq!(
             snippet,
-            r#"circle(center = [${0:3.14}, ${1:3.14}], radius = ${2:3.14})"#
+            r#"circle(center = [${0:3.14}, ${1:3.14}], diameter = ${2:3.14})"#
         );
     }
 

rust/kcl-lib/src/engine/conn.rs

@@ -439,12 +439,7 @@ impl EngineManager for EngineConnection {
                 request_sent: tx,
             })
             .await
-            .map_err(|e| {
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(format!("Failed to send debug: {}", e), vec![])))?;
-                KclError::Engine(KclErrorDetails {
-                    message: format!("Failed to send debug: {}", e),
-                    source_ranges: vec![],
-                })
-            })?;
 
         let _ = rx.await;
         Ok(())
@@ -479,25 +474,25 @@ impl EngineManager for EngineConnection {
             })
             .await
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: format!("Failed to send modeling command: {}", e),
+                    format!("Failed to send modeling command: {}", e),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             })?;
 
         // Wait for the request to be sent.
         rx.await
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: format!("could not send request to the engine actor: {e}"),
+                    format!("could not send request to the engine actor: {e}"),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             })?
             .map_err(|e| {
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: format!("could not send request to the engine: {e}"),
+                    format!("could not send request to the engine: {e}"),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             })?;
 
         Ok(())
@@ -521,15 +516,15 @@ impl EngineManager for EngineConnection {
                 // Check if we have any pending errors.
                 let pe = self.pending_errors.read().await;
                 if !pe.is_empty() {
-                    return Err(KclError::Engine(KclErrorDetails {
+                    return Err(KclError::Engine(KclErrorDetails::new(
-                        message: pe.join(", ").to_string(),
+                        pe.join(", ").to_string(),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    }));
+                    )));
                 } else {
-                    return Err(KclError::Engine(KclErrorDetails {
+                    return Err(KclError::Engine(KclErrorDetails::new(
-                        message: "Modeling command failed: websocket closed early".to_string(),
+                        "Modeling command failed: websocket closed early".to_string(),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    }));
+                    )));
                 }
             }
 
@@ -548,10 +543,10 @@ impl EngineManager for EngineConnection {
             }
         }
 
-        Err(KclError::Engine(KclErrorDetails {
+        Err(KclError::Engine(KclErrorDetails::new(
-            message: format!("Modeling command timed out `{}`", id),
+            format!("Modeling command timed out `{}`", id),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }))
+        )))
     }
 
     async fn get_session_data(&self) -> Option<ModelingSessionData> {

rust/kcl-lib/src/engine/conn_wasm.rs

@@ -147,32 +147,27 @@ impl EngineConnection {
         id_to_source_range: HashMap<uuid::Uuid, SourceRange>,
     ) -> Result<(), KclError> {
         let source_range_str = serde_json::to_string(&source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize source range: {:?}", e),
+                format!("Failed to serialize source range: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
         let cmd_str = serde_json::to_string(&cmd).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize modeling command: {:?}", e),
+                format!("Failed to serialize modeling command: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
         let id_to_source_range_str = serde_json::to_string(&id_to_source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize id to source range: {:?}", e),
+                format!("Failed to serialize id to source range: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         self.manager
             .fire_modeling_cmd_from_wasm(id.to_string(), source_range_str, cmd_str, id_to_source_range_str)
-            .map_err(|e| {
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-                KclError::Engine(KclErrorDetails {
-                    message: e.to_string().into(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
 
         Ok(())
     }
@@ -185,33 +180,28 @@ impl EngineConnection {
         id_to_source_range: HashMap<uuid::Uuid, SourceRange>,
     ) -> Result<WebSocketResponse, KclError> {
         let source_range_str = serde_json::to_string(&source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize source range: {:?}", e),
+                format!("Failed to serialize source range: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
         let cmd_str = serde_json::to_string(&cmd).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize modeling command: {:?}", e),
+                format!("Failed to serialize modeling command: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
         let id_to_source_range_str = serde_json::to_string(&id_to_source_range).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to serialize id to source range: {:?}", e),
+                format!("Failed to serialize id to source range: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         let promise = self
             .manager
             .send_modeling_cmd_from_wasm(id.to_string(), source_range_str, cmd_str, id_to_source_range_str)
-            .map_err(|e| {
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-                KclError::Engine(KclErrorDetails {
-                    message: e.to_string().into(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
 
         let value = crate::wasm::JsFuture::from(promise).await.map_err(|e| {
             // Try to parse the error as an engine error.
@@ -219,53 +209,52 @@ impl EngineConnection {
             if let Ok(kittycad_modeling_cmds::websocket::FailureWebSocketResponse { errors, .. }) =
                 serde_json::from_str(&err_str)
             {
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
+                    errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             } else if let Ok(data) =
                 serde_json::from_str::<Vec<kittycad_modeling_cmds::websocket::FailureWebSocketResponse>>(&err_str)
             {
                 if let Some(data) = data.first() {
                     // It could also be an array of responses.
-                    KclError::Engine(KclErrorDetails {
+                    KclError::Engine(KclErrorDetails::new(
-                        message: data
+                        data.errors
-                            .errors
                             .iter()
                             .map(|e| e.message.clone())
                             .collect::<Vec<_>>()
                             .join("\n"),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    })
+                    ))
                 } else {
-                    KclError::Engine(KclErrorDetails {
+                    KclError::Engine(KclErrorDetails::new(
-                        message: "Received empty response from engine".into(),
+                        "Received empty response from engine".into(),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    })
+                    ))
                 }
             } else {
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: format!("Failed to wait for promise from send modeling command: {:?}", e),
+                    format!("Failed to wait for promise from send modeling command: {:?}", e),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             }
         })?;
 
         if value.is_null() || value.is_undefined() {
-            return Err(KclError::Engine(KclErrorDetails {
+            return Err(KclError::Engine(KclErrorDetails::new(
-                message: "Received null or undefined response from engine".into(),
+                "Received null or undefined response from engine".into(),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            }));
+            )));
         }
 
         // Convert JsValue to a Uint8Array
         let data = js_sys::Uint8Array::from(value);
 
         let ws_result: WebSocketResponse = bson::from_slice(&data.to_vec()).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to deserialize bson response from engine: {:?}", e),
+                format!("Failed to deserialize bson response from engine: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         Ok(ws_result)
@@ -316,18 +305,16 @@ impl crate::engine::EngineManager for EngineConnection {
         *self.default_planes.write().await = Some(new_planes);
 
         // Start a new session.
-        let promise = self.manager.start_new_session().map_err(|e| {
+        let promise = self
-            KclError::Engine(KclErrorDetails {
+            .manager
-                message: e.to_string().into(),
+            .start_new_session()
-                source_ranges: vec![source_range],
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-            })
-        })?;
 
         crate::wasm::JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to wait for promise from start new session: {:?}", e),
+                format!("Failed to wait for promise from start new session: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         Ok(())

rust/kcl-lib/src/engine/mod.rs

@@ -276,10 +276,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 {
                     let duration = instant::Duration::from_millis(1);
                     wasm_timer::Delay::new(duration).await.map_err(|err| {
-                        KclError::Internal(KclErrorDetails {
+                        KclError::Internal(KclErrorDetails::new(
-                            message: format!("Failed to sleep: {:?}", err),
+                            format!("Failed to sleep: {:?}", err),
-                            source_ranges: vec![source_range],
+                            vec![source_range],
-                        })
+                        ))
                     })?;
                 }
                 #[cfg(not(target_arch = "wasm32"))]
@@ -293,10 +293,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
             return Ok(response);
         }
 
-        Err(KclError::Engine(KclErrorDetails {
+        Err(KclError::Engine(KclErrorDetails::new(
-            message: "async command timed out".to_string(),
+            "async command timed out".to_string(),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }))
+        )))
     }
 
     /// Ensure ALL async commands have been completed.
@@ -547,10 +547,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                     id_to_source_range.insert(Uuid::from(*cmd_id), *range);
                 }
                 _ => {
-                    return Err(KclError::Engine(KclErrorDetails {
+                    return Err(KclError::Engine(KclErrorDetails::new(
-                        message: format!("The request is not a modeling command: {:?}", req),
+                        format!("The request is not a modeling command: {:?}", req),
-                        source_ranges: vec![*range],
+                        vec![*range],
-                    }));
+                    )));
                 }
             }
         }
@@ -595,10 +595,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                     self.parse_batch_responses(last_id.into(), id_to_source_range, responses)
                 } else {
                     // We should never get here.
-                    Err(KclError::Engine(KclErrorDetails {
+                    Err(KclError::Engine(KclErrorDetails::new(
-                        message: format!("Failed to get batch response: {:?}", response),
+                        format!("Failed to get batch response: {:?}", response),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    }))
+                    )))
                 }
             }
             WebSocketRequest::ModelingCmdReq(ModelingCmdReq { cmd: _, cmd_id }) => {
@@ -610,20 +610,20 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 // request so we need the original request source range in case the engine returns
                 // an error.
                 let source_range = id_to_source_range.get(cmd_id.as_ref()).cloned().ok_or_else(|| {
-                    KclError::Engine(KclErrorDetails {
+                    KclError::Engine(KclErrorDetails::new(
-                        message: format!("Failed to get source range for command ID: {:?}", cmd_id),
+                        format!("Failed to get source range for command ID: {:?}", cmd_id),
-                        source_ranges: vec![],
+                        vec![],
-                    })
+                    ))
                 })?;
                 let ws_resp = self
                     .inner_send_modeling_cmd(cmd_id.into(), source_range, final_req, id_to_source_range)
                     .await?;
                 self.parse_websocket_response(ws_resp, source_range)
             }
-            _ => Err(KclError::Engine(KclErrorDetails {
+            _ => Err(KclError::Engine(KclErrorDetails::new(
-                message: format!("The final request is not a modeling command: {:?}", final_req),
+                format!("The final request is not a modeling command: {:?}", final_req),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })),
+            ))),
         }
     }
 
@@ -729,10 +729,10 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
         for (name, plane_id, color) in plane_settings {
             let info = DEFAULT_PLANE_INFO.get(&name).ok_or_else(|| {
                 // We should never get here.
-                KclError::Engine(KclErrorDetails {
+                KclError::Engine(KclErrorDetails::new(
-                    message: format!("Failed to get default plane info for: {:?}", name),
+                    format!("Failed to get default plane info for: {:?}", name),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             })?;
             planes.insert(
                 name,
@@ -763,15 +763,14 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
             WebSocketResponse::Success(success) => Ok(success.resp),
             WebSocketResponse::Failure(fail) => {
                 let _request_id = fail.request_id;
-                Err(KclError::Engine(KclErrorDetails {
+                Err(KclError::Engine(KclErrorDetails::new(
-                    message: fail
+                    fail.errors
-                        .errors
                         .iter()
                         .map(|e| e.message.clone())
                         .collect::<Vec<_>>()
                         .join("\n"),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                }))
+                )))
             }
         }
     }
@@ -806,25 +805,25 @@ pub trait EngineManager: std::fmt::Debug + Send + Sync + 'static {
                 BatchResponse::Failure { errors } => {
                     // Get the source range for the command.
                     let source_range = id_to_source_range.get(cmd_id).cloned().ok_or_else(|| {
-                        KclError::Engine(KclErrorDetails {
+                        KclError::Engine(KclErrorDetails::new(
-                            message: format!("Failed to get source range for command ID: {:?}", cmd_id),
+                            format!("Failed to get source range for command ID: {:?}", cmd_id),
-                            source_ranges: vec![],
+                            vec![],
-                        })
+                        ))
                     })?;
-                    return Err(KclError::Engine(KclErrorDetails {
+                    return Err(KclError::Engine(KclErrorDetails::new(
-                        message: errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
+                        errors.iter().map(|e| e.message.clone()).collect::<Vec<_>>().join("\n"),
-                        source_ranges: vec![source_range],
+                        vec![source_range],
-                    }));
+                    )));
                 }
             }
         }
 
         // Return an error that we did not get an error or the response we wanted.
         // This should never happen but who knows.
-        Err(KclError::Engine(KclErrorDetails {
+        Err(KclError::Engine(KclErrorDetails::new(
-            message: format!("Failed to find response for command ID: {:?}", id),
+            format!("Failed to find response for command ID: {:?}", id),
-            source_ranges: vec![],
+            vec![],
-        }))
+        )))
     }
 
     async fn modify_grid(

rust/kcl-lib/src/errors.rs

@@ -380,20 +380,39 @@ impl miette::Diagnostic for Report {
 }
 
 #[derive(Debug, Serialize, Deserialize, ts_rs::TS, Clone, PartialEq, Eq, thiserror::Error, miette::Diagnostic)]
+#[serde(rename_all = "camelCase")]
 #[error("{message}")]
 #[ts(export)]
 pub struct KclErrorDetails {
-    #[serde(rename = "sourceRanges")]
     #[label(collection, "Errors")]
     pub source_ranges: Vec<SourceRange>,
+    pub backtrace: Vec<BacktraceItem>,
     #[serde(rename = "msg")]
     pub message: String,
 }
 
+impl KclErrorDetails {
+    pub fn new(message: String, source_ranges: Vec<SourceRange>) -> KclErrorDetails {
+        let backtrace = source_ranges
+            .iter()
+            .map(|s| BacktraceItem {
+                source_range: *s,
+                fn_name: None,
+            })
+            .collect();
+        KclErrorDetails {
+            source_ranges,
+            backtrace,
+            message,
+        }
+    }
+}
+
 impl KclError {
     pub fn internal(message: String) -> KclError {
         KclError::Internal(KclErrorDetails {
             source_ranges: Default::default(),
+            backtrace: Default::default(),
             message,
         })
     }
@@ -455,45 +474,122 @@ impl KclError {
         }
     }
 
+    pub fn backtrace(&self) -> Vec<BacktraceItem> {
+        match self {
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => e.backtrace.clone(),
+        }
+    }
+
     pub(crate) fn override_source_ranges(&self, source_ranges: Vec<SourceRange>) -> Self {
         let mut new = self.clone();
         match &mut new {
-            KclError::Lexical(e) => e.source_ranges = source_ranges,
+            KclError::Lexical(e)
-            KclError::Syntax(e) => e.source_ranges = source_ranges,
+            | KclError::Syntax(e)
-            KclError::Semantic(e) => e.source_ranges = source_ranges,
+            | KclError::Semantic(e)
-            KclError::ImportCycle(e) => e.source_ranges = source_ranges,
+            | KclError::ImportCycle(e)
-            KclError::Type(e) => e.source_ranges = source_ranges,
+            | KclError::Type(e)
-            KclError::Io(e) => e.source_ranges = source_ranges,
+            | KclError::Io(e)
-            KclError::Unexpected(e) => e.source_ranges = source_ranges,
+            | KclError::Unexpected(e)
-            KclError::ValueAlreadyDefined(e) => e.source_ranges = source_ranges,
+            | KclError::ValueAlreadyDefined(e)
-            KclError::UndefinedValue(e) => e.source_ranges = source_ranges,
+            | KclError::UndefinedValue(e)
-            KclError::InvalidExpression(e) => e.source_ranges = source_ranges,
+            | KclError::InvalidExpression(e)
-            KclError::Engine(e) => e.source_ranges = source_ranges,
+            | KclError::Engine(e)
-            KclError::Internal(e) => e.source_ranges = source_ranges,
+            | KclError::Internal(e) => {
+                e.backtrace = source_ranges
+                    .iter()
+                    .map(|s| BacktraceItem {
+                        source_range: *s,
+                        fn_name: None,
+                    })
+                    .collect();
+                e.source_ranges = source_ranges;
+            }
         }
 
         new
     }
 
-    pub(crate) fn add_source_ranges(&self, source_ranges: Vec<SourceRange>) -> Self {
+    pub(crate) fn set_last_backtrace_fn_name(&self, last_fn_name: Option<String>) -> Self {
         let mut new = self.clone();
         match &mut new {
-            KclError::Lexical(e) => e.source_ranges.extend(source_ranges),
+            KclError::Lexical(e)
-            KclError::Syntax(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Syntax(e)
-            KclError::Semantic(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Semantic(e)
-            KclError::ImportCycle(e) => e.source_ranges.extend(source_ranges),
+            | KclError::ImportCycle(e)
-            KclError::Type(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Type(e)
-            KclError::Io(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Io(e)
-            KclError::Unexpected(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Unexpected(e)
-            KclError::ValueAlreadyDefined(e) => e.source_ranges.extend(source_ranges),
+            | KclError::ValueAlreadyDefined(e)
-            KclError::UndefinedValue(e) => e.source_ranges.extend(source_ranges),
+            | KclError::UndefinedValue(e)
-            KclError::InvalidExpression(e) => e.source_ranges.extend(source_ranges),
+            | KclError::InvalidExpression(e)
-            KclError::Engine(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Engine(e)
-            KclError::Internal(e) => e.source_ranges.extend(source_ranges),
+            | KclError::Internal(e) => {
+                if let Some(item) = e.backtrace.last_mut() {
+                    item.fn_name = last_fn_name;
+                }
+            }
         }
 
         new
     }
+
+    pub(crate) fn add_unwind_location(&self, last_fn_name: Option<String>, source_range: SourceRange) -> Self {
+        let mut new = self.clone();
+        match &mut new {
+            KclError::Lexical(e)
+            | KclError::Syntax(e)
+            | KclError::Semantic(e)
+            | KclError::ImportCycle(e)
+            | KclError::Type(e)
+            | KclError::Io(e)
+            | KclError::Unexpected(e)
+            | KclError::ValueAlreadyDefined(e)
+            | KclError::UndefinedValue(e)
+            | KclError::InvalidExpression(e)
+            | KclError::Engine(e)
+            | KclError::Internal(e) => {
+                if let Some(item) = e.backtrace.last_mut() {
+                    item.fn_name = last_fn_name;
+                }
+                e.backtrace.push(BacktraceItem {
+                    source_range,
+                    fn_name: None,
+                });
+                e.source_ranges.push(source_range);
+            }
+        }
+
+        new
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, ts_rs::TS, thiserror::Error, miette::Diagnostic)]
+#[serde(rename_all = "camelCase")]
+#[ts(export)]
+pub struct BacktraceItem {
+    pub source_range: SourceRange,
+    pub fn_name: Option<String>,
+}
+
+impl std::fmt::Display for BacktraceItem {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if let Some(fn_name) = &self.fn_name {
+            write!(f, "{fn_name}: {:?}", self.source_range)
+        } else {
+            write!(f, "(fn): {:?}", self.source_range)
+        }
+    }
 }
 
 impl IntoDiagnostic for KclError {
@@ -551,6 +647,7 @@ impl From<pyo3::PyErr> for KclError {
     fn from(error: pyo3::PyErr) -> Self {
         KclError::Internal(KclErrorDetails {
             source_ranges: vec![],
+            backtrace: Default::default(),
             message: error.to_string(),
         })
     }
@@ -629,8 +726,13 @@ impl CompilationError {
 
 impl From<CompilationError> for KclErrorDetails {
     fn from(err: CompilationError) -> Self {
+        let backtrace = vec![BacktraceItem {
+            source_range: err.source_range,
+            fn_name: None,
+        }];
         KclErrorDetails {
             source_ranges: vec![err.source_range],
+            backtrace,
             message: err.message,
         }
     }

rust/kcl-lib/src/execution/annotations.rs

@@ -70,10 +70,10 @@ pub(super) fn expect_properties<'a>(
 ) -> Result<&'a [Node<ObjectProperty>], KclError> {
     assert_eq!(annotation.name().unwrap(), for_key);
     Ok(&**annotation.properties.as_ref().ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: format!("Empty `{for_key}` annotation"),
+            format!("Empty `{for_key}` annotation"),
-            source_ranges: vec![annotation.as_source_range()],
+            vec![annotation.as_source_range()],
-        })
+        ))
     })?)
 }
 
@@ -84,10 +84,10 @@ pub(super) fn expect_ident(expr: &Expr) -> Result<&str, KclError> {
         }
     }
 
-    Err(KclError::Semantic(KclErrorDetails {
+    Err(KclError::Semantic(KclErrorDetails::new(
-        message: "Unexpected settings value, expected a simple name, e.g., `mm`".to_owned(),
+        "Unexpected settings value, expected a simple name, e.g., `mm`".to_owned(),
-        source_ranges: vec![expr.into()],
+        vec![expr.into()],
-    }))
+    )))
 }
 
 // Returns the unparsed number literal.
@@ -98,10 +98,10 @@ pub(super) fn expect_number(expr: &Expr) -> Result<String, KclError> {
         }
     }
 
-    Err(KclError::Semantic(KclErrorDetails {
+    Err(KclError::Semantic(KclErrorDetails::new(
-        message: "Unexpected settings value, expected a number, e.g., `1.0`".to_owned(),
+        "Unexpected settings value, expected a number, e.g., `1.0`".to_owned(),
-        source_ranges: vec![expr.into()],
+        vec![expr.into()],
-    }))
+    )))
 }
 
 pub(super) fn get_impl(annotations: &[Node<Annotation>], source_range: SourceRange) -> Result<Option<Impl>, KclError> {
@@ -113,14 +113,14 @@ pub(super) fn get_impl(annotations: &[Node<Annotation>], source_range: SourceRan
             if &*p.key.name == IMPL {
                 if let Some(s) = p.value.ident_name() {
                     return Impl::from_str(s).map(Some).map_err(|_| {
-                        KclError::Semantic(KclErrorDetails {
+                        KclError::Semantic(KclErrorDetails::new(
-                            message: format!(
+                            format!(
                                 "Invalid value for {} attribute, expected one of: {}",
                                 IMPL,
                                 IMPL_VALUES.join(", ")
                             ),
-                            source_ranges: vec![source_range],
+                            vec![source_range],
-                        })
+                        ))
                     });
                 }
             }
@@ -139,12 +139,12 @@ impl UnitLen {
             "inch" | "in" => Ok(UnitLen::Inches),
             "ft" => Ok(UnitLen::Feet),
             "yd" => Ok(UnitLen::Yards),
-            value => Err(KclError::Semantic(KclErrorDetails {
+            value => Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "Unexpected value for length units: `{value}`; expected one of `mm`, `cm`, `m`, `in`, `ft`, `yd`"
                 ),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })),
+            ))),
         }
     }
 }
@@ -154,10 +154,10 @@ impl UnitAngle {
         match s {
             "deg" => Ok(UnitAngle::Degrees),
             "rad" => Ok(UnitAngle::Radians),
-            value => Err(KclError::Semantic(KclErrorDetails {
+            value => Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("Unexpected value for angle units: `{value}`; expected one of `deg`, `rad`"),
+                format!("Unexpected value for angle units: `{value}`; expected one of `deg`, `rad`"),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })),
+            ))),
         }
     }
 }

rust/kcl-lib/src/execution/artifact.rs

@@ -941,12 +941,10 @@ fn artifacts_to_update(
         ModelingCmd::StartPath(_) => {
             let mut return_arr = Vec::new();
             let current_plane_id = path_to_plane_id_map.get(&artifact_command.cmd_id).ok_or_else(|| {
-                KclError::Internal(KclErrorDetails {
+                KclError::Internal(KclErrorDetails::new(
-                    message: format!(
+                    format!("Expected a current plane ID when processing StartPath command, but we have none: {id:?}"),
-                        "Expected a current plane ID when processing StartPath command, but we have none: {id:?}"
+                    vec![range],
-                    ),
+                ))
-                    source_ranges: vec![range],
-                })
             })?;
             return_arr.push(Artifact::Path(Path {
                 id,
@@ -1065,10 +1063,10 @@ fn artifacts_to_update(
                 // TODO: Using the first one.  Make sure to revisit this
                 // choice, don't think it matters for now.
                 path_id: ArtifactId::new(*loft_cmd.section_ids.first().ok_or_else(|| {
-                    KclError::Internal(KclErrorDetails {
+                    KclError::Internal(KclErrorDetails::new(
-                        message: format!("Expected at least one section ID in Loft command: {id:?}; cmd={cmd:?}"),
+                        format!("Expected at least one section ID in Loft command: {id:?}; cmd={cmd:?}"),
-                        source_ranges: vec![range],
+                        vec![range],
-                    })
+                    ))
                 })?),
                 surface_ids: Vec::new(),
                 edge_ids: Vec::new(),
@@ -1108,12 +1106,12 @@ fn artifacts_to_update(
                 };
                 last_path = Some(path);
                 let path_sweep_id = path.sweep_id.ok_or_else(|| {
-                    KclError::Internal(KclErrorDetails {
+                    KclError::Internal(KclErrorDetails::new(
-                        message:format!(
+                        format!(
                             "Expected a sweep ID on the path when processing Solid3dGetExtrusionFaceInfo command, but we have none: {id:?}, {path:?}"
                         ),
-                        source_ranges: vec![range],
+                        vec![range],
-                    })
+                    ))
                 })?;
                 let extra_artifact = exec_artifacts.values().find(|a| {
                     if let Artifact::StartSketchOnFace(s) = a {
@@ -1162,12 +1160,12 @@ fn artifacts_to_update(
                         continue;
                     };
                     let path_sweep_id = path.sweep_id.ok_or_else(|| {
-                        KclError::Internal(KclErrorDetails {
+                        KclError::Internal(KclErrorDetails::new(
-                            message:format!(
+                            format!(
                                 "Expected a sweep ID on the path when processing last path's Solid3dGetExtrusionFaceInfo command, but we have none: {id:?}, {path:?}"
                             ),
-                            source_ranges: vec![range],
+                            vec![range],
-                        })
+                        ))
                     })?;
                     let extra_artifact = exec_artifacts.values().find(|a| {
                         if let Artifact::StartSketchOnFace(s) = a {

rust/kcl-lib/src/execution/exec_ast.rs

@@ -86,7 +86,7 @@ impl ExecutorContext {
     ) -> Result<(Option<KclValue>, EnvironmentRef, Vec<String>), KclError> {
         crate::log::log(format!("enter module {path} {}", exec_state.stack()));
 
-        let mut local_state = ModuleState::new(path.std_path(), exec_state.stack().memory.clone(), Some(module_id));
+        let mut local_state = ModuleState::new(path.clone(), exec_state.stack().memory.clone(), Some(module_id));
         if !preserve_mem {
             std::mem::swap(&mut exec_state.mod_local, &mut local_state);
         }
@@ -131,16 +131,21 @@ impl ExecutorContext {
             match statement {
                 BodyItem::ImportStatement(import_stmt) => {
                     if !matches!(body_type, BodyType::Root) {
-                        return Err(KclError::Semantic(KclErrorDetails {
+                        return Err(KclError::Semantic(KclErrorDetails::new(
-                            message: "Imports are only supported at the top-level of a file.".to_owned(),
+                            "Imports are only supported at the top-level of a file.".to_owned(),
-                            source_ranges: vec![import_stmt.into()],
+                            vec![import_stmt.into()],
-                        }));
+                        )));
                     }
 
                     let source_range = SourceRange::from(import_stmt);
                     let attrs = &import_stmt.outer_attrs;
+                    let module_path = ModulePath::from_import_path(
+                        &import_stmt.path,
+                        &self.settings.project_directory,
+                        &exec_state.mod_local.path,
+                    )?;
                     let module_id = self
-                        .open_module(&import_stmt.path, attrs, exec_state, source_range)
+                        .open_module(&import_stmt.path, attrs, &module_path, exec_state, source_range)
                         .await?;
 
                     match &import_stmt.selector {
@@ -157,28 +162,25 @@ impl ExecutorContext {
                                 let mut ty = mem.get_from(&ty_name, env_ref, import_item.into(), 0).cloned();
 
                                 if value.is_err() && ty.is_err() {
-                                    return Err(KclError::UndefinedValue(KclErrorDetails {
+                                    return Err(KclError::UndefinedValue(KclErrorDetails::new(
-                                        message: format!("{} is not defined in module", import_item.name.name),
+                                        format!("{} is not defined in module", import_item.name.name),
-                                        source_ranges: vec![SourceRange::from(&import_item.name)],
+                                        vec![SourceRange::from(&import_item.name)],
-                                    }));
+                                    )));
                                 }
 
                                 // Check that the item is allowed to be imported (in at least one namespace).
                                 if value.is_ok() && !module_exports.contains(&import_item.name.name) {
-                                    value = Err(KclError::Semantic(KclErrorDetails {
+                                    value = Err(KclError::Semantic(KclErrorDetails::new(
-                                        message: format!(
+                                        format!(
                                             "Cannot import \"{}\" from module because it is not exported. Add \"export\" before the definition to export it.",
                                             import_item.name.name
                                         ),
-                                        source_ranges: vec![SourceRange::from(&import_item.name)],
+                                        vec![SourceRange::from(&import_item.name)],
-                                    }));
+                                    )));
                                 }
 
                                 if ty.is_ok() && !module_exports.contains(&ty_name) {
-                                    ty = Err(KclError::Semantic(KclErrorDetails {
+                                    ty = Err(KclError::Semantic(KclErrorDetails::new(String::new(), vec![])));
-                                        message: String::new(),
-                                        source_ranges: vec![],
-                                    }));
                                 }
 
                                 if value.is_err() && ty.is_err() {
@@ -225,10 +227,10 @@ impl ExecutorContext {
                                     .memory
                                     .get_from(name, env_ref, source_range, 0)
                                     .map_err(|_err| {
-                                        KclError::Internal(KclErrorDetails {
+                                        KclError::Internal(KclErrorDetails::new(
-                                            message: format!("{} is not defined in module (but was exported?)", name),
+                                            format!("{} is not defined in module (but was exported?)", name),
-                                            source_ranges: vec![source_range],
+                                            vec![source_range],
-                                        })
+                                        ))
                                     })?
                                     .clone();
                                 exec_state.mut_stack().add(name.to_owned(), item, source_range)?;
@@ -284,7 +286,14 @@ impl ExecutorContext {
 
                     // Track exports.
                     if let ItemVisibility::Export = variable_declaration.visibility {
-                        exec_state.mod_local.module_exports.push(var_name);
+                        if matches!(body_type, BodyType::Root) {
+                            exec_state.mod_local.module_exports.push(var_name);
+                        } else {
+                            exec_state.err(CompilationError::err(
+                                variable_declaration.as_source_range(),
+                                "Exports are only supported at the top-level of a file. Remove `export` or move it to the top-level.",
+                            ));
+                        }
                     }
                     // Variable declaration can be the return value of a module.
                     last_expr = matches!(body_type, BodyType::Root).then_some(value);
@@ -294,13 +303,13 @@ impl ExecutorContext {
                     let impl_kind = annotations::get_impl(&ty.outer_attrs, metadata.source_range)?.unwrap_or_default();
                     match impl_kind {
                         annotations::Impl::Rust => {
-                            let std_path = match &exec_state.mod_local.std_path {
+                            let std_path = match &exec_state.mod_local.path {
-                                Some(p) => p,
+                                ModulePath::Std { value } => value,
-                                None => {
+                                ModulePath::Local { .. } | ModulePath::Main => {
-                                    return Err(KclError::Semantic(KclErrorDetails {
+                                    return Err(KclError::Semantic(KclErrorDetails::new(
-                                        message: "User-defined types are not yet supported.".to_owned(),
+                                        "User-defined types are not yet supported.".to_owned(),
-                                        source_ranges: vec![metadata.source_range],
+                                        vec![metadata.source_range],
-                                    }));
+                                    )));
                                 }
                             };
                             let (t, props) = crate::std::std_ty(std_path, &ty.name.name);
@@ -313,10 +322,10 @@ impl ExecutorContext {
                                 .mut_stack()
                                 .add(name_in_mem.clone(), value, metadata.source_range)
                                 .map_err(|_| {
-                                    KclError::Semantic(KclErrorDetails {
+                                    KclError::Semantic(KclErrorDetails::new(
-                                        message: format!("Redefinition of type {}.", ty.name.name),
+                                        format!("Redefinition of type {}.", ty.name.name),
-                                        source_ranges: vec![metadata.source_range],
+                                        vec![metadata.source_range],
-                                    })
+                                    ))
                                 })?;
 
                             if let ItemVisibility::Export = ty.visibility {
@@ -343,10 +352,10 @@ impl ExecutorContext {
                                     .mut_stack()
                                     .add(name_in_mem.clone(), value, metadata.source_range)
                                     .map_err(|_| {
-                                        KclError::Semantic(KclErrorDetails {
+                                        KclError::Semantic(KclErrorDetails::new(
-                                            message: format!("Redefinition of type {}.", ty.name.name),
+                                            format!("Redefinition of type {}.", ty.name.name),
-                                            source_ranges: vec![metadata.source_range],
+                                            vec![metadata.source_range],
-                                        })
+                                        ))
                                     })?;
 
                                 if let ItemVisibility::Export = ty.visibility {
@@ -354,10 +363,10 @@ impl ExecutorContext {
                                 }
                             }
                             None => {
-                                return Err(KclError::Semantic(KclErrorDetails {
+                                return Err(KclError::Semantic(KclErrorDetails::new(
-                                    message: "User-defined types are not yet supported.".to_owned(),
+                                    "User-defined types are not yet supported.".to_owned(),
-                                    source_ranges: vec![metadata.source_range],
+                                    vec![metadata.source_range],
-                                }))
+                                )))
                             }
                         },
                     }
@@ -368,10 +377,10 @@ impl ExecutorContext {
                     let metadata = Metadata::from(return_statement);
 
                     if matches!(body_type, BodyType::Root) {
-                        return Err(KclError::Semantic(KclErrorDetails {
+                        return Err(KclError::Semantic(KclErrorDetails::new(
-                            message: "Cannot return from outside a function.".to_owned(),
+                            "Cannot return from outside a function.".to_owned(),
-                            source_ranges: vec![metadata.source_range],
+                            vec![metadata.source_range],
-                        }));
+                        )));
                     }
 
                     let value = self
@@ -387,10 +396,10 @@ impl ExecutorContext {
                         .mut_stack()
                         .add(memory::RETURN_NAME.to_owned(), value, metadata.source_range)
                         .map_err(|_| {
-                            KclError::Semantic(KclErrorDetails {
+                            KclError::Semantic(KclErrorDetails::new(
-                                message: "Multiple returns from a single function.".to_owned(),
+                                "Multiple returns from a single function.".to_owned(),
-                                source_ranges: vec![metadata.source_range],
+                                vec![metadata.source_range],
-                            })
+                            ))
                         })?;
                     last_expr = None;
                 }
@@ -416,16 +425,15 @@ impl ExecutorContext {
         &self,
         path: &ImportPath,
         attrs: &[Node<Annotation>],
+        resolved_path: &ModulePath,
         exec_state: &mut ExecState,
         source_range: SourceRange,
     ) -> Result<ModuleId, KclError> {
-        let resolved_path = ModulePath::from_import_path(path, &self.settings.project_directory);
-
         match path {
             ImportPath::Kcl { .. } => {
-                exec_state.global.mod_loader.cycle_check(&resolved_path, source_range)?;
+                exec_state.global.mod_loader.cycle_check(resolved_path, source_range)?;
 
-                if let Some(id) = exec_state.id_for_module(&resolved_path) {
+                if let Some(id) = exec_state.id_for_module(resolved_path) {
                     return Ok(id);
                 }
 
@@ -436,12 +444,12 @@ impl ExecutorContext {
                 exec_state.add_id_to_source(id, source.clone());
                 // TODO handle parsing errors properly
                 let parsed = crate::parsing::parse_str(&source.source, id).parse_errs_as_err()?;
-                exec_state.add_module(id, resolved_path, ModuleRepr::Kcl(parsed, None));
+                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Kcl(parsed, None));
 
                 Ok(id)
             }
             ImportPath::Foreign { .. } => {
-                if let Some(id) = exec_state.id_for_module(&resolved_path) {
+                if let Some(id) = exec_state.id_for_module(resolved_path) {
                     return Ok(id);
                 }
 
@@ -451,11 +459,11 @@ impl ExecutorContext {
                 exec_state.add_path_to_source_id(resolved_path.clone(), id);
                 let format = super::import::format_from_annotations(attrs, path, source_range)?;
                 let geom = super::import::import_foreign(path, format, exec_state, self, source_range).await?;
-                exec_state.add_module(id, resolved_path, ModuleRepr::Foreign(geom, None));
+                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Foreign(geom, None));
                 Ok(id)
             }
             ImportPath::Std { .. } => {
-                if let Some(id) = exec_state.id_for_module(&resolved_path) {
+                if let Some(id) = exec_state.id_for_module(resolved_path) {
                     return Ok(id);
                 }
 
@@ -467,7 +475,7 @@ impl ExecutorContext {
                 let parsed = crate::parsing::parse_str(&source.source, id)
                     .parse_errs_as_err()
                     .unwrap();
-                exec_state.add_module(id, resolved_path, ModuleRepr::Kcl(parsed, None));
+                exec_state.add_module(id, resolved_path.clone(), ModuleRepr::Kcl(parsed, None));
                 Ok(id)
             }
         }
@@ -493,10 +501,10 @@ impl ExecutorContext {
                     *cache = Some((val, er, items.clone()));
                     (er, items)
                 }),
-            ModuleRepr::Foreign(geom, _) => Err(KclError::Semantic(KclErrorDetails {
+            ModuleRepr::Foreign(geom, _) => Err(KclError::Semantic(KclErrorDetails::new(
-                message: "Cannot import items from foreign modules".to_owned(),
+                "Cannot import items from foreign modules".to_owned(),
-                source_ranges: vec![geom.source_range],
+                vec![geom.source_range],
-            })),
+            ))),
             ModuleRepr::Dummy => unreachable!("Looking up {}, but it is still being interpreted", path),
         };
 
@@ -572,13 +580,13 @@ impl ExecutorContext {
                 err.override_source_ranges(vec![source_range])
             } else {
                 // TODO would be great to have line/column for the underlying error here
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Error loading imported file ({path}). Open it to view more details.\n  {}",
                         err.message()
                     ),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             }
         })
     }
@@ -628,7 +636,7 @@ impl ExecutorContext {
                     .unwrap_or(false);
 
                 if rust_impl {
-                    if let Some(std_path) = &exec_state.mod_local.std_path {
+                    if let ModulePath::Std { value: std_path } = &exec_state.mod_local.path {
                         let (func, props) = crate::std::std_fn(std_path, statement_kind.expect_name());
                         KclValue::Function {
                             value: FunctionSource::Std {
@@ -639,11 +647,10 @@ impl ExecutorContext {
                             meta: vec![metadata.to_owned()],
                         }
                     } else {
-                        return Err(KclError::Semantic(KclErrorDetails {
+                        return Err(KclError::Semantic(KclErrorDetails::new(
-                            message: "Rust implementation of functions is restricted to the standard library"
+                            "Rust implementation of functions is restricted to the standard library".to_owned(),
-                                .to_owned(),
+                            vec![metadata.source_range],
-                            source_ranges: vec![metadata.source_range],
+                        )));
-                        }));
                     }
                 } else {
                     // Snapshotting memory here is crucial for semantics so that we close
@@ -667,18 +674,18 @@ impl ExecutorContext {
                         "you cannot declare variable {name} as %, because % can only be used in function calls"
                     );
 
-                    return Err(KclError::Semantic(KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
                         message,
-                        source_ranges: vec![pipe_substitution.into()],
+                        vec![pipe_substitution.into()],
-                    }));
+                    )));
                 }
                 StatementKind::Expression => match exec_state.mod_local.pipe_value.clone() {
                     Some(x) => x,
                     None => {
-                        return Err(KclError::Semantic(KclErrorDetails {
+                        return Err(KclError::Semantic(KclErrorDetails::new(
-                            message: "cannot use % outside a pipe expression".to_owned(),
+                            "cannot use % outside a pipe expression".to_owned(),
-                            source_ranges: vec![pipe_substitution.into()],
+                            vec![pipe_substitution.into()],
-                        }));
+                        )));
                     }
                 },
             },
@@ -750,13 +757,13 @@ fn apply_ascription(
         } else {
             ""
         };
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: format!(
+            format!(
-                "could not coerce {} value to type {ty}{suggestion}",
+                "could not coerce value of type {} to type {ty}{suggestion}",
                 value.human_friendly_type()
             ),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        })
+        ))
     })
 }
 
@@ -783,10 +790,10 @@ impl Node<Name> {
         ctx: &ExecutorContext,
     ) -> Result<&'a KclValue, KclError> {
         if self.abs_path {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: "Absolute paths (names beginning with `::` are not yet supported)".to_owned(),
+                "Absolute paths (names beginning with `::` are not yet supported)".to_owned(),
-                source_ranges: self.as_source_ranges(),
+                self.as_source_ranges(),
-            }));
+            )));
         }
 
         if self.path.is_empty() {
@@ -798,10 +805,10 @@ impl Node<Name> {
             let value = match mem_spec {
                 Some((env, exports)) => {
                     if !exports.contains(&p.name) {
-                        return Err(KclError::Semantic(KclErrorDetails {
+                        return Err(KclError::Semantic(KclErrorDetails::new(
-                            message: format!("Item {} not found in module's exported items", p.name),
+                            format!("Item {} not found in module's exported items", p.name),
-                            source_ranges: p.as_source_ranges(),
+                            p.as_source_ranges(),
-                        }));
+                        )));
                     }
 
                     exec_state
@@ -813,13 +820,13 @@ impl Node<Name> {
             };
 
             let KclValue::Module { value: module_id, .. } = value else {
-                return Err(KclError::Semantic(KclErrorDetails {
+                return Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Identifier in path must refer to a module, found {}",
                         value.human_friendly_type()
                     ),
-                    source_ranges: p.as_source_ranges(),
+                    p.as_source_ranges(),
-                }));
+                )));
             };
 
             mem_spec = Some(
@@ -830,10 +837,10 @@ impl Node<Name> {
 
         let (env, exports) = mem_spec.unwrap();
         if !exports.contains(&self.name.name) {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("Item {} not found in module's exported items", self.name.name),
+                format!("Item {} not found in module's exported items", self.name.name),
-                source_ranges: self.name.as_source_ranges(),
+                self.name.as_source_ranges(),
-            }));
+            )));
         }
 
         exec_state
@@ -861,46 +868,44 @@ impl Node<MemberExpression> {
                 if let Some(value) = map.get(&property) {
                     Ok(value.to_owned())
                 } else {
-                    Err(KclError::UndefinedValue(KclErrorDetails {
+                    Err(KclError::UndefinedValue(KclErrorDetails::new(
-                        message: format!("Property '{property}' not found in object"),
+                        format!("Property '{property}' not found in object"),
-                        source_ranges: vec![self.clone().into()],
+                        vec![self.clone().into()],
-                    }))
+                    )))
                 }
             }
-            (KclValue::Object { .. }, Property::String(property), true) => Err(KclError::Semantic(KclErrorDetails {
+            (KclValue::Object { .. }, Property::String(property), true) => {
-                message: format!("Cannot index object with string; use dot notation instead, e.g. `obj.{property}`"),
+                Err(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.clone().into()],
+                    format!("Cannot index object with string; use dot notation instead, e.g. `obj.{property}`"),
-            })),
+                    vec![self.clone().into()],
+                )))
+            }
             (KclValue::Object { .. }, p, _) => {
                 let t = p.type_name();
                 let article = article_for(t);
-                Err(KclError::Semantic(KclErrorDetails {
+                Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!("Only strings can be used as the property of an object, but you're using {article} {t}",),
-                        "Only strings can be used as the property of an object, but you're using {article} {t}",
+                    vec![self.clone().into()],
-                    ),
+                )))
-                    source_ranges: vec![self.clone().into()],
-                }))
             }
             (KclValue::HomArray { value: arr, .. }, Property::UInt(index), _) => {
                 let value_of_arr = arr.get(index);
                 if let Some(value) = value_of_arr {
                     Ok(value.to_owned())
                 } else {
-                    Err(KclError::UndefinedValue(KclErrorDetails {
+                    Err(KclError::UndefinedValue(KclErrorDetails::new(
-                        message: format!("The array doesn't have any item at index {index}"),
+                        format!("The array doesn't have any item at index {index}"),
-                        source_ranges: vec![self.clone().into()],
+                        vec![self.clone().into()],
-                    }))
+                    )))
                 }
             }
             (KclValue::HomArray { .. }, p, _) => {
                 let t = p.type_name();
                 let article = article_for(t);
-                Err(KclError::Semantic(KclErrorDetails {
+                Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!("Only integers >= 0 can be used as the index of an array, but you're using {article} {t}",),
-                        "Only integers >= 0 can be used as the index of an array, but you're using {article} {t}",
+                    vec![self.clone().into()],
-                    ),
+                )))
-                    source_ranges: vec![self.clone().into()],
-                }))
             }
             (KclValue::Solid { value }, Property::String(prop), false) if prop == "sketch" => Ok(KclValue::Sketch {
                 value: Box::new(value.sketch),
@@ -918,10 +923,10 @@ impl Node<MemberExpression> {
             (being_indexed, _, _) => {
                 let t = being_indexed.human_friendly_type();
                 let article = article_for(&t);
-                Err(KclError::Semantic(KclErrorDetails {
+                Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!("Only arrays can be indexed, but you're trying to index {article} {t}"),
+                    format!("Only arrays can be indexed, but you're trying to index {article} {t}"),
-                    source_ranges: vec![self.clone().into()],
+                    vec![self.clone().into()],
-                }))
+                )))
             }
         }
     }
@@ -996,26 +1001,26 @@ impl Node<BinaryExpression> {
                 meta: _,
             } = left_value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
+                return Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Cannot apply logical operator to non-boolean value: {}",
                         left_value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.left.clone().into()],
+                    vec![self.left.clone().into()],
-                }));
+                )));
             };
             let KclValue::Bool {
                 value: right_value,
                 meta: _,
             } = right_value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
+                return Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Cannot apply logical operator to non-boolean value: {}",
                         right_value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.right.clone().into()],
+                    vec![self.right.clone().into()],
-                }));
+                )));
             };
             let raw_value = match self.operator {
                 BinaryOperator::Or => left_value || right_value,
@@ -1115,13 +1120,13 @@ impl Node<UnaryExpression> {
                 meta: _,
             } = value
             else {
-                return Err(KclError::Semantic(KclErrorDetails {
+                return Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Cannot apply unary operator ! to non-boolean value: {}",
                         value.human_friendly_type()
                     ),
-                    source_ranges: vec![self.into()],
+                    vec![self.into()],
-                }));
+                )));
             };
             let meta = vec![Metadata {
                 source_range: self.into(),
@@ -1136,13 +1141,13 @@ impl Node<UnaryExpression> {
 
         let value = &self.argument.get_result(exec_state, ctx).await?;
         let err = || {
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "You can only negate numbers, planes, or lines, but this is a {}",
                     value.human_friendly_type()
                 ),
-                source_ranges: vec![self.into()],
+                vec![self.into()],
-            })
+            ))
         };
         match value {
             KclValue::Number { value, ty, .. } => {
@@ -1239,10 +1244,10 @@ pub(crate) async fn execute_pipe_body(
     ctx: &ExecutorContext,
 ) -> Result<KclValue, KclError> {
     let Some((first, body)) = body.split_first() else {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: "Pipe expressions cannot be empty".to_owned(),
+            "Pipe expressions cannot be empty".to_owned(),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }));
+        )));
     };
     // Evaluate the first element in the pipeline.
     // They use the pipe_value from some AST node above this, so that if pipe expression is nested in a larger pipe expression,
@@ -1277,10 +1282,10 @@ async fn inner_execute_pipe_body(
 ) -> Result<KclValue, KclError> {
     for expression in body {
         if let Expr::TagDeclarator(_) = expression {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("This cannot be in a PipeExpression: {:?}", expression),
+                format!("This cannot be in a PipeExpression: {:?}", expression),
-                source_ranges: vec![expression.into()],
+                vec![expression.into()],
-            }));
+            )));
         }
         let metadata = Metadata {
             source_range: SourceRange::from(expression),
@@ -1349,35 +1354,37 @@ impl Node<ArrayRangeExpression> {
                 StatementKind::Expression,
             )
             .await?;
-        let (start, start_ty) = start_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails {
+        let (start, start_ty) = start_val
-            source_ranges: vec![self.into()],
+            .as_int_with_ty()
-            message: format!("Expected int but found {}", start_val.human_friendly_type()),
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
-        }))?;
+                format!("Expected int but found {}", start_val.human_friendly_type()),
+                vec![self.into()],
+            )))?;
         let metadata = Metadata::from(&self.end_element);
         let end_val = ctx
             .execute_expr(&self.end_element, exec_state, &metadata, &[], StatementKind::Expression)
             .await?;
-        let (end, end_ty) = end_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails {
+        let (end, end_ty) = end_val.as_int_with_ty().ok_or(KclError::Semantic(KclErrorDetails::new(
-            source_ranges: vec![self.into()],
+            format!("Expected int but found {}", end_val.human_friendly_type()),
-            message: format!("Expected int but found {}", end_val.human_friendly_type()),
+            vec![self.into()],
-        }))?;
+        )))?;
 
         if start_ty != end_ty {
             let start = start_val.as_ty_f64().unwrap_or(TyF64 { n: 0.0, ty: start_ty });
             let start = fmt::human_display_number(start.n, start.ty);
             let end = end_val.as_ty_f64().unwrap_or(TyF64 { n: 0.0, ty: end_ty });
             let end = fmt::human_display_number(end.n, end.ty);
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.into()],
+                format!("Range start and end must be of the same type, but found {start} and {end}"),
-                message: format!("Range start and end must be of the same type, but found {start} and {end}"),
+                vec![self.into()],
-            }));
+            )));
         }
 
         if end < start {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.into()],
+                format!("Range start is greater than range end: {start} .. {end}"),
-                message: format!("Range start is greater than range end: {start} .. {end}"),
+                vec![self.into()],
-            }));
+            )));
         }
 
         let range: Vec<_> = if self.end_inclusive {
@@ -1438,10 +1445,10 @@ fn article_for<S: AsRef<str>>(s: S) -> &'static str {
 fn number_as_f64(v: &KclValue, source_range: SourceRange) -> Result<TyF64, KclError> {
     v.as_ty_f64().ok_or_else(|| {
         let actual_type = v.human_friendly_type();
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            source_ranges: vec![source_range],
+            format!("Expected a number, but found {actual_type}",),
-            message: format!("Expected a number, but found {actual_type}",),
+            vec![source_range],
-        })
+        ))
     })
 }
 
@@ -1530,16 +1537,16 @@ impl Property {
                         if let Some(x) = crate::try_f64_to_usize(value) {
                             Ok(Property::UInt(x))
                         } else {
-                            Err(KclError::Semantic(KclErrorDetails {
+                            Err(KclError::Semantic(KclErrorDetails::new(
-                                source_ranges: property_sr,
+                                format!("{value} is not a valid index, indices must be whole numbers >= 0"),
-                                message: format!("{value} is not a valid index, indices must be whole numbers >= 0"),
+                                property_sr,
-                            }))
+                            )))
                         }
                     }
-                    _ => Err(KclError::Semantic(KclErrorDetails {
+                    _ => Err(KclError::Semantic(KclErrorDetails::new(
-                        source_ranges: vec![sr],
+                        "Only numbers (>= 0) can be indexes".to_owned(),
-                        message: "Only numbers (>= 0) can be indexes".to_owned(),
+                        vec![sr],
-                    })),
+                    ))),
                 }
             }
         }
@@ -1547,12 +1554,7 @@ impl Property {
 }
 
 fn jvalue_to_prop(value: &KclValue, property_sr: Vec<SourceRange>, name: &str) -> Result<Property, KclError> {
-    let make_err = |message: String| {
+    let make_err = |message: String| Err::<Property, _>(KclError::Semantic(KclErrorDetails::new(message, property_sr)));
-        Err::<Property, _>(KclError::Semantic(KclErrorDetails {
-            source_ranges: property_sr,
-            message,
-        }))
-    };
     match value {
         KclValue::Number{value: num, .. } => {
             let num = *num;
@@ -1650,7 +1652,7 @@ a = 42: string
         let err = result.unwrap_err();
         assert!(
             err.to_string()
-                .contains("could not coerce number(default units) value to type string"),
+                .contains("could not coerce value of type number(default units) to type string"),
             "Expected error but found {err:?}"
         );
 
@@ -1661,7 +1663,7 @@ a = 42: Plane
         let err = result.unwrap_err();
         assert!(
             err.to_string()
-                .contains("could not coerce number(default units) value to type Plane"),
+                .contains("could not coerce value of type number(default units) to type Plane"),
             "Expected error but found {err:?}"
         );
 
@@ -1671,8 +1673,9 @@ arr = [0]: [string]
         let result = parse_execute(program).await;
         let err = result.unwrap_err();
         assert!(
-            err.to_string()
+            err.to_string().contains(
-                .contains("could not coerce [any; 1] value to type [string]"),
+                "could not coerce value of type array of number(default units) with 1 value to type [string]"
+            ),
             "Expected error but found {err:?}"
         );
 
@@ -1683,7 +1686,7 @@ mixedArr = [0, "a"]: [number(mm)]
         let err = result.unwrap_err();
         assert!(
             err.to_string()
-                .contains("could not coerce [any; 2] value to type [number(mm)]"),
+                .contains("could not coerce value of type array of number(default units), string with 2 values to type [number(mm)]"),
             "Expected error but found {err:?}"
         );
     }
@@ -1795,10 +1798,10 @@ d = b + c
                 crate::engine::conn_mock::EngineConnection::new()
                     .await
                     .map_err(|err| {
-                        KclError::Internal(crate::errors::KclErrorDetails {
+                        KclError::Internal(KclErrorDetails::new(
-                            message: format!("Failed to create mock engine connection: {}", err),
+                            format!("Failed to create mock engine connection: {}", err),
-                            source_ranges: vec![SourceRange::default()],
+                            vec![SourceRange::default()],
-                        })
+                        ))
                     })
                     .unwrap(),
             )),

rust/kcl-lib/src/execution/fn_call.rs

@@ -1,13 +1,16 @@
 use async_recursion::async_recursion;
 use indexmap::IndexMap;
 
-use crate::execution::cad_op::{Group, OpArg, OpKclValue, Operation};
+use super::{types::ArrayLen, EnvironmentRef};
 use crate::{
     docs::StdLibFn,
     errors::{KclError, KclErrorDetails},
     execution::{
-        kcl_value::FunctionSource, memory, types::RuntimeType, BodyType, ExecState, ExecutorContext, KclValue,
+        cad_op::{Group, OpArg, OpKclValue, Operation},
-        Metadata, StatementKind, TagEngineInfo, TagIdentifier,
+        kcl_value::FunctionSource,
+        memory,
+        types::RuntimeType,
+        BodyType, ExecState, ExecutorContext, KclValue, Metadata, StatementKind, TagEngineInfo, TagIdentifier,
     },
     parsing::ast::types::{CallExpressionKw, DefaultParamVal, FunctionExpression, Node, Program, Type},
     source_range::SourceRange,
@@ -15,9 +18,6 @@ use crate::{
     CompilationError,
 };
 
-use super::types::ArrayLen;
-use super::EnvironmentRef;
-
 #[derive(Debug, Clone)]
 pub struct Args {
     /// Positional args.
@@ -281,6 +281,13 @@ impl Node<CallExpressionKw> {
                 def.call_kw(Some(func.name()), exec_state, ctx, args, callsite)
                     .await
                     .map(Option::unwrap)
+                    .map_err(|e| {
+                        // This is used for the backtrace display.  We don't add
+                        // another location the way we do for user-defined
+                        // functions because the error uses the Args, which
+                        // already points here.
+                        e.set_last_backtrace_fn_name(Some(func.name()))
+                    })
             }
             None => {
                 // Clone the function so that we can use a mutable reference to
@@ -288,10 +295,10 @@ impl Node<CallExpressionKw> {
                 let func = fn_name.get_result(exec_state, ctx).await?.clone();
 
                 let Some(fn_src) = func.as_fn() else {
-                    return Err(KclError::Semantic(KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
-                        message: "cannot call this because it isn't a function".to_string(),
+                        "cannot call this because it isn't a function".to_string(),
-                        source_ranges: vec![callsite],
+                        vec![callsite],
-                    }));
+                    )));
                 };
 
                 let return_value = fn_src
@@ -299,7 +306,10 @@ impl Node<CallExpressionKw> {
                     .await
                     .map_err(|e| {
                         // Add the call expression to the source ranges.
-                        e.add_source_ranges(vec![callsite])
+                        //
+                        // TODO: Use the name that the function was defined
+                        // with, not the identifier it was used with.
+                        e.add_unwind_location(Some(fn_name.name.name.clone()), callsite)
                     })?;
 
                 let result = return_value.ok_or_else(move || {
@@ -308,10 +318,10 @@ impl Node<CallExpressionKw> {
                     if let KclValue::Function { meta, .. } = func {
                         source_ranges = meta.iter().map(|m| m.source_range).collect();
                     };
-                    KclError::UndefinedValue(KclErrorDetails {
+                    KclError::UndefinedValue(KclErrorDetails::new(
-                        message: format!("Result of user-defined function {} is undefined", fn_name),
+                        format!("Result of user-defined function {} is undefined", fn_name),
                         source_ranges,
-                    })
+                    ))
                 })?;
 
                 Ok(result)
@@ -490,10 +500,10 @@ fn update_memory_for_tags_of_geometry(result: &mut KclValue, exec_state: &mut Ex
                     let tag_id = if let Some(t) = value.sketch.tags.get(&tag.name) {
                         let mut t = t.clone();
                         let Some(info) = t.get_cur_info() else {
-                            return Err(KclError::Internal(KclErrorDetails {
+                            return Err(KclError::Internal(KclErrorDetails::new(
-                                message: format!("Tag {} does not have path info", tag.name),
+                                format!("Tag {} does not have path info", tag.name),
-                                source_ranges: vec![tag.into()],
+                                vec![tag.into()],
-                            }));
+                            )));
                         };
 
                         let mut info = info.clone();
@@ -608,10 +618,10 @@ fn type_check_params_kw(
                                 // TODO if we have access to the AST for the argument we could choose which example to suggest.
                                 message = format!("{message}\n\nYou may need to add information about the type of the argument, for example:\n  using a numeric suffix: `42{ty}`\n  or using type ascription: `foo(): number({ty})`");
                             }
-                            KclError::Semantic(KclErrorDetails {
+                            KclError::Semantic(KclErrorDetails::new(
                                 message,
-                                source_ranges: vec![arg.source_range],
+                                vec![arg.source_range],
-                            })
+                            ))
                         })?;
                 }
             }
@@ -673,8 +683,8 @@ fn type_check_params_kw(
                     exec_state,
                 )
                 .map_err(|_| {
-                    KclError::Semantic(KclErrorDetails {
+                    KclError::Semantic(KclErrorDetails::new(
-                        message: format!(
+                        format!(
                             "The input argument of {} requires a value with type `{}`, but found {}",
                             fn_name
                                 .map(|n| format!("`{}`", n))
@@ -682,8 +692,8 @@ fn type_check_params_kw(
                             ty,
                             arg.1.value.human_friendly_type()
                         ),
-                        source_ranges: vec![arg.1.source_range],
+                        vec![arg.1.source_range],
-                    })
+                    ))
                 })?;
         }
     } else if let Some((name, _)) = &fn_def.input_arg {
@@ -730,13 +740,13 @@ fn assign_args_to_params_kw(
                         .add(name.clone(), value, default_val.source_range())?;
                 }
                 None => {
-                    return Err(KclError::Semantic(KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
-                        source_ranges,
+                        format!(
-                        message: format!(
                             "This function requires a parameter {}, but you haven't passed it one.",
                             name
                         ),
-                    }));
+                        source_ranges,
+                    )));
                 }
             },
         }
@@ -747,16 +757,15 @@ fn assign_args_to_params_kw(
 
         let Some(unlabeled) = unlabelled else {
             return Err(if args.kw_args.labeled.contains_key(param_name) {
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
+                    format!("The function does declare a parameter named '{param_name}', but this parameter doesn't use a label. Try removing the `{param_name}:`"),
                     source_ranges,
-                    message: format!("The function does declare a parameter named '{param_name}', but this parameter doesn't use a label. Try removing the `{param_name}:`"),
+                ))
-                })
             } else {
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
+                    "This function expects an unlabeled first parameter, but you haven't passed it one.".to_owned(),
                     source_ranges,
-                    message: "This function expects an unlabeled first parameter, but you haven't passed it one."
+                ))
-                        .to_owned(),
-                })
             });
         };
         exec_state.mut_stack().add(
@@ -789,14 +798,14 @@ fn coerce_result_type(
                 ty = RuntimeType::Union(vec![(**inner).clone(), ty]);
             }
             let val = val.coerce(&ty, exec_state).map_err(|_| {
-                KclError::Semantic(KclErrorDetails {
+                KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "This function requires its result to be of type `{}`, but found {}",
                         ty.human_friendly_type(),
                         val.human_friendly_type(),
                     ),
-                    source_ranges: ret_ty.as_source_ranges(),
+                    ret_ty.as_source_ranges(),
-                })
+                ))
             })?;
             Ok(Some(val))
         } else {
@@ -873,10 +882,10 @@ mod test {
                 "all params required, none given, should error",
                 vec![req_param("x")],
                 vec![],
-                Err(KclError::Semantic(KclErrorDetails {
+                Err(KclError::Semantic(KclErrorDetails::new(
-                    source_ranges: vec![SourceRange::default()],
+                    "This function requires a parameter x, but you haven't passed it one.".to_owned(),
-                    message: "This function requires a parameter x, but you haven't passed it one.".to_owned(),
+                    vec![SourceRange::default()],
-                })),
+                ))),
             ),
             (
                 "all params optional, none given, should be OK",
@@ -888,10 +897,10 @@ mod test {
                 "mixed params, too few given",
                 vec![req_param("x"), opt_param("y")],
                 vec![],
-                Err(KclError::Semantic(KclErrorDetails {
+                Err(KclError::Semantic(KclErrorDetails::new(
-                    source_ranges: vec![SourceRange::default()],
+                    "This function requires a parameter x, but you haven't passed it one.".to_owned(),
-                    message: "This function requires a parameter x, but you haven't passed it one.".to_owned(),
+                    vec![SourceRange::default()],
-                })),
+                ))),
             ),
             (
                 "mixed params, minimum given, should be OK",

rust/kcl-lib/src/execution/geometry.rs

@@ -469,18 +469,18 @@ impl TryFrom<PlaneData> for PlaneInfo {
             PlaneData::NegYZ => PlaneName::NegYz,
             PlaneData::Plane(_) => {
                 // We will never get here since we already checked for PlaneData::Plane.
-                return Err(KclError::Internal(KclErrorDetails {
+                return Err(KclError::Internal(KclErrorDetails::new(
-                    message: format!("PlaneData {:?} not found", value),
+                    format!("PlaneData {:?} not found", value),
-                    source_ranges: Default::default(),
+                    Default::default(),
-                }));
+                )));
             }
         };
 
         let info = DEFAULT_PLANE_INFO.get(&name).ok_or_else(|| {
-            KclError::Internal(KclErrorDetails {
+            KclError::Internal(KclErrorDetails::new(
-                message: format!("Plane {} not found", name),
+                format!("Plane {} not found", name),
-                source_ranges: Default::default(),
+                Default::default(),
-            })
+            ))
         })?;
 
         Ok(info.clone())

rust/kcl-lib/src/execution/import.rs

@@ -37,53 +37,43 @@ pub async fn import_foreign(
 ) -> Result<PreImportedGeometry, KclError> {
     // Make sure the file exists.
     if !ctxt.fs.exists(file_path, source_range).await? {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: format!("File `{}` does not exist.", file_path.display()),
+            format!("File `{}` does not exist.", file_path.display()),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }));
+        )));
     }
 
     let ext_format = get_import_format_from_extension(file_path.extension().ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: format!("No file extension found for `{}`", file_path.display()),
+            format!("No file extension found for `{}`", file_path.display()),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        })
+        ))
     })?)
-    .map_err(|e| {
+    .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
-        KclError::Semantic(KclErrorDetails {
-            message: e.to_string(),
-            source_ranges: vec![source_range],
-        })
-    })?;
 
     // Get the format type from the extension of the file.
     let format = if let Some(format) = format {
         // Validate the given format with the extension format.
-        validate_extension_format(ext_format, format.clone()).map_err(|e| {
+        validate_extension_format(ext_format, format.clone())
-            KclError::Semantic(KclErrorDetails {
+            .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
-                message: e.to_string(),
-                source_ranges: vec![source_range],
-            })
-        })?;
         format
     } else {
         ext_format
     };
 
     // Get the file contents for each file path.
-    let file_contents = ctxt.fs.read(file_path, source_range).await.map_err(|e| {
+    let file_contents = ctxt
-        KclError::Semantic(KclErrorDetails {
+        .fs
-            message: e.to_string(),
+        .read(file_path, source_range)
-            source_ranges: vec![source_range],
+        .await
-        })
+        .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
-    })?;
 
     // We want the file_path to be without the parent.
     let file_name = file_path.file_name().map(|p| p.to_string()).ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: format!("Could not get the file name from the path `{}`", file_path.display()),
+            format!("Could not get the file name from the path `{}`", file_path.display()),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        })
+        ))
     })?;
     let mut import_files = vec![kcmc::ImportFile {
         path: file_name.to_string(),
@@ -96,12 +86,8 @@ pub async fn import_foreign(
         // Check if the file is a binary gltf file, in that case we don't need to import the bin
         // file.
         if !file_contents.starts_with(b"glTF") {
-            let json = gltf_json::Root::from_slice(&file_contents).map_err(|e| {
+            let json = gltf_json::Root::from_slice(&file_contents)
-                KclError::Semantic(KclErrorDetails {
+                .map_err(|e| KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
-                    message: e.to_string(),
-                    source_ranges: vec![source_range],
-                })
-            })?;
 
             // Read the gltf file and check if there is a bin file.
             for buffer in json.buffers.iter() {
@@ -109,18 +95,16 @@ pub async fn import_foreign(
                     if !uri.starts_with("data:") {
                         // We want this path relative to the file_path given.
                         let bin_path = file_path.parent().map(|p| p.join(uri)).ok_or_else(|| {
-                            KclError::Semantic(KclErrorDetails {
+                            KclError::Semantic(KclErrorDetails::new(
-                                message: format!("Could not get the parent path of the file `{}`", file_path.display()),
+                                format!("Could not get the parent path of the file `{}`", file_path.display()),
-                                source_ranges: vec![source_range],
+                                vec![source_range],
-                            })
+                            ))
                         })?;
 
-                        let bin_contents = ctxt.fs.read(&bin_path, source_range).await.map_err(|e| {
+                        let bin_contents =
-                            KclError::Semantic(KclErrorDetails {
+                            ctxt.fs.read(&bin_path, source_range).await.map_err(|e| {
-                                message: e.to_string(),
+                                KclError::Semantic(KclErrorDetails::new(e.to_string(), vec![source_range]))
-                                source_ranges: vec![source_range],
+                            })?;
-                            })
-                        })?;
 
                         import_files.push(ImportFile {
                             path: uri.to_string(),
@@ -157,13 +141,13 @@ pub(super) fn format_from_annotations(
         if p.key.name == annotations::IMPORT_FORMAT {
             result = Some(
                 get_import_format_from_extension(annotations::expect_ident(&p.value)?).map_err(|_| {
-                    KclError::Semantic(KclErrorDetails {
+                    KclError::Semantic(KclErrorDetails::new(
-                        message: format!(
+                        format!(
                             "Unknown format for import, expected one of: {}",
                             crate::IMPORT_FILE_EXTENSIONS.join(", ")
                         ),
-                        source_ranges: vec![p.as_source_range()],
+                        vec![p.as_source_range()],
-                    })
+                    ))
                 })?,
             );
             break;
@@ -175,10 +159,10 @@ pub(super) fn format_from_annotations(
             path.extension()
                 .and_then(|ext| get_import_format_from_extension(ext).ok())
         })
-        .ok_or(KclError::Semantic(KclErrorDetails {
+        .ok_or(KclError::Semantic(KclErrorDetails::new(
-            message: "Unknown or missing extension, and no specified format for imported file".to_owned(),
+            "Unknown or missing extension, and no specified format for imported file".to_owned(),
-            source_ranges: vec![import_source_range],
+            vec![import_source_range],
-        }))?;
+        )))?;
 
     for p in props {
         match p.key.name.as_str() {
@@ -190,15 +174,15 @@ pub(super) fn format_from_annotations(
             }
             annotations::IMPORT_FORMAT => {}
             _ => {
-                return Err(KclError::Semantic(KclErrorDetails {
+                return Err(KclError::Semantic(KclErrorDetails::new(
-                    message: format!(
+                    format!(
                         "Unexpected annotation for import, expected one of: {}, {}, {}",
                         annotations::IMPORT_FORMAT,
                         annotations::IMPORT_COORDS,
                         annotations::IMPORT_LENGTH_UNIT
                     ),
-                    source_ranges: vec![p.as_source_range()],
+                    vec![p.as_source_range()],
-                }))
+                )))
             }
         }
     }
@@ -215,8 +199,8 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
     }
 
     let Some(coords) = coords else {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "Unknown coordinate system: {coords_str}, expected one of: {}",
                 annotations::IMPORT_COORDS_VALUES
                     .iter()
@@ -224,8 +208,8 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
                     .collect::<Vec<_>>()
                     .join(", ")
             ),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }));
+        )));
     };
 
     match fmt {
@@ -233,13 +217,13 @@ fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRan
         InputFormat3d::Ply(opts) => opts.coords = coords,
         InputFormat3d::Stl(opts) => opts.coords = coords,
         _ => {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "`{}` option cannot be applied to the specified format",
                     annotations::IMPORT_COORDS
                 ),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            }))
+            )))
         }
     }
 
@@ -254,13 +238,13 @@ fn set_length_unit(fmt: &mut InputFormat3d, units_str: &str, source_range: Sourc
         InputFormat3d::Ply(opts) => opts.units = units.into(),
         InputFormat3d::Stl(opts) => opts.units = units.into(),
         _ => {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "`{}` option cannot be applied to the specified format",
                     annotations::IMPORT_LENGTH_UNIT
                 ),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            }))
+            )))
         }
     }
 

rust/kcl-lib/src/execution/kcl_value.rs

@@ -281,8 +281,34 @@ impl KclValue {
     /// Human readable type name used in error messages.  Should not be relied
     /// on for program logic.
     pub(crate) fn human_friendly_type(&self) -> String {
-        if let Some(t) = self.principal_type() {
+        self.inner_human_friendly_type(1)
-            return t.to_string();
+    }
+
+    fn inner_human_friendly_type(&self, max_depth: usize) -> String {
+        if let Some(pt) = self.principal_type() {
+            if max_depth > 0 {
+                // The principal type of an array uses the array's element type,
+                // which is oftentimes `any`, and that's not a helpful message. So
+                // we show the actual elements.
+                if let Some(elements) = self.as_array() {
+                    // If it's empty, we want to show the type of the array.
+                    if !elements.is_empty() {
+                        // A max of 3 is good because it's common to use 3D points.
+                        let max = 3;
+                        let len = elements.len();
+                        let ellipsis = if len > max { ", ..." } else { "" };
+                        let element_label = if len == 1 { "value" } else { "values" };
+                        let element_tys = elements
+                            .iter()
+                            .take(max)
+                            .map(|elem| elem.inner_human_friendly_type(max_depth - 1))
+                            .collect::<Vec<_>>()
+                            .join(", ");
+                        return format!("array of {element_tys}{ellipsis} with {len} {element_label}");
+                    }
+                }
+            }
+            return pt.to_string();
         }
         match self {
             KclValue::Uuid { .. } => "Unique ID (uuid)",
@@ -543,17 +569,13 @@ impl KclValue {
     /// If this value fits in a u32, return it.
     pub fn get_u32(&self, source_ranges: Vec<SourceRange>) -> Result<u32, KclError> {
         let u = self.as_int().and_then(|n| u64::try_from(n).ok()).ok_or_else(|| {
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(
-                message: "Expected an integer >= 0".to_owned(),
+                "Expected an integer >= 0".to_owned(),
-                source_ranges: source_ranges.clone(),
+                source_ranges.clone(),
-            })
+            ))
         })?;
-        u32::try_from(u).map_err(|_| {
+        u32::try_from(u)
-            KclError::Semantic(KclErrorDetails {
+            .map_err(|_| KclError::Semantic(KclErrorDetails::new("Number was too big".to_owned(), source_ranges)))
-                message: "Number was too big".to_owned(),
-                source_ranges,
-            })
-        })
     }
 
     /// If this value is of type function, return it.
@@ -568,10 +590,10 @@ impl KclValue {
     pub fn get_tag_identifier(&self) -> Result<TagIdentifier, KclError> {
         match self {
             KclValue::TagIdentifier(t) => Ok(*t.clone()),
-            _ => Err(KclError::Semantic(KclErrorDetails {
+            _ => Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("Not a tag identifier: {:?}", self),
+                format!("Not a tag identifier: {:?}", self),
-                source_ranges: self.clone().into(),
+                self.clone().into(),
-            })),
+            ))),
         }
     }
 
@@ -579,20 +601,20 @@ impl KclValue {
     pub fn get_tag_declarator(&self) -> Result<TagNode, KclError> {
         match self {
             KclValue::TagDeclarator(t) => Ok((**t).clone()),
-            _ => Err(KclError::Semantic(KclErrorDetails {
+            _ => Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("Not a tag declarator: {:?}", self),
+                format!("Not a tag declarator: {:?}", self),
-                source_ranges: self.clone().into(),
+                self.clone().into(),
-            })),
+            ))),
         }
     }
 
     /// If this KCL value is a bool, retrieve it.
     pub fn get_bool(&self) -> Result<bool, KclError> {
         let Self::Bool { value: b, .. } = self else {
-            return Err(KclError::Type(KclErrorDetails {
+            return Err(KclError::Type(KclErrorDetails::new(
-                source_ranges: self.into(),
+                format!("Expected bool, found {}", self.human_friendly_type()),
-                message: format!("Expected bool, found {}", self.human_friendly_type()),
+                self.into(),
-            }));
+            )));
         };
         Ok(*b)
     }
@@ -648,3 +670,88 @@ impl From<GeometryWithImportedGeometry> for KclValue {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_human_friendly_type() {
+        let len = KclValue::Number {
+            value: 1.0,
+            ty: NumericType::Known(UnitType::Length(UnitLen::Unknown)),
+            meta: vec![],
+        };
+        assert_eq!(len.human_friendly_type(), "number(Length)".to_string());
+
+        let unknown = KclValue::Number {
+            value: 1.0,
+            ty: NumericType::Unknown,
+            meta: vec![],
+        };
+        assert_eq!(unknown.human_friendly_type(), "number(unknown units)".to_string());
+
+        let mm = KclValue::Number {
+            value: 1.0,
+            ty: NumericType::Known(UnitType::Length(UnitLen::Mm)),
+            meta: vec![],
+        };
+        assert_eq!(mm.human_friendly_type(), "number(mm)".to_string());
+
+        let array1_mm = KclValue::HomArray {
+            value: vec![mm.clone()],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(
+            array1_mm.human_friendly_type(),
+            "array of number(mm) with 1 value".to_string()
+        );
+
+        let array2_mm = KclValue::HomArray {
+            value: vec![mm.clone(), mm.clone()],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(
+            array2_mm.human_friendly_type(),
+            "array of number(mm), number(mm) with 2 values".to_string()
+        );
+
+        let array3_mm = KclValue::HomArray {
+            value: vec![mm.clone(), mm.clone(), mm.clone()],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(
+            array3_mm.human_friendly_type(),
+            "array of number(mm), number(mm), number(mm) with 3 values".to_string()
+        );
+
+        let inches = KclValue::Number {
+            value: 1.0,
+            ty: NumericType::Known(UnitType::Length(UnitLen::Inches)),
+            meta: vec![],
+        };
+        let array4 = KclValue::HomArray {
+            value: vec![mm.clone(), mm.clone(), inches.clone(), mm.clone()],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(
+            array4.human_friendly_type(),
+            "array of number(mm), number(mm), number(in), ... with 4 values".to_string()
+        );
+
+        let empty_array = KclValue::HomArray {
+            value: vec![],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(empty_array.human_friendly_type(), "[any; 0]".to_string());
+
+        let array_nested = KclValue::HomArray {
+            value: vec![array2_mm.clone()],
+            ty: RuntimeType::any(),
+        };
+        assert_eq!(
+            array_nested.human_friendly_type(),
+            "array of [any; 2] with 1 value".to_string()
+        );
+    }
+}

rust/kcl-lib/src/execution/memory.rs

@@ -364,10 +364,10 @@ impl ProgramMemory {
             };
         }
 
-        Err(KclError::UndefinedValue(KclErrorDetails {
+        Err(KclError::UndefinedValue(KclErrorDetails::new(
-            message: format!("`{}` is not defined", var),
+            format!("`{}` is not defined", var),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        }))
+        )))
     }
 
     /// Iterate over all key/value pairs in the specified environment which satisfy the provided
@@ -485,10 +485,10 @@ impl ProgramMemory {
             };
         }
 
-        Err(KclError::UndefinedValue(KclErrorDetails {
+        Err(KclError::UndefinedValue(KclErrorDetails::new(
-            message: format!("`{}` is not defined", var),
+            format!("`{}` is not defined", var),
-            source_ranges: vec![],
+            vec![],
-        }))
+        )))
     }
 }
 
@@ -643,10 +643,10 @@ impl Stack {
     pub fn add(&mut self, key: String, value: KclValue, source_range: SourceRange) -> Result<(), KclError> {
         let env = self.memory.get_env(self.current_env.index());
         if env.contains_key(&key) {
-            return Err(KclError::ValueAlreadyDefined(KclErrorDetails {
+            return Err(KclError::ValueAlreadyDefined(KclErrorDetails::new(
-                message: format!("Cannot redefine `{}`", key),
+                format!("Cannot redefine `{}`", key),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            }));
+            )));
         }
 
         self.memory.stats.mutation_count.fetch_add(1, Ordering::Relaxed);

rust/kcl-lib/src/execution/mod.rs

@@ -858,10 +858,9 @@ impl ExecutorContext {
 
             for module in modules {
                 let Some((import_stmt, module_id, module_path, repr)) = universe.get(&module) else {
-                    return Err(KclErrorWithOutputs::no_outputs(KclError::Internal(KclErrorDetails {
+                    return Err(KclErrorWithOutputs::no_outputs(KclError::Internal(
-                        message: format!("Module {module} not found in universe"),
+                        KclErrorDetails::new(format!("Module {module} not found in universe"), Default::default()),
-                        source_ranges: Default::default(),
+                    )));
-                    })));
                 };
                 let module_id = *module_id;
                 let module_path = module_path.clone();
@@ -921,10 +920,10 @@ impl ExecutorContext {
 
                             result.map(|val| ModuleRepr::Foreign(geom.clone(), val))
                         }
-                        ModuleRepr::Dummy | ModuleRepr::Root => Err(KclError::Internal(KclErrorDetails {
+                        ModuleRepr::Dummy | ModuleRepr::Root => Err(KclError::Internal(KclErrorDetails::new(
-                            message: format!("Module {module_path} not found in universe"),
+                            format!("Module {module_path} not found in universe"),
-                            source_ranges: vec![source_range],
+                            vec![source_range],
-                        })),
+                        ))),
                     }
                 };
 
@@ -1045,6 +1044,7 @@ impl ExecutorContext {
 
         let root_imports = crate::walk::import_universe(
             self,
+            &ModulePath::Main,
             &ModuleRepr::Kcl(program.ast.clone(), None),
             &mut universe,
             exec_state,
@@ -1212,15 +1212,10 @@ impl ExecutorContext {
     /// SAFETY: the current thread must have sole access to the memory referenced in exec_state.
     async fn eval_prelude(&self, exec_state: &mut ExecState, source_range: SourceRange) -> Result<(), KclError> {
         if exec_state.stack().memory.requires_std() {
+            let path = vec!["std".to_owned(), "prelude".to_owned()];
+            let resolved_path = ModulePath::from_std_import_path(&path)?;
             let id = self
-                .open_module(
+                .open_module(&ImportPath::Std { path }, &[], &resolved_path, exec_state, source_range)
-                    &ImportPath::Std {
-                        path: vec!["std".to_owned(), "prelude".to_owned()],
-                    },
-                    &[],
-                    exec_state,
-                    source_range,
-                )
                 .await?;
             let (module_memory, _) = self.exec_module_for_items(id, exec_state, source_range).await?;
 
@@ -1288,10 +1283,10 @@ impl ExecutorContext {
             .await?;
 
         let kittycad_modeling_cmds::websocket::OkWebSocketResponseData::Export { files } = resp else {
-            return Err(KclError::Internal(crate::errors::KclErrorDetails {
+            return Err(KclError::Internal(crate::errors::KclErrorDetails::new(
-                message: format!("Expected Export response, got {resp:?}",),
+                format!("Expected Export response, got {resp:?}",),
-                source_ranges: vec![SourceRange::default()],
+                vec![SourceRange::default()],
-            }));
+            )));
         };
 
         Ok(files)
@@ -1308,10 +1303,10 @@ impl ExecutorContext {
                     coords: *kittycad_modeling_cmds::coord::KITTYCAD,
                     created: if deterministic_time {
                         Some("2021-01-01T00:00:00Z".parse().map_err(|e| {
-                            KclError::Internal(crate::errors::KclErrorDetails {
+                            KclError::Internal(crate::errors::KclErrorDetails::new(
-                                message: format!("Failed to parse date: {}", e),
+                                format!("Failed to parse date: {}", e),
-                                source_ranges: vec![SourceRange::default()],
+                                vec![SourceRange::default()],
-                            })
+                            ))
                         })?)
                     } else {
                         None
@@ -1388,10 +1383,10 @@ pub(crate) async fn parse_execute_with_project_dir(
     let exec_ctxt = ExecutorContext {
         engine: Arc::new(Box::new(
             crate::engine::conn_mock::EngineConnection::new().await.map_err(|err| {
-                KclError::Internal(crate::errors::KclErrorDetails {
+                KclError::Internal(crate::errors::KclErrorDetails::new(
-                    message: format!("Failed to create mock engine connection: {}", err),
+                    format!("Failed to create mock engine connection: {}", err),
-                    source_ranges: vec![SourceRange::default()],
+                    vec![SourceRange::default()],
-                })
+                ))
             })?,
         )),
         fs: Arc::new(crate::fs::FileManager::new()),
@@ -1804,10 +1799,10 @@ foo
         let err = result.unwrap_err();
         assert_eq!(
             err,
-            KclError::Syntax(KclErrorDetails {
+            KclError::Syntax(KclErrorDetails::new(
-                message: "Unexpected token: #".to_owned(),
+                "Unexpected token: #".to_owned(),
-                source_ranges: vec![SourceRange::new(14, 15, ModuleId::default())],
+                vec![SourceRange::new(14, 15, ModuleId::default())],
-            }),
+            )),
         );
     }
 
@@ -2063,10 +2058,10 @@ notTagIdentifier = !myTag";
             // TODO: We don't currently parse this, but we should.  It should be
             // a runtime error instead.
             parse_execute(code10).await.unwrap_err(),
-            KclError::Syntax(KclErrorDetails {
+            KclError::Syntax(KclErrorDetails::new(
-                message: "Unexpected token: !".to_owned(),
+                "Unexpected token: !".to_owned(),
-                source_ranges: vec![SourceRange::new(10, 11, ModuleId::default())],
+                vec![SourceRange::new(10, 11, ModuleId::default())],
-            })
+            ))
         );
 
         let code11 = "
@@ -2076,10 +2071,10 @@ notPipeSub = 1 |> identity(!%))";
             // TODO: We don't currently parse this, but we should.  It should be
             // a runtime error instead.
             parse_execute(code11).await.unwrap_err(),
-            KclError::Syntax(KclErrorDetails {
+            KclError::Syntax(KclErrorDetails::new(
-                message: "Unexpected token: |>".to_owned(),
+                "Unexpected token: |>".to_owned(),
-                source_ranges: vec![SourceRange::new(44, 46, ModuleId::default())],
+                vec![SourceRange::new(44, 46, ModuleId::default())],
-            })
+            ))
         );
 
         // TODO: Add these tests when we support these types.

rust/kcl-lib/src/execution/state.rs

@@ -85,14 +85,14 @@ pub(super) struct ModuleState {
     /// Settings specified from annotations.
     pub settings: MetaSettings,
     pub(super) explicit_length_units: bool,
-    pub(super) std_path: Option<String>,
+    pub(super) path: ModulePath,
 }
 
 impl ExecState {
     pub fn new(exec_context: &super::ExecutorContext) -> Self {
         ExecState {
             global: GlobalState::new(&exec_context.settings),
-            mod_local: ModuleState::new(None, ProgramMemory::new(), Default::default()),
+            mod_local: ModuleState::new(ModulePath::Main, ProgramMemory::new(), Default::default()),
             exec_context: Some(exec_context.clone()),
         }
     }
@@ -102,7 +102,7 @@ impl ExecState {
 
         *self = ExecState {
             global,
-            mod_local: ModuleState::new(None, ProgramMemory::new(), Default::default()),
+            mod_local: ModuleState::new(self.mod_local.path.clone(), ProgramMemory::new(), Default::default()),
             exec_context: Some(exec_context.clone()),
         };
     }
@@ -276,8 +276,8 @@ impl ExecState {
     }
 
     pub(super) fn circular_import_error(&self, path: &ModulePath, source_range: SourceRange) -> KclError {
-        KclError::ImportCycle(KclErrorDetails {
+        KclError::ImportCycle(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "circular import of modules is not allowed: {} -> {}",
                 self.global
                     .mod_loader
@@ -288,8 +288,8 @@ impl ExecState {
                     .join(" -> "),
                 path,
             ),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        })
+        ))
     }
 
     pub(crate) fn pipe_value(&self) -> Option<&KclValue> {
@@ -337,14 +337,14 @@ impl GlobalState {
 }
 
 impl ModuleState {
-    pub(super) fn new(std_path: Option<String>, memory: Arc<ProgramMemory>, module_id: Option<ModuleId>) -> Self {
+    pub(super) fn new(path: ModulePath, memory: Arc<ProgramMemory>, module_id: Option<ModuleId>) -> Self {
         ModuleState {
             id_generator: IdGenerator::new(module_id),
             stack: memory.new_stack(),
             pipe_value: Default::default(),
             module_exports: Default::default(),
             explicit_length_units: false,
-            std_path,
+            path,
             settings: MetaSettings {
                 default_length_units: Default::default(),
                 default_angle_units: Default::default(),
@@ -389,14 +389,14 @@ impl MetaSettings {
                     self.kcl_version = value;
                 }
                 name => {
-                    return Err(KclError::Semantic(KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
-                        message: format!(
+                        format!(
                             "Unexpected settings key: `{name}`; expected one of `{}`, `{}`",
                             annotations::SETTINGS_UNIT_LENGTH,
                             annotations::SETTINGS_UNIT_ANGLE
                         ),
-                        source_ranges: vec![annotation.as_source_range()],
+                        vec![annotation.as_source_range()],
-                    }))
+                    )))
                 }
             }
         }

rust/kcl-lib/src/execution/typed_path.rs

@@ -35,31 +35,28 @@ impl Default for TypedPath {
 
 impl From<&String> for TypedPath {
     fn from(path: &String) -> Self {
-        #[cfg(target_arch = "wasm32")]
+        TypedPath::new(path)
-        {
-            TypedPath(typed_path::TypedPath::derive(path).to_path_buf())
-        }
-        #[cfg(not(target_arch = "wasm32"))]
-        {
-            TypedPath(std::path::PathBuf::from(path))
-        }
     }
 }
 
 impl From<&str> for TypedPath {
     fn from(path: &str) -> Self {
+        TypedPath::new(path)
+    }
+}
+
+impl TypedPath {
+    pub fn new(path: &str) -> Self {
         #[cfg(target_arch = "wasm32")]
         {
             TypedPath(typed_path::TypedPath::derive(path).to_path_buf())
         }
         #[cfg(not(target_arch = "wasm32"))]
         {
-            TypedPath(std::path::PathBuf::from(path))
+            TypedPath(normalise_import(path))
         }
     }
-}
 
-impl TypedPath {
     pub fn extension(&self) -> Option<&str> {
         #[cfg(target_arch = "wasm32")]
         {
@@ -85,6 +82,17 @@ impl TypedPath {
         }
     }
 
+    pub fn join_typed(&self, path: &TypedPath) -> Self {
+        #[cfg(target_arch = "wasm32")]
+        {
+            TypedPath(self.0.join(path.0.to_path()))
+        }
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            TypedPath(self.0.join(&path.0))
+        }
+    }
+
     pub fn parent(&self) -> Option<Self> {
         #[cfg(target_arch = "wasm32")]
         {
@@ -206,3 +214,19 @@ impl schemars::JsonSchema for TypedPath {
         gen.subschema_for::<std::path::PathBuf>()
     }
 }
+
+/// Turn `nested\foo\bar\main.kcl` or `nested/foo/bar/main.kcl`
+/// into a PathBuf that works on the host OS.
+///
+/// * Does **not** touch `..` or symlinks – call `canonicalize()` if you need that.
+/// * Returns an owned `PathBuf` only when normalisation was required.
+fn normalise_import<S: AsRef<str>>(raw: S) -> std::path::PathBuf {
+    let s = raw.as_ref();
+    // On Unix we need to swap `\` → `/`.  On Windows we leave it alone.
+    // (Windows happily consumes `/`)
+    if cfg!(unix) && s.contains('\\') {
+        std::path::PathBuf::from(s.replace('\\', "/"))
+    } else {
+        std::path::Path::new(s).to_path_buf()
+    }
+}

rust/kcl-lib/src/execution/types.rs

@@ -155,9 +155,8 @@ impl RuntimeType {
                 .map(RuntimeType::Union),
             Type::Object { properties } => properties
                 .into_iter()
-                .map(|p| {
+                .map(|(id, ty)| {
-                    RuntimeType::from_parsed(p.type_.unwrap().inner, exec_state, source_range)
+                    RuntimeType::from_parsed(ty.inner, exec_state, source_range).map(|ty| (id.name.clone(), ty))
-                        .map(|ty| (p.identifier.inner.name, ty))
                 })
                 .collect::<Result<Vec<_>, CompilationError>>()
                 .map(RuntimeType::Object),

rust/kcl-lib/src/fs/local.rs

@@ -28,19 +28,19 @@ impl Default for FileManager {
 impl FileSystem for FileManager {
     async fn read(&self, path: &TypedPath, source_range: SourceRange) -> Result<Vec<u8>, KclError> {
         tokio::fs::read(&path.0).await.map_err(|e| {
-            KclError::Io(KclErrorDetails {
+            KclError::Io(KclErrorDetails::new(
-                message: format!("Failed to read file `{}`: {}", path.display(), e),
+                format!("Failed to read file `{}`: {}", path.display(), e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })
     }
 
     async fn read_to_string(&self, path: &TypedPath, source_range: SourceRange) -> Result<String, KclError> {
         tokio::fs::read_to_string(&path.0).await.map_err(|e| {
-            KclError::Io(KclErrorDetails {
+            KclError::Io(KclErrorDetails::new(
-                message: format!("Failed to read file `{}`: {}", path.display(), e),
+                format!("Failed to read file `{}`: {}", path.display(), e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })
     }
 
@@ -49,10 +49,10 @@ impl FileSystem for FileManager {
             if e.kind() == std::io::ErrorKind::NotFound {
                 Ok(false)
             } else {
-                Err(KclError::Io(KclErrorDetails {
+                Err(KclError::Io(KclErrorDetails::new(
-                    message: format!("Failed to check if file `{}` exists: {}", path.display(), e),
+                    format!("Failed to check if file `{}` exists: {}", path.display(), e),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                }))
+                )))
             }
         })
     }
@@ -71,10 +71,10 @@ impl FileSystem for FileManager {
             }
 
             let mut read_dir = tokio::fs::read_dir(&path).await.map_err(|e| {
-                KclError::Io(KclErrorDetails {
+                KclError::Io(KclErrorDetails::new(
-                    message: format!("Failed to read directory `{}`: {}", path.display(), e),
+                    format!("Failed to read directory `{}`: {}", path.display(), e),
-                    source_ranges: vec![source_range],
+                    vec![source_range],
-                })
+                ))
             })?;
 
             while let Ok(Some(entry)) = read_dir.next_entry().await {

rust/kcl-lib/src/fs/wasm.rs

@@ -46,18 +46,16 @@ unsafe impl Sync for FileManager {}
 #[async_trait::async_trait]
 impl FileSystem for FileManager {
     async fn read(&self, path: &TypedPath, source_range: SourceRange) -> Result<Vec<u8>, KclError> {
-        let promise = self.manager.read_file(path.to_string_lossy()).map_err(|e| {
+        let promise = self
-            KclError::Engine(KclErrorDetails {
+            .manager
-                message: e.to_string().into(),
+            .read_file(path.to_string_lossy())
-                source_ranges: vec![source_range],
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-            })
-        })?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to wait for promise from engine: {:?}", e),
+                format!("Failed to wait for promise from engine: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         let array = js_sys::Uint8Array::new(&value);
@@ -69,35 +67,33 @@ impl FileSystem for FileManager {
     async fn read_to_string(&self, path: &TypedPath, source_range: SourceRange) -> Result<String, KclError> {
         let bytes = self.read(path, source_range).await?;
         let string = String::from_utf8(bytes).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to convert bytes to string: {:?}", e),
+                format!("Failed to convert bytes to string: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         Ok(string)
     }
 
     async fn exists(&self, path: &TypedPath, source_range: SourceRange) -> Result<bool, crate::errors::KclError> {
-        let promise = self.manager.exists(path.to_string_lossy()).map_err(|e| {
+        let promise = self
-            KclError::Engine(KclErrorDetails {
+            .manager
-                message: e.to_string().into(),
+            .exists(path.to_string_lossy())
-                source_ranges: vec![source_range],
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-            })
-        })?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to wait for promise from engine: {:?}", e),
+                format!("Failed to wait for promise from engine: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         let it_exists = value.as_bool().ok_or_else(|| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: "Failed to convert value to bool".to_string(),
+                "Failed to convert value to bool".to_string(),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         Ok(it_exists)
@@ -108,32 +104,30 @@ impl FileSystem for FileManager {
         path: &TypedPath,
         source_range: SourceRange,
     ) -> Result<Vec<TypedPath>, crate::errors::KclError> {
-        let promise = self.manager.get_all_files(path.to_string_lossy()).map_err(|e| {
+        let promise = self
-            KclError::Engine(KclErrorDetails {
+            .manager
-                message: e.to_string().into(),
+            .get_all_files(path.to_string_lossy())
-                source_ranges: vec![source_range],
+            .map_err(|e| KclError::Engine(KclErrorDetails::new(e.to_string().into(), vec![source_range])))?;
-            })
-        })?;
 
         let value = JsFuture::from(promise).await.map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to wait for promise from javascript: {:?}", e),
+                format!("Failed to wait for promise from javascript: {:?}", e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         let s = value.as_string().ok_or_else(|| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to get string from response from javascript: `{:?}`", value),
+                format!("Failed to get string from response from javascript: `{:?}`", value),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         let files: Vec<String> = serde_json::from_str(&s).map_err(|e| {
-            KclError::Engine(KclErrorDetails {
+            KclError::Engine(KclErrorDetails::new(
-                message: format!("Failed to parse json from javascript: `{}` `{:?}`", s, e),
+                format!("Failed to parse json from javascript: `{}` `{:?}`", s, e),
-                source_ranges: vec![source_range],
+                vec![source_range],
-            })
+            ))
         })?;
 
         Ok(files.into_iter().map(|s| TypedPath::from(&s)).collect())

rust/kcl-lib/src/lib.rs

@@ -86,7 +86,8 @@ mod wasm;
 pub use coredump::CoreDump;
 pub use engine::{AsyncTasks, EngineManager, EngineStats};
 pub use errors::{
-    CompilationError, ConnectionError, ExecError, KclError, KclErrorWithOutputs, Report, ReportWithOutputs,
+    BacktraceItem, CompilationError, ConnectionError, ExecError, KclError, KclErrorWithOutputs, Report,
+    ReportWithOutputs,
 };
 pub use execution::{
     bust_cache, clear_mem_cache,

rust/kcl-lib/src/modules.rs

@@ -58,8 +58,8 @@ impl ModuleLoader {
     }
 
     pub(crate) fn import_cycle_error(&self, path: &ModulePath, source_range: SourceRange) -> KclError {
-        KclError::ImportCycle(KclErrorDetails {
+        KclError::ImportCycle(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "circular import of modules is not allowed: {} -> {}",
                 self.import_stack
                     .iter()
@@ -68,8 +68,8 @@ impl ModuleLoader {
                     .join(" -> "),
                 path,
             ),
-            source_ranges: vec![source_range],
+            vec![source_range],
-        })
+        ))
     }
 
     pub(crate) fn enter_module(&mut self, path: &ModulePath) {
@@ -153,13 +153,6 @@ impl ModulePath {
         }
     }
 
-    pub(crate) fn std_path(&self) -> Option<String> {
-        match self {
-            ModulePath::Std { value: p } => Some(p.clone()),
-            _ => None,
-        }
-    }
-
     pub(crate) async fn source(&self, fs: &FileManager, source_range: SourceRange) -> Result<ModuleSource, KclError> {
         match self {
             ModulePath::Local { value: p } => Ok(ModuleSource {
@@ -169,10 +162,10 @@ impl ModulePath {
             ModulePath::Std { value: name } => Ok(ModuleSource {
                 source: read_std(name)
                     .ok_or_else(|| {
-                        KclError::Semantic(KclErrorDetails {
+                        KclError::Semantic(KclErrorDetails::new(
-                            message: format!("Cannot find standard library module to import: std::{name}."),
+                            format!("Cannot find standard library module to import: std::{name}."),
-                            source_ranges: vec![source_range],
+                            vec![source_range],
-                        })
+                        ))
                     })
                     .map(str::to_owned)?,
                 path: self.clone(),
@@ -181,25 +174,53 @@ impl ModulePath {
         }
     }
 
-    pub(crate) fn from_import_path(path: &ImportPath, project_directory: &Option<TypedPath>) -> Self {
+    pub(crate) fn from_import_path(
+        path: &ImportPath,
+        project_directory: &Option<TypedPath>,
+        import_from: &ModulePath,
+    ) -> Result<Self, KclError> {
         match path {
             ImportPath::Kcl { filename: path } | ImportPath::Foreign { path } => {
-                let resolved_path = if let Some(project_dir) = project_directory {
+                let resolved_path = match import_from {
-                    project_dir.join(path)
+                    ModulePath::Main => {
-                } else {
+                        if let Some(project_dir) = project_directory {
-                    TypedPath::from(path)
+                            project_dir.join_typed(path)
+                        } else {
+                            path.clone()
+                        }
+                    }
+                    ModulePath::Local { value } => {
+                        let import_from_dir = value.parent();
+                        let base = import_from_dir.as_ref().or(project_directory.as_ref());
+                        if let Some(dir) = base {
+                            dir.join_typed(path)
+                        } else {
+                            path.clone()
+                        }
+                    }
+                    ModulePath::Std { .. } => {
+                        let message = format!("Cannot import a non-std KCL file from std: {path}.");
+                        debug_assert!(false, "{}", &message);
+                        return Err(KclError::Internal(KclErrorDetails::new(message, vec![])));
+                    }
                 };
-                ModulePath::Local { value: resolved_path }
-            }
-            ImportPath::Std { path } => {
-                // For now we only support importing from singly-nested modules inside std.
-                assert_eq!(path.len(), 2);
-                assert_eq!(&path[0], "std");
 
-                ModulePath::Std { value: path[1].clone() }
+                Ok(ModulePath::Local { value: resolved_path })
             }
+            ImportPath::Std { path } => Self::from_std_import_path(path),
         }
     }
+
+    pub(crate) fn from_std_import_path(path: &[String]) -> Result<Self, KclError> {
+        // For now we only support importing from singly-nested modules inside std.
+        if path.len() != 2 || path[0] != "std" {
+            let message = format!("Invalid std import path: {path:?}.");
+            debug_assert!(false, "{}", &message);
+            return Err(KclError::Internal(KclErrorDetails::new(message, vec![])));
+        }
+
+        Ok(ModulePath::Std { value: path[1].clone() })
+    }
 }
 
 impl fmt::Display for ModulePath {

rust/kcl-lib/src/parsing/ast/digest.rs

@@ -212,8 +212,9 @@ impl Type {
             Type::Object { properties } => {
                 hasher.update(b"FnArgType::Object");
                 hasher.update(properties.len().to_ne_bytes());
-                for prop in properties.iter_mut() {
+                for (id, ty) in properties.iter_mut() {
-                    hasher.update(prop.compute_digest());
+                    hasher.update(id.compute_digest());
+                    hasher.update(ty.compute_digest());
                 }
             }
         }

rust/kcl-lib/src/parsing/ast/types/mod.rs

@@ -34,7 +34,7 @@ use crate::{
     },
     parsing::{ast::digest::Digest, token::NumericSuffix, PIPE_OPERATOR},
     source_range::SourceRange,
-    ModuleId,
+    ModuleId, TypedPath,
 };
 
 mod condition;
@@ -1741,8 +1741,8 @@ impl ImportSelector {
 #[ts(export)]
 #[serde(tag = "type")]
 pub enum ImportPath {
-    Kcl { filename: String },
+    Kcl { filename: TypedPath },
-    Foreign { path: String },
+    Foreign { path: TypedPath },
     Std { path: Vec<String> },
 }
 
@@ -1811,16 +1811,25 @@ impl ImportStatement {
 
         match &self.path {
             ImportPath::Kcl { filename: s } | ImportPath::Foreign { path: s } => {
-                let mut parts = s.split('.');
+                let name = s.to_string_lossy();
-                let path = parts.next()?;
+                if name.ends_with("/main.kcl") || name.ends_with("\\main.kcl") {
-                let _ext = parts.next()?;
+                    let name = &name[..name.len() - 9];
-                let rest = parts.next();
+                    let start = name.rfind(['/', '\\']).map(|s| s + 1).unwrap_or(0);
+                    return Some(name[start..].to_owned());
+                }
 
-                if rest.is_some() {
+                let name = s.file_name().map(|f| f.to_string())?;
+                if name.contains('\\') || name.contains('/') {
                     return None;
                 }
 
-                path.rsplit(&['/', '\\']).next().map(str::to_owned)
+                // Remove the extension if it exists.
+                let extension = s.extension();
+                Some(if let Some(extension) = extension {
+                    name.trim_end_matches(extension).trim_end_matches('.').to_string()
+                } else {
+                    name
+                })
             }
             ImportPath::Std { path } => path.last().cloned(),
         }
@@ -3315,7 +3324,7 @@ pub enum Type {
     },
     // An object type.
     Object {
-        properties: Vec<Parameter>,
+        properties: Vec<(Node<Identifier>, Node<Type>)>,
     },
 }
 
@@ -3348,10 +3357,8 @@ impl fmt::Display for Type {
                     } else {
                         write!(f, ",")?;
                     }
-                    write!(f, " {}:", p.identifier.name)?;
+                    write!(f, " {}:", p.0.name)?;
-                    if let Some(ty) = &p.type_ {
+                    write!(f, " {}", p.1)?;
-                        write!(f, " {}", ty.inner)?;
-                    }
                 }
                 write!(f, " }}")
             }
@@ -3988,7 +3995,7 @@ cylinder = startSketchOn(-XZ)
 
     #[tokio::test(flavor = "multi_thread")]
     async fn test_parse_type_args_object_on_functions() {
-        let some_program_string = r#"fn thing(arg0: [number], arg1: {thing: number, things: [string], more?: string}, tag?: string) {
+        let some_program_string = r#"fn thing(arg0: [number], arg1: {thing: number, things: [string], more: string}, tag?: string) {
     return arg0
 }"#;
         let module_id = ModuleId::default();
@@ -4015,8 +4022,8 @@ cylinder = startSketchOn(-XZ)
             params[1].type_.as_ref().unwrap().inner,
             Type::Object {
                 properties: vec![
-                    Parameter {
+                    (
-                        identifier: Node::new(
+                        Node::new(
                             Identifier {
                                 name: "thing".to_owned(),
                                 digest: None,
@@ -4025,18 +4032,15 @@ cylinder = startSketchOn(-XZ)
                             37,
                             module_id,
                         ),
-                        type_: Some(Node::new(
+                        Node::new(
                             Type::Primitive(PrimitiveType::Number(NumericSuffix::None)),
                             39,
                             45,
                             module_id
-                        )),
+                        ),
-                        default_value: None,
+                    ),
-                        labeled: true,
+                    (
-                        digest: None,
+                        Node::new(
-                    },
-                    Parameter {
-                        identifier: Node::new(
                             Identifier {
                                 name: "things".to_owned(),
                                 digest: None,
@@ -4045,7 +4049,7 @@ cylinder = startSketchOn(-XZ)
                             53,
                             module_id,
                         ),
-                        type_: Some(Node::new(
+                        Node::new(
                             Type::Array {
                                 ty: Box::new(Type::Primitive(PrimitiveType::String)),
                                 len: ArrayLen::None
@@ -4053,13 +4057,10 @@ cylinder = startSketchOn(-XZ)
                             56,
                             62,
                             module_id
-                        )),
+                        )
-                        default_value: None,
+                    ),
-                        labeled: true,
+                    (
-                        digest: None
+                        Node::new(
-                    },
-                    Parameter {
-                        identifier: Node::new(
                             Identifier {
                                 name: "more".to_owned(),
                                 digest: None
@@ -4068,11 +4069,8 @@ cylinder = startSketchOn(-XZ)
                             69,
                             module_id,
                         ),
-                        type_: Some(Node::new(Type::Primitive(PrimitiveType::String), 72, 78, module_id)),
+                        Node::new(Type::Primitive(PrimitiveType::String), 71, 77, module_id),
-                        labeled: true,
+                    )
-                        default_value: Some(DefaultParamVal::none()),
-                        digest: None
-                    }
                 ]
             }
         );
@@ -4343,4 +4341,20 @@ startSketchOn(XY)
 "#
         );
     }
+
+    #[test]
+    fn module_name() {
+        #[track_caller]
+        fn assert_mod_name(stmt: &str, name: &str) {
+            let tokens = crate::parsing::token::lex(stmt, ModuleId::default()).unwrap();
+            let stmt = crate::parsing::parser::import_stmt(&mut tokens.as_slice()).unwrap();
+            assert_eq!(stmt.module_name().unwrap(), name);
+        }
+
+        assert_mod_name("import 'foo.kcl'", "foo");
+        assert_mod_name("import 'foo.kcl' as bar", "bar");
+        assert_mod_name("import 'main.kcl'", "main");
+        assert_mod_name("import 'foo/main.kcl'", "foo");
+        assert_mod_name("import 'foo\\bar\\main.kcl'", "bar");
+    }
 }

rust/kcl-lib/src/parsing/mod.rs

@@ -51,7 +51,7 @@ pub fn parse_tokens(mut tokens: TokenStream) -> ParseResult {
         } else {
             format!("found unknown tokens [{}]", token_list.join(", "))
         };
-        return KclError::Lexical(KclErrorDetails { source_ranges, message }).into();
+        return KclError::Lexical(KclErrorDetails::new(message, source_ranges)).into();
     }
 
     // Important, to not call this before the unknown tokens check.

rust/kcl-lib/src/parsing/parser.rs

@@ -35,7 +35,7 @@ use crate::{
         token::{Token, TokenSlice, TokenType},
         PIPE_OPERATOR, PIPE_SUBSTITUTION_OPERATOR,
     },
-    SourceRange, IMPORT_FILE_EXTENSIONS,
+    SourceRange, TypedPath, IMPORT_FILE_EXTENSIONS,
 };
 
 thread_local! {
@@ -436,7 +436,7 @@ fn pipe_expression(i: &mut TokenSlice) -> PResult<Node<PipeExpression>> {
     ))
 }
 
-fn bool_value(i: &mut TokenSlice) -> PResult<BoxNode<Literal>> {
+fn bool_value(i: &mut TokenSlice) -> PResult<Node<Literal>> {
     let (value, token) = any
         .try_map(|token: Token| match token.token_type {
             TokenType::Keyword if token.value == "true" => Ok((true, token)),
@@ -448,7 +448,7 @@ fn bool_value(i: &mut TokenSlice) -> PResult<BoxNode<Literal>> {
         })
         .context(expected("a boolean literal (either true or false)"))
         .parse_next(i)?;
-    Ok(Box::new(Node::new(
+    Ok(Node::new(
         Literal {
             value: LiteralValue::Bool(value),
             raw: value.to_string(),
@@ -457,11 +457,11 @@ fn bool_value(i: &mut TokenSlice) -> PResult<BoxNode<Literal>> {
         token.start,
         token.end,
         token.module_id,
-    )))
+    ))
 }
 
 fn literal(i: &mut TokenSlice) -> PResult<BoxNode<Literal>> {
-    alt((string_literal, unsigned_number_literal))
+    alt((string_literal, unsigned_number_literal, bool_value))
         .map(Box::new)
         .context(expected("a KCL literal, like 'myPart' or 3"))
         .parse_next(i)
@@ -1729,7 +1729,7 @@ fn glob(i: &mut TokenSlice) -> PResult<Token> {
         .parse_next(i)
 }
 
-fn import_stmt(i: &mut TokenSlice) -> PResult<BoxNode<ImportStatement>> {
+pub(super) fn import_stmt(i: &mut TokenSlice) -> PResult<BoxNode<ImportStatement>> {
     let (visibility, visibility_token) = opt(terminated(item_visibility, whitespace))
         .parse_next(i)?
         .map_or((ItemVisibility::Default, None), |pair| (pair.0, Some(pair.1)));
@@ -1862,18 +1862,50 @@ fn validate_path_string(path_string: String, var_name: bool, path_range: SourceR
     let path = if path_string.ends_with(".kcl") {
         if path_string
             .chars()
-            .any(|c| !c.is_ascii_alphanumeric() && c != '_' && c != '-' && c != '.')
+            .any(|c| !c.is_ascii_alphanumeric() && c != '_' && c != '-' && c != '.' && c != '/' && c != '\\')
         {
             return Err(ErrMode::Cut(
                 CompilationError::fatal(
                     path_range,
-                    "import path may only contain alphanumeric characters, underscore, hyphen, and period. KCL files in other directories are not yet supported.",
+                    "import path may only contain alphanumeric characters, `_`, `-`, `.`, `/`, and `\\`.",
                 )
                 .into(),
             ));
         }
 
-        ImportPath::Kcl { filename: path_string }
+        if path_string.starts_with("..") {
+            return Err(ErrMode::Cut(
+                CompilationError::fatal(
+                    path_range,
+                    "import path may not start with '..'. Cannot traverse to something outside the bounds of your project. If this path is inside your project please find a better way to reference it.",
+                )
+                .into(),
+            ));
+        }
+
+        // Make sure they are not using an absolute path.
+        if path_string.starts_with('/') || path_string.starts_with('\\') {
+            return Err(ErrMode::Cut(
+                CompilationError::fatal(
+                    path_range,
+                    "import path may not start with '/' or '\\'. Cannot traverse to something outside the bounds of your project. If this path is inside your project please find a better way to reference it.",
+                )
+                .into(),
+            ));
+        }
+
+        if (path_string.contains('/') || path_string.contains('\\'))
+            && !(path_string.ends_with("/main.kcl") || path_string.ends_with("\\main.kcl"))
+        {
+            return Err(ErrMode::Cut(
+                CompilationError::fatal(path_range, "import path to a subdirectory must only refer to main.kcl.")
+                    .into(),
+            ));
+        }
+
+        ImportPath::Kcl {
+            filename: TypedPath::new(&path_string),
+        }
     } else if path_string.starts_with("std::") {
         ParseContext::warn(CompilationError::err(
             path_range,
@@ -1910,7 +1942,9 @@ fn validate_path_string(path_string: String, var_name: bool, path_range: SourceR
                 format!("unsupported import path format. KCL files can be imported from the current project, CAD files with the following formats are supported: {}", IMPORT_FILE_EXTENSIONS.join(", ")),
             ))
         }
-        ImportPath::Foreign { path: path_string }
+        ImportPath::Foreign {
+            path: TypedPath::new(&path_string),
+        }
     } else {
         return Err(ErrMode::Cut(
             CompilationError::fatal(
@@ -2051,7 +2085,7 @@ fn unnecessarily_bracketed(i: &mut TokenSlice) -> PResult<Expr> {
 fn expr_allowed_in_pipe_expr(i: &mut TokenSlice) -> PResult<Expr> {
     alt((
         member_expression.map(Box::new).map(Expr::MemberExpression),
-        bool_value.map(Expr::Literal),
+        bool_value.map(Box::new).map(Expr::Literal),
         tag.map(Box::new).map(Expr::TagDeclarator),
         literal.map(Expr::Literal),
         fn_call_kw.map(Box::new).map(Expr::CallExpressionKw),
@@ -2070,7 +2104,7 @@ fn expr_allowed_in_pipe_expr(i: &mut TokenSlice) -> PResult<Expr> {
 fn possible_operands(i: &mut TokenSlice) -> PResult<Expr> {
     let mut expr = alt((
         unary_expression.map(Box::new).map(Expr::UnaryExpression),
-        bool_value.map(Expr::Literal),
+        bool_value.map(Box::new).map(Expr::Literal),
         member_expression.map(Box::new).map(Expr::MemberExpression),
         literal.map(Expr::Literal),
         fn_call_kw.map(Box::new).map(Expr::CallExpressionKw),
@@ -2780,27 +2814,31 @@ fn labeled_argument(i: &mut TokenSlice) -> PResult<LabeledArg> {
         .parse_next(i)
 }
 
+fn record_ty_field(i: &mut TokenSlice) -> PResult<(Node<Identifier>, Node<Type>)> {
+    (identifier, colon, opt(whitespace), type_)
+        .map(|(id, _, _, ty)| (id, ty))
+        .parse_next(i)
+}
+
 /// Parse a type in various positions.
 fn type_(i: &mut TokenSlice) -> PResult<Node<Type>> {
     let type_ = alt((
         // Object types
-        // TODO it is buggy to treat object fields like parameters since the parameters parser assumes a terminating `)`.
+        (
-        (open_brace, parameters, close_brace).try_map(|(open, params, close)| {
+            open_brace,
-            for p in &params {
+            opt(whitespace),
-                if p.type_.is_none() {
+            separated(0.., record_ty_field, comma_sep),
-                    return Err(CompilationError::fatal(
+            opt(whitespace),
-                        p.identifier.as_source_range(),
+            close_brace,
-                        "Missing type for field in record type",
+        )
-                    ));
+            .try_map(|(open, _, params, _, close)| {
-                }
+                Ok(Node::new(
-            }
+                    Type::Object { properties: params },
-            Ok(Node::new(
+                    open.start,
-                Type::Object { properties: params },
+                    close.end,
-                open.start,
+                    open.module_id,
-                close.end,
+                ))
-                open.module_id,
+            }),
-            ))
-        }),
         // Array types
         array_type,
         // Primitive or union types
@@ -4530,9 +4568,24 @@ e
     fn bad_imports() {
         assert_err(
             r#"import cube from "../cube.kcl""#,
-            "import path may only contain alphanumeric characters, underscore, hyphen, and period. KCL files in other directories are not yet supported.",
+            "import path may not start with '..'. Cannot traverse to something outside the bounds of your project. If this path is inside your project please find a better way to reference it.",
             [17, 30],
         );
+        assert_err(
+            r#"import cube from "/cube.kcl""#,
+            "import path may not start with '/' or '\\'. Cannot traverse to something outside the bounds of your project. If this path is inside your project please find a better way to reference it.",
+            [17, 28],
+        );
+        assert_err(
+            r#"import cube from "C:\cube.kcl""#,
+            "import path may only contain alphanumeric characters, `_`, `-`, `.`, `/`, and `\\`.",
+            [17, 30],
+        );
+        assert_err(
+            r#"import cube from "cube/cube.kcl""#,
+            "import path to a subdirectory must only refer to main.kcl.",
+            [17, 32],
+        );
         assert_err(
             r#"import * as foo from "dsfs""#,
             "as is not the 'from' keyword",
@@ -4866,6 +4919,15 @@ let myBox = box(p=[0,0], h=-3, l=-16, w=-10)
     |> line(%, tag = $var01)"#;
         assert_no_err(some_program_string);
     }
+
+    #[test]
+    fn test_parse_param_bool_default() {
+        let some_program_string = r#"fn patternTransform(
+  use_original?: boolean = false,
+) {}"#;
+        assert_no_err(some_program_string);
+    }
+
     #[test]
     fn parse_function_types() {
         let code = r#"foo = x: fn
@@ -4875,6 +4937,8 @@ fn foo(x: fn(a, b: number(mm), c: d): number(Angle)): fn { return 0 }
 type fn
 type foo = fn
 type foo = fn(a: string, b: { f: fn(): any })
+type foo = fn(a: string, b: {})
+type foo = fn(a: string, b: { })
 type foo = fn([fn])
 type foo = fn(fn, f: fn(number(_))): [fn([any]): string]
     "#;

rust/kcl-lib/src/parsing/token/mod.rs

@@ -578,10 +578,10 @@ impl From<ParseError<Input<'_>, winnow::error::ContextError>> for KclError {
             // This is an offset, not an index, and may point to
             // the end of input (input.len()) on eof errors.
 
-            return KclError::Lexical(crate::errors::KclErrorDetails {
+            return KclError::Lexical(crate::errors::KclErrorDetails::new(
-                source_ranges: vec![SourceRange::new(offset, offset, module_id)],
+                "unexpected EOF while parsing".to_owned(),
-                message: "unexpected EOF while parsing".to_string(),
+                vec![SourceRange::new(offset, offset, module_id)],
-            });
+            ));
         }
 
         // TODO: Add the Winnow tokenizer context to the error.
@@ -589,9 +589,9 @@ impl From<ParseError<Input<'_>, winnow::error::ContextError>> for KclError {
         let bad_token = &input[offset];
         // TODO: Add the Winnow parser context to the error.
         // See https://github.com/KittyCAD/modeling-app/issues/784
-        KclError::Lexical(crate::errors::KclErrorDetails {
+        KclError::Lexical(crate::errors::KclErrorDetails::new(
-            source_ranges: vec![SourceRange::new(offset, offset + 1, module_id)],
+            format!("found unknown token '{}'", bad_token),
-            message: format!("found unknown token '{}'", bad_token),
+            vec![SourceRange::new(offset, offset + 1, module_id)],
-        })
+        ))
     }
 }

rust/kcl-lib/src/simulation_tests.rs

@@ -384,6 +384,27 @@ mod any_type {
         super::execute(TEST_NAME, false).await
     }
 }
+mod error_with_point_shows_numeric_units {
+    const TEST_NAME: &str = "error_with_point_shows_numeric_units";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}
 mod artifact_graph_example_code1 {
     const TEST_NAME: &str = "artifact_graph_example_code1";
 
@@ -996,6 +1017,27 @@ mod import_cycle1 {
         super::execute(TEST_NAME, false).await
     }
 }
+mod import_only_at_top_level {
+    const TEST_NAME: &str = "import_only_at_top_level";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, false).await
+    }
+}
 mod import_function_not_sketch {
     const TEST_NAME: &str = "import_function_not_sketch";
 
@@ -1164,6 +1206,27 @@ mod import_foreign {
         super::execute(TEST_NAME, false).await
     }
 }
+mod export_var_only_at_top_level {
+    const TEST_NAME: &str = "export_var_only_at_top_level";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, false).await
+    }
+}
 mod assembly_non_default_units {
     const TEST_NAME: &str = "assembly_non_default_units";
 
@@ -3188,7 +3251,6 @@ mod revolve_colinear {
 
     /// Test that KCL is executed correctly.
     #[tokio::test(flavor = "multi_thread")]
-    #[ignore] // until https://github.com/KittyCAD/engine/pull/3417 lands
     async fn kcl_test_execute() {
         super::execute(TEST_NAME, true).await
     }
@@ -3277,3 +3339,108 @@ mod subtract_regression10 {
         super::execute(TEST_NAME, true).await
     }
 }
+mod nested_main_kcl {
+    const TEST_NAME: &str = "nested_main_kcl";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}
+mod nested_windows_main_kcl {
+    const TEST_NAME: &str = "nested_windows_main_kcl";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}
+mod nested_assembly {
+    const TEST_NAME: &str = "nested_assembly";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}
+mod subtract_regression11 {
+    const TEST_NAME: &str = "subtract_regression11";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}
+mod subtract_regression12 {
+    const TEST_NAME: &str = "subtract_regression12";
+
+    /// Test parsing KCL.
+    #[test]
+    fn parse() {
+        super::parse(TEST_NAME)
+    }
+
+    /// Test that parsing and unparsing KCL produces the original KCL input.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn unparse() {
+        super::unparse(TEST_NAME).await
+    }
+
+    /// Test that KCL is executed correctly.
+    #[tokio::test(flavor = "multi_thread")]
+    async fn kcl_test_execute() {
+        super::execute(TEST_NAME, true).await
+    }
+}

rust/kcl-lib/src/std/appearance.rs

@@ -32,10 +32,10 @@ pub async fn appearance(exec_state: &mut ExecState, args: Args) -> Result<KclVal
 
     // Make sure the color if set is valid.
     if !HEX_REGEX.is_match(&color) {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: format!("Invalid hex color (`{}`), try something like `#fff000`", color),
+            format!("Invalid hex color (`{}`), try something like `#fff000`", color),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let result = inner_appearance(
@@ -282,10 +282,10 @@ async fn inner_appearance(
     for solid_id in solids.ids(&args.ctx).await? {
         // Set the material properties.
         let rgb = rgba_simple::RGB::<f32>::from_hex(&color).map_err(|err| {
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(
-                message: format!("Invalid hex color (`{color}`): {err}"),
+                format!("Invalid hex color (`{color}`): {err}"),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            })
+            ))
         })?;
 
         let color = Color {

rust/kcl-lib/src/std/args.rs

@@ -9,6 +9,7 @@ use kittycad_modeling_cmds as kcmc;
 use schemars::JsonSchema;
 use serde::Serialize;
 
+pub use crate::execution::fn_call::Args;
 use crate::{
     errors::{KclError, KclErrorDetails},
     execution::{
@@ -27,8 +28,6 @@ use crate::{
     ModuleId,
 };
 
-pub use crate::execution::fn_call::Args;
-
 const ERROR_STRING_SKETCH_TO_SOLID_HELPER: &str =
     "You can convert a sketch (2D) into a Solid (3D) by calling a function like `extrude` or `revolve`";
 
@@ -122,14 +121,14 @@ impl Args {
         }
 
         T::from_kcl_val(&arg.value).map(Some).ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
+            KclError::Type(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!(
-                message: format!(
                     "The arg {label} was given, but it was the wrong type. It should be type {} but it was {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type(),
                 ),
-            })
+                vec![self.source_range],
+            ))
         })
     }
 
@@ -155,10 +154,10 @@ impl Args {
         T: FromKclValue<'a>,
     {
         self.get_kw_arg_opt(label)?.ok_or_else(|| {
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!("This function requires a keyword argument '{label}'"),
-                message: format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
-            })
+            ))
         })
     }
 
@@ -172,10 +171,10 @@ impl Args {
         T: for<'a> FromKclValue<'a>,
     {
         let Some(arg) = self.kw_args.labeled.get(label) else {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!("This function requires a keyword argument '{label}'"),
-                message: format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
-            }));
+            )));
         };
 
         let arg = arg.value.coerce(ty, exec_state).map_err(|_| {
@@ -206,10 +205,7 @@ impl Args {
             if message.contains("one or more Solids or imported geometry but it's actually of type Sketch") {
                 message = format!("{message}. {ERROR_STRING_SKETCH_TO_SOLID_HELPER}");
             }
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(message, arg.source_ranges()))
-                source_ranges: arg.source_ranges(),
-                message,
-            })
         })?;
 
         // TODO unnecessary cloning
@@ -223,21 +219,21 @@ impl Args {
         T: FromKclValue<'a>,
     {
         let Some(arg) = self.kw_args.labeled.get(label) else {
-            let err = KclError::Semantic(KclErrorDetails {
+            let err = KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!("This function requires a keyword argument '{label}'"),
-                message: format!("This function requires a keyword argument '{label}'"),
+                vec![self.source_range],
-            });
+            ));
             return Err(err);
         };
         let Some(array) = arg.value.as_array() else {
-            let err = KclError::Semantic(KclErrorDetails {
+            let err = KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![arg.source_range],
+                format!(
-                message: format!(
                     "Expected an array of {} but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type()
                 ),
-            });
+                vec![arg.source_range],
+            ));
             return Err(err);
         };
         array
@@ -245,14 +241,14 @@ impl Args {
             .map(|item| {
                 let source = SourceRange::from(item);
                 let val = FromKclValue::from_kcl_val(item).ok_or_else(|| {
-                    KclError::Semantic(KclErrorDetails {
+                    KclError::Semantic(KclErrorDetails::new(
-                        source_ranges: arg.source_ranges(),
+                        format!(
-                        message: format!(
                             "Expected a {} but found {}",
                             tynm::type_name::<T>(),
                             arg.value.human_friendly_type()
                         ),
-                    })
+                        arg.source_ranges(),
+                    ))
                 })?;
                 Ok((val, source))
             })
@@ -267,19 +263,19 @@ impl Args {
     {
         let arg = self
             .unlabeled_kw_arg_unconverted()
-            .ok_or(KclError::Semantic(KclErrorDetails {
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
-                message: format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
+                vec![self.source_range],
-            }))?;
+            )))?;
 
         T::from_kcl_val(&arg.value).ok_or_else(|| {
             let expected_type_name = tynm::type_name::<T>();
             let actual_type_name = arg.value.human_friendly_type();
             let message = format!("This function expected the input argument to be of type {expected_type_name} but it's actually of type {actual_type_name}");
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(
-                source_ranges: arg.source_ranges(),
                 message,
-            })
+                arg.source_ranges(),
+            ))
         })
     }
 
@@ -296,10 +292,10 @@ impl Args {
     {
         let arg = self
             .unlabeled_kw_arg_unconverted()
-            .ok_or(KclError::Semantic(KclErrorDetails {
+            .ok_or(KclError::Semantic(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
-                message: format!("This function requires a value for the special unlabeled first parameter, '{label}'"),
+                vec![self.source_range],
-            }))?;
+            )))?;
 
         let arg = arg.value.coerce(ty, exec_state).map_err(|_| {
             let actual_type = arg.value.principal_type();
@@ -330,17 +326,14 @@ impl Args {
             if message.contains("one or more Solids or imported geometry but it's actually of type Sketch") {
                 message = format!("{message}. {ERROR_STRING_SKETCH_TO_SOLID_HELPER}");
             }
-            KclError::Semantic(KclErrorDetails {
+            KclError::Semantic(KclErrorDetails::new(message, arg.source_ranges()))
-                source_ranges: arg.source_ranges(),
-                message,
-            })
         })?;
 
         T::from_kcl_val(&arg).ok_or_else(|| {
-            KclError::Internal(KclErrorDetails {
+            KclError::Internal(KclErrorDetails::new(
-                source_ranges: vec![self.source_range],
+                "Mismatch between type coercion and value extraction (this isn't your fault).\nTo assist in bug-reporting, expected type: {ty:?}; actual value: {arg:?}".to_owned(),
-                message: "Mismatch between type coercion and value extraction (this isn't your fault).\nTo assist in bug-reporting, expected type: {ty:?}; actual value: {arg:?}".to_owned(),
+                vec![self.source_range],
-           })
+           ))
         })
     }
 
@@ -383,17 +376,17 @@ impl Args {
             exec_state.stack().get_from_call_stack(&tag.value, self.source_range)?
         {
             let info = t.get_info(epoch).ok_or_else(|| {
-                KclError::Type(KclErrorDetails {
+                KclError::Type(KclErrorDetails::new(
-                    message: format!("Tag `{}` does not have engine info", tag.value),
+                    format!("Tag `{}` does not have engine info", tag.value),
-                    source_ranges: vec![self.source_range],
+                    vec![self.source_range],
-                })
+                ))
             })?;
             Ok(info)
         } else {
-            Err(KclError::Type(KclErrorDetails {
+            Err(KclError::Type(KclErrorDetails::new(
-                message: format!("Tag `{}` does not exist", tag.value),
+                format!("Tag `{}` does not exist", tag.value),
-                source_ranges: vec![self.source_range],
+                vec![self.source_range],
-            }))
+            )))
         }
     }
 
@@ -522,19 +515,19 @@ impl Args {
         must_be_planar: bool,
     ) -> Result<uuid::Uuid, KclError> {
         if tag.value.is_empty() {
-            return Err(KclError::Type(KclErrorDetails {
+            return Err(KclError::Type(KclErrorDetails::new(
-                message: "Expected a non-empty tag for the face".to_string(),
+                "Expected a non-empty tag for the face".to_string(),
-                source_ranges: vec![self.source_range],
+                vec![self.source_range],
-            }));
+            )));
         }
 
         let engine_info = self.get_tag_engine_info_check_surface(exec_state, tag)?;
 
         let surface = engine_info.surface.as_ref().ok_or_else(|| {
-            KclError::Type(KclErrorDetails {
+            KclError::Type(KclErrorDetails::new(
-                message: format!("Tag `{}` does not have a surface", tag.value),
+                format!("Tag `{}` does not have a surface", tag.value),
-                source_ranges: vec![self.source_range],
+                vec![self.source_range],
-            })
+            ))
         })?;
 
         if let Some(face_from_surface) = match surface {
@@ -550,10 +543,10 @@ impl Args {
                 }
             }
             // The must be planar check must be called before the arc check.
-            ExtrudeSurface::ExtrudeArc(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails {
+            ExtrudeSurface::ExtrudeArc(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails::new(
-                message: format!("Tag `{}` is a non-planar surface", tag.value),
+                format!("Tag `{}` is a non-planar surface", tag.value),
-                source_ranges: vec![self.source_range],
+                vec![self.source_range],
-            }))),
+            )))),
             ExtrudeSurface::ExtrudeArc(extrude_arc) => {
                 if let Some(arc_tag) = &extrude_arc.tag {
                     if arc_tag.name == tag.value {
@@ -577,10 +570,10 @@ impl Args {
                 }
             }
             // The must be planar check must be called before the fillet check.
-            ExtrudeSurface::Fillet(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails {
+            ExtrudeSurface::Fillet(_) if must_be_planar => Some(Err(KclError::Type(KclErrorDetails::new(
-                message: format!("Tag `{}` is a non-planar surface", tag.value),
+                format!("Tag `{}` is a non-planar surface", tag.value),
-                source_ranges: vec![self.source_range],
+                vec![self.source_range],
-            }))),
+            )))),
             ExtrudeSurface::Fillet(fillet) => {
                 if let Some(fillet_tag) = &fillet.tag {
                     if fillet_tag.name == tag.value {
@@ -597,10 +590,10 @@ impl Args {
         }
 
         // If we still haven't found the face, return an error.
-        Err(KclError::Type(KclErrorDetails {
+        Err(KclError::Type(KclErrorDetails::new(
-            message: format!("Expected a face with the tag `{}`", tag.value),
+            format!("Expected a face with the tag `{}`", tag.value),
-            source_ranges: vec![self.source_range],
+            vec![self.source_range],
-        }))
+        )))
     }
 }
 
@@ -622,20 +615,20 @@ where
 {
     fn from_args(args: &'a Args, i: usize) -> Result<Self, KclError> {
         let Some(arg) = args.args.get(i) else {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!("Expected an argument at index {i}"),
+                format!("Expected an argument at index {i}"),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            }));
+            )));
         };
         let Some(val) = T::from_kcl_val(&arg.value) else {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "Argument at index {i} was supposed to be type {} but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type(),
                 ),
-                source_ranges: arg.source_ranges(),
+                arg.source_ranges(),
-            }));
+            )));
         };
         Ok(val)
     }
@@ -651,14 +644,14 @@ where
             return Ok(None);
         }
         let Some(val) = T::from_kcl_val(&arg.value) else {
-            return Err(KclError::Semantic(KclErrorDetails {
+            return Err(KclError::Semantic(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "Argument at index {i} was supposed to be type Option<{}> but found {}",
                     tynm::type_name::<T>(),
                     arg.value.human_friendly_type()
                 ),
-                source_ranges: arg.source_ranges(),
+                arg.source_ranges(),
-            }));
+            )));
         };
         Ok(Some(val))
     }

rust/kcl-lib/src/std/array.rs

@@ -58,10 +58,10 @@ async fn call_map_closure(
     let output = map_fn.call_kw(None, exec_state, ctxt, args, source_range).await?;
     let source_ranges = vec![source_range];
     let output = output.ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: "Map function must return a value".to_string(),
+            "Map function must return a value".to_owned(),
             source_ranges,
-        })
+        ))
     })?;
     Ok(output)
 }
@@ -118,10 +118,10 @@ async fn call_reduce_closure(
     // Unpack the returned transform object.
     let source_ranges = vec![source_range];
     let out = transform_fn_return.ok_or_else(|| {
-        KclError::Semantic(KclErrorDetails {
+        KclError::Semantic(KclErrorDetails::new(
-            message: "Reducer function must return a value".to_string(),
+            "Reducer function must return a value".to_string(),
-            source_ranges: source_ranges.clone(),
+            source_ranges.clone(),
-        })
+        ))
     })?;
     Ok(out)
 }
@@ -133,10 +133,10 @@ pub async fn push(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
     let KclValue::HomArray { value: values, ty } = array else {
         let meta = vec![args.source_range];
         let actual_type = array.human_friendly_type();
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            source_ranges: meta,
+            format!("You can't push to a value of type {actual_type}, only an array"),
-            message: format!("You can't push to a value of type {actual_type}, only an array"),
+            meta,
-        }));
+        )));
     };
     let ty = if item.has_type(&ty) {
         ty
@@ -161,10 +161,10 @@ pub async fn pop(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
     let KclValue::HomArray { value: values, ty } = array else {
         let meta = vec![args.source_range];
         let actual_type = array.human_friendly_type();
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            source_ranges: meta,
+            format!("You can't pop from a value of type {actual_type}, only an array"),
-            message: format!("You can't pop from a value of type {actual_type}, only an array"),
+            meta,
-        }));
+        )));
     };
 
     let new_array = inner_pop(values, &args)?;
@@ -173,10 +173,10 @@ pub async fn pop(_exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
 
 fn inner_pop(array: Vec<KclValue>, args: &Args) -> Result<Vec<KclValue>, KclError> {
     if array.is_empty() {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: "Cannot pop from an empty array".to_string(),
+            "Cannot pop from an empty array".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Create a new array with all elements except the last one

rust/kcl-lib/src/std/assert.rs

@@ -12,10 +12,10 @@ use crate::{
 
 async fn _assert(value: bool, message: &str, args: &Args) -> Result<(), KclError> {
     if !value {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: format!("assert failed: {}", message),
+            format!("assert failed: {}", message),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
     Ok(())
 }
@@ -111,19 +111,18 @@ async fn inner_assert(
     .iter()
     .all(|cond| cond.is_none());
     if no_condition_given {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: "You must provide at least one condition in this assert (for example, isEqualTo)".to_owned(),
+            "You must provide at least one condition in this assert (for example, isEqualTo)".to_owned(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     if tolerance.is_some() && is_equal_to.is_none() {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message:
+            "The `tolerance` arg is only used with `isEqualTo`. Either remove `tolerance` or add an `isEqualTo` arg."
-                "The `tolerance` arg is only used with `isEqualTo`. Either remove `tolerance` or add an `isEqualTo` arg."
+                .to_owned(),
-                    .to_owned(),
+            vec![args.source_range],
-            source_ranges: vec![args.source_range],
+        )));
-        }));
     }
 
     let suffix = if let Some(err_string) = error {

rust/kcl-lib/src/std/chamfer.rs

@@ -41,10 +41,10 @@ async fn inner_chamfer(
     // If you try and tag multiple edges with a tagged chamfer, we want to return an
     // error to the user that they can only tag one edge at a time.
     if tag.is_some() && tags.len() > 1 {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: "You can only tag one edge at a time with a tagged chamfer. Either delete the tag for the chamfer fn if you don't need it OR separate into individual chamfer functions for each tag.".to_string(),
+            "You can only tag one edge at a time with a tagged chamfer. Either delete the tag for the chamfer fn if you don't need it OR separate into individual chamfer functions for each tag.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let mut solid = solid.clone();

rust/kcl-lib/src/std/clone.rs

@@ -84,10 +84,10 @@ async fn inner_clone(
     fix_tags_and_references(&mut new_geometry, old_id, exec_state, &args)
         .await
         .map_err(|e| {
-            KclError::Internal(KclErrorDetails {
+            KclError::Internal(KclErrorDetails::new(
-                message: format!("failed to fix tags and references: {:?}", e),
+                format!("failed to fix tags and references: {:?}", e),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            })
+            ))
         })?;
 
     Ok(new_geometry)

rust/kcl-lib/src/std/csg.rs

@@ -24,10 +24,10 @@ pub async fn union(exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
     let tolerance: Option<TyF64> = args.get_kw_arg_opt_typed("tolerance", &RuntimeType::length(), exec_state)?;
 
     if solids.len() < 2 {
-        return Err(KclError::UndefinedValue(KclErrorDetails {
+        return Err(KclError::UndefinedValue(KclErrorDetails::new(
-            message: "At least two solids are required for a union operation.".to_string(),
+            "At least two solids are required for a union operation.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let solids = inner_union(solids, tolerance, exec_state, args).await?;
@@ -147,10 +147,10 @@ pub(crate) async fn inner_union(
         modeling_response: OkModelingCmdResponse::BooleanUnion(BooleanUnion { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
+        return Err(KclError::Internal(KclErrorDetails::new(
-            message: "Failed to get the result of the union operation.".to_string(),
+            "Failed to get the result of the union operation.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     // If we have more solids, set those as well.
@@ -169,10 +169,10 @@ pub async fn intersect(exec_state: &mut ExecState, args: Args) -> Result<KclValu
     let tolerance: Option<TyF64> = args.get_kw_arg_opt_typed("tolerance", &RuntimeType::length(), exec_state)?;
 
     if solids.len() < 2 {
-        return Err(KclError::UndefinedValue(KclErrorDetails {
+        return Err(KclError::UndefinedValue(KclErrorDetails::new(
-            message: "At least two solids are required for an intersect operation.".to_string(),
+            "At least two solids are required for an intersect operation.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let solids = inner_intersect(solids, tolerance, exec_state, args).await?;
@@ -273,10 +273,10 @@ pub(crate) async fn inner_intersect(
         modeling_response: OkModelingCmdResponse::BooleanIntersection(BooleanIntersection { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
+        return Err(KclError::Internal(KclErrorDetails::new(
-            message: "Failed to get the result of the intersection operation.".to_string(),
+            "Failed to get the result of the intersection operation.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     // If we have more solids, set those as well.
@@ -397,10 +397,10 @@ pub(crate) async fn inner_subtract(
         modeling_response: OkModelingCmdResponse::BooleanSubtract(BooleanSubtract { extra_solid_ids }),
     } = result
     else {
-        return Err(KclError::Internal(KclErrorDetails {
+        return Err(KclError::Internal(KclErrorDetails::new(
-            message: "Failed to get the result of the subtract operation.".to_string(),
+            "Failed to get the result of the subtract operation.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     // If we have more solids, set those as well.

rust/kcl-lib/src/std/edge.rs

@@ -87,10 +87,10 @@ async fn inner_get_opposite_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetOppositeEdge(opposite_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
+        return Err(KclError::Engine(KclErrorDetails::new(
-            message: format!("mcmd::Solid3dGetOppositeEdge response was not as expected: {:?}", resp),
+            format!("mcmd::Solid3dGetOppositeEdge response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     Ok(opposite_edge.edge)
@@ -172,20 +172,20 @@ async fn inner_get_next_adjacent_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetNextAdjacentEdge(adjacent_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
+        return Err(KclError::Engine(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "mcmd::Solid3dGetNextAdjacentEdge response was not as expected: {:?}",
                 resp
             ),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     adjacent_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
+        KclError::Type(KclErrorDetails::new(
-            message: format!("No edge found next adjacent to tag: `{}`", edge.value),
+            format!("No edge found next adjacent to tag: `{}`", edge.value),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        })
+        ))
     })
 }
 
@@ -264,20 +264,20 @@ async fn inner_get_previous_adjacent_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetPrevAdjacentEdge(adjacent_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
+        return Err(KclError::Engine(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "mcmd::Solid3dGetPrevAdjacentEdge response was not as expected: {:?}",
                 resp
             ),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     adjacent_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
+        KclError::Type(KclErrorDetails::new(
-            message: format!("No edge found previous adjacent to tag: `{}`", edge.value),
+            format!("No edge found previous adjacent to tag: `{}`", edge.value),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        })
+        ))
     })
 }
 
@@ -336,10 +336,10 @@ async fn inner_get_common_edge(
     }
 
     if faces.len() != 2 {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: "getCommonEdge requires exactly two tags for faces".to_string(),
+            "getCommonEdge requires exactly two tags for faces".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
     let first_face_id = args.get_adjacent_face_to_tag(exec_state, &faces[0], false).await?;
     let second_face_id = args.get_adjacent_face_to_tag(exec_state, &faces[1], false).await?;
@@ -348,10 +348,10 @@ async fn inner_get_common_edge(
     let second_tagged_path = args.get_tag_engine_info(exec_state, &faces[1])?;
 
     if first_tagged_path.sketch != second_tagged_path.sketch {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: "getCommonEdge requires the faces to be in the same original sketch".to_string(),
+            "getCommonEdge requires the faces to be in the same original sketch".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Flush the batch for our fillets/chamfers if there are any.
@@ -377,19 +377,19 @@ async fn inner_get_common_edge(
         modeling_response: OkModelingCmdResponse::Solid3dGetCommonEdge(common_edge),
     } = &resp
     else {
-        return Err(KclError::Engine(KclErrorDetails {
+        return Err(KclError::Engine(KclErrorDetails::new(
-            message: format!("mcmd::Solid3dGetCommonEdge response was not as expected: {:?}", resp),
+            format!("mcmd::Solid3dGetCommonEdge response was not as expected: {:?}", resp),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     };
 
     common_edge.edge.ok_or_else(|| {
-        KclError::Type(KclErrorDetails {
+        KclError::Type(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "No common edge was found between `{}` and `{}`",
                 faces[0].value, faces[1].value
             ),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        })
+        ))
     })
 }

rust/kcl-lib/src/std/extrude.rs

@@ -175,11 +175,11 @@ async fn inner_extrude(
     let mut solids = Vec::new();
 
     if symmetric.unwrap_or(false) && bidirectional_length.is_some() {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            source_ranges: vec![args.source_range],
+            "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
-            message: "You cannot give both `symmetric` and `bidirectional` params, you have to choose one or the other"
                 .to_owned(),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let bidirection = bidirectional_length.map(|l| LengthUnit(l.to_mm()));
@@ -262,10 +262,10 @@ pub(crate) async fn do_post_extrude<'a>(
         // The "get extrusion face info" API call requires *any* edge on the sketch being extruded.
         // So, let's just use the first one.
         let Some(any_edge_id) = sketch.paths.first().map(|edge| edge.get_base().geo_meta.id) else {
-            return Err(KclError::Type(KclErrorDetails {
+            return Err(KclError::Type(KclErrorDetails::new(
-                message: "Expected a non-empty sketch".to_string(),
+                "Expected a non-empty sketch".to_owned(),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            }));
+            )));
         };
         any_edge_id
     };
@@ -387,13 +387,13 @@ pub(crate) async fn do_post_extrude<'a>(
     // Add the tags for the start or end caps.
     if let Some(tag_start) = named_cap_tags.start {
         let Some(start_cap_id) = start_cap_id else {
-            return Err(KclError::Type(KclErrorDetails {
+            return Err(KclError::Type(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "Expected a start cap ID for tag `{}` for extrusion of sketch {:?}",
                     tag_start.name, sketch.id
                 ),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            }));
+            )));
         };
 
         new_value.push(ExtrudeSurface::ExtrudePlane(crate::execution::ExtrudePlane {
@@ -407,13 +407,13 @@ pub(crate) async fn do_post_extrude<'a>(
     }
     if let Some(tag_end) = named_cap_tags.end {
         let Some(end_cap_id) = end_cap_id else {
-            return Err(KclError::Type(KclErrorDetails {
+            return Err(KclError::Type(KclErrorDetails::new(
-                message: format!(
+                format!(
                     "Expected an end cap ID for tag `{}` for extrusion of sketch {:?}",
                     tag_end.name, sketch.id
                 ),
-                source_ranges: vec![args.source_range],
+                vec![args.source_range],
-            }));
+            )));
         };
 
         new_value.push(ExtrudeSurface::ExtrudePlane(crate::execution::ExtrudePlane {

rust/kcl-lib/src/std/fillet.rs

@@ -49,10 +49,11 @@ pub(super) fn validate_unique<T: Eq + std::hash::Hash>(tags: &[(T, SourceRange)]
         }
     }
     if !duplicate_tags_source.is_empty() {
-        return Err(KclError::Type(KclErrorDetails {
+        return Err(KclError::Type(KclErrorDetails::new(
-            message: "The same edge ID is being referenced multiple times, which is not allowed. Please select a different edge".to_string(),
+            "The same edge ID is being referenced multiple times, which is not allowed. Please select a different edge"
-            source_ranges: duplicate_tags_source,
+                .to_string(),
-        }));
+            duplicate_tags_source,
+        )));
     }
     Ok(())
 }

rust/kcl-lib/src/std/helix.rs

@@ -6,7 +6,7 @@ use kittycad_modeling_cmds::{self as kcmc, shared::Point3d};
 
 use super::args::TyF64;
 use crate::{
-    errors::KclError,
+    errors::{KclError, KclErrorDetails},
     execution::{
         types::{PrimitiveType, RuntimeType},
         ExecState, Helix as HelixValue, KclValue, Solid,
@@ -33,50 +33,50 @@ pub async fn helix(exec_state: &mut ExecState, args: Args) -> Result<KclValue, K
 
     // Make sure we have a radius if we don't have a cylinder.
     if radius.is_none() && cylinder.is_none() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Radius is required when creating a helix without a cylinder.".to_string(),
+            "Radius is required when creating a helix without a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Make sure we don't have a radius if we have a cylinder.
     if radius.is_some() && cylinder.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Radius is not allowed when creating a helix with a cylinder.".to_string(),
+            "Radius is not allowed when creating a helix with a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Make sure we have an axis if we don't have a cylinder.
     if axis.is_none() && cylinder.is_none() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Axis is required when creating a helix without a cylinder.".to_string(),
+            "Axis is required when creating a helix without a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Make sure we don't have an axis if we have a cylinder.
     if axis.is_some() && cylinder.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Axis is not allowed when creating a helix with a cylinder.".to_string(),
+            "Axis is not allowed when creating a helix with a cylinder.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Make sure we have a radius if we have an axis.
     if radius.is_none() && axis.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Radius is required when creating a helix around an axis.".to_string(),
+            "Radius is required when creating a helix around an axis.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     // Make sure we have an axis if we have a radius.
     if axis.is_none() && radius.is_some() {
-        return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+        return Err(KclError::Semantic(crate::errors::KclErrorDetails::new(
-            message: "Axis is required when creating a helix around an axis.".to_string(),
+            "Axis is required when creating a helix around an axis.".to_string(),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let value = inner_helix(
@@ -140,10 +140,10 @@ async fn inner_helix(
             Axis3dOrEdgeReference::Axis { direction, origin } => {
                 // Make sure they gave us a length.
                 let Some(length) = length else {
-                    return Err(KclError::Semantic(crate::errors::KclErrorDetails {
+                    return Err(KclError::Semantic(KclErrorDetails::new(
-                        message: "Length is required when creating a helix around an axis.".to_string(),
+                        "Length is required when creating a helix around an axis.".to_owned(),
-                        source_ranges: vec![args.source_range],
+                        vec![args.source_range],
-                    }));
+                    )));
                 };
 
                 args.batch_modeling_cmd(

rust/kcl-lib/src/std/loft.rs

@@ -148,13 +148,13 @@ async fn inner_loft(
 ) -> Result<Box<Solid>, KclError> {
     // Make sure we have at least two sketches.
     if sketches.len() < 2 {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            message: format!(
+            format!(
                 "Loft requires at least two sketches, but only {} were provided.",
                 sketches.len()
             ),
-            source_ranges: vec![args.source_range],
+            vec![args.source_range],
-        }));
+        )));
     }
 
     let id = exec_state.next_uuid();

rust/kcl-lib/src/std/math.rs

@@ -56,13 +56,13 @@ pub async fn sqrt(exec_state: &mut ExecState, args: Args) -> Result<KclValue, Kc
     let input: TyF64 = args.get_unlabeled_kw_arg_typed("input", &RuntimeType::num_any(), exec_state)?;
 
     if input.n < 0.0 {
-        return Err(KclError::Semantic(KclErrorDetails {
+        return Err(KclError::Semantic(KclErrorDetails::new(
-            source_ranges: vec![args.source_range],
+            format!(
-            message: format!(
                 "Attempt to take square root (`sqrt`) of a number less than zero ({})",
                 input.n
             ),
-        }));
+            vec![args.source_range],
+        )));
     }
 
     let result = input.n.sqrt();