Allow deletion of only item in AST (#6335)

* Update test to check for deletion of only operation

* Allow updateEditorWithAstAndWriteToFile to clear AST

* Update src/lang/codeManager.ts

Co-authored-by: Jonathan Tran <jonnytran@gmail.com>

* Weave `isDeleting` through to `deleteSelectionPromise`

* fmt

---------

Co-authored-by: Jonathan Tran <jonnytran@gmail.com>
Co-authored-by: Pierre Jacquier <pierrejacquier39@gmail.com>

e2e/playwright/feature-tree-pane.spec.ts

@@ -430,5 +430,17 @@ profile003 = startProfileAt([0, -4.93], sketch001)
       await editor.expectEditor.not.toContain('sketch001 =')
       await editor.expectEditor.not.toContain('profile002 = ')
     })
+
+    await test.step(`Delete the remaining plane via feature tree`, async () => {
+      const operationButton = await toolbar.getFeatureTreeOperation(
+        'Offset Plane',
+        0
+      )
+      await operationButton.click({ button: 'left' })
+      await page.keyboard.press('Delete')
+
+      // Verify the plane code is gone, and https://github.com/KittyCAD/modeling-app/issues/5988 is fixed.
+      await editor.expectEditor.not.toContain('plane001 =')
+    })
   })
 })

src/lang/codeManager.ts

@@ -165,13 +165,16 @@ export default class CodeManager {
     }
   }
 
-  async updateEditorWithAstAndWriteToFile(ast: Program) {
+  async updateEditorWithAstAndWriteToFile(
+    ast: Program,
+    options?: Partial<{ isDeleting: boolean }>
+  ) {
     // We clear the AST when it cannot be parsed. If we are trying to write an
     // empty AST, it's probably because of an earlier error. That's a bad state
     // to be in, and it's not going to be pretty, but at the least, let's not
-    // permanently delete the user's code. If you want to clear the scene, call
-    // updateCodeStateEditor directly.
-    if (ast.body.length === 0) return
+    // permanently delete the user's code accidentally.
+    // if you want to clear the scene, pass in the `isDeleting` option.
+    if (ast.body.length === 0 && !options?.isDeleting) return
     const newCode = recast(ast)
     if (err(newCode)) return
     // Test to see if we can parse the recast code, and never update the editor with bad code.

src/lang/modelingWorkflows.ts

@@ -54,6 +54,7 @@ export async function updateModelingState(
   },
   options?: {
     focusPath?: Array<PathToNode>
+    isDeleting?: boolean
   }
 ): Promise<void> {
   let updatedAst: {
@@ -69,7 +70,10 @@ export async function updateModelingState(
 
   // Step 2: Update the code editor and save file
   await dependencies.codeManager.updateEditorWithAstAndWriteToFile(
-    updatedAst.newAst
+    updatedAst.newAst,
+    {
+      isDeleting: options?.isDeleting,
+    }
   )
 
   // Step 3: Set focus on the newly added code if needed

src/lang/modifyAst/deleteSelection.ts

@@ -38,9 +38,16 @@ export async function deleteSelectionPromise(
   if (testExecute.errors.length) {
     return new Error(deletionErrorMessage)
   }
-  await updateModelingState(modifiedAst, EXECUTION_TYPE_REAL, {
+  await updateModelingState(
+    modifiedAst,
+    EXECUTION_TYPE_REAL,
+    {
       kclManager,
       editorManager,
       codeManager,
-  })
+    },
+    {
+      isDeleting: true,
+    }
+  )
 }