Clear the AST if there was a parse error. (#2706)

Clear the AST if there was a parse error.

This leads to an unfortunate loop (good -> invalid -> original) that
wouldn't clear the diagnostics from the invalid step.

e2e/playwright/flow-tests.spec.ts

@@ -594,6 +594,41 @@ test('if you write kcl with lint errors you get lints', async ({ page }) => {
   await expect(page.locator('.cm-lint-marker-info')).not.toBeVisible()
 })
 
+test('if you fixup kcl errors you clear lints', async ({ page }) => {
+  const u = await getUtils(page)
+  await page.addInitScript(async () => {
+    localStorage.setItem(
+      'persistCode',
+      `const sketch001 = startSketchOn('XZ')
+|> startProfileAt([3.29, 7.86], %)
+|> line([2.48, 2.44], %)
+|> line([2.66, 1.17], %)
+|> close(%)
+`
+    )
+  })
+
+  await page.setViewportSize({ width: 1000, height: 500 })
+  await page.goto('/')
+
+  await u.waitForAuthSkipAppStart()
+
+  // check no error to begin with
+  await expect(page.locator('.cm-lint-marker-error')).not.toBeVisible()
+
+  await u.codeLocator.click()
+
+  await page.getByText(' |> line([2.48, 2.44], %)').click()
+
+  await expect(page.locator('.cm-lint-marker-error')).not.toBeVisible()
+  await page.keyboard.press('End')
+  await page.keyboard.press('Backspace')
+
+  await expect(page.locator('.cm-lint-marker-error')).toBeVisible()
+  await page.keyboard.type(')')
+  await expect(page.locator('.cm-lint-marker-error')).not.toBeVisible()
+})
+
 test('if you write invalid kcl you get inlined errors', async ({ page }) => {
   const u = await getUtils(page)
   await page.setViewportSize({ width: 1000, height: 500 })

src/lang/KclSingleton.ts

@@ -41,7 +41,10 @@ export class KclManager {
   engineCommandManager: EngineCommandManager
   private _defferer = deferExecution((code: string) => {
     const ast = this.safeParse(code)
-    if (!ast) return
+    if (!ast) {
+      this.clearAst()
+      return
+    }
     try {
       const fmtAndStringify = (ast: Program) =>
         JSON.stringify(parse(recast(ast)))
@@ -146,6 +149,18 @@ export class KclManager {
     this._executeCallback = callback
   }
 
+  clearAst() {
+    this._ast = {
+      body: [],
+      start: 0,
+      end: 0,
+      nonCodeMeta: {
+        nonCodeNodes: {},
+        start: [],
+      },
+    }
+  }
+
   safeParse(code: string): Program | null {
     try {
       const ast = parse(code)
@@ -293,14 +308,20 @@ export class KclManager {
     if (!force) return this._defferer(codeManager.code)
 
     const ast = this.safeParse(codeManager.code)
-    if (!ast) return
+    if (!ast) {
+      this.clearAst()
+      return
+    }
     this.ast = { ...ast }
     return this.executeAst(ast, zoomToFit)
   }
   format() {
     const originalCode = codeManager.code
     const ast = this.safeParse(originalCode)
-    if (!ast) return
+    if (!ast) {
+      this.clearAst()
+      return
+    }
     const code = recast(ast)
     if (originalCode === code) return