test(files): cover the code-highlight incremental re-tokenization gate

Export and unit-test changeTouchesCodeBlock: prose-only edits map decorations
(false), edits inside a code block or a setNodeMarkup language change re-tokenize
(true) — the perf-correctness path that keeps highlighting off the keystroke path.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/code-highlight.test.ts

@@ -3,11 +3,22 @@
  */
 import { Editor } from '@tiptap/core'
 import { afterEach, describe, expect, it } from 'vitest'
-import { buildDecorations } from './code-highlight'
+import { buildDecorations, changeTouchesCodeBlock } from './code-highlight'
 import { createMarkdownContentExtensions } from './extensions'
 
 let editor: Editor | null = null
 
+/** Position just inside the first code block in the current editor doc. */
+function codeBlockPos(ed: Editor): number {
+  let pos = -1
+  ed.state.doc.descendants((node, p) => {
+    if (pos === -1 && node.type.name === 'codeBlock') pos = p
+    return pos === -1
+  })
+  if (pos === -1) throw new Error('no code block')
+  return pos
+}
+
 function decorationClassesFor(markdown: string): string[] {
   editor = new Editor({ extensions: createMarkdownContentExtensions() })
   editor.commands.setContent(markdown, { contentType: 'markdown' })
@@ -41,3 +52,30 @@ describe('code block syntax highlighting', () => {
     expect(decorationClassesFor('```unregistered-lang\n+++ foo\n```')).toHaveLength(0)
   })
 })
+
+describe('changeTouchesCodeBlock (incremental re-tokenization gate)', () => {
+  function mount(markdown: string): Editor {
+    editor = new Editor({ extensions: createMarkdownContentExtensions() })
+    editor.commands.setContent(markdown, { contentType: 'markdown' })
+    return editor
+  }
+
+  it('is false when an edit lands only in prose (decorations are mapped, not rebuilt)', () => {
+    const ed = mount('intro text\n\n```js\nconst x = 1\n```')
+    const tr = ed.state.tr.insertText('Z', 1) // inside the leading paragraph
+    expect(changeTouchesCodeBlock(tr, tr.doc)).toBe(false)
+  })
+
+  it('is true when an edit lands inside a code block (forces a re-tokenize)', () => {
+    const ed = mount('intro\n\n```js\nconst x = 1\n```')
+    const tr = ed.state.tr.insertText('y', codeBlockPos(ed) + 1)
+    expect(changeTouchesCodeBlock(tr, tr.doc)).toBe(true)
+  })
+
+  it('is true when the code block language changes via setNodeMarkup', () => {
+    const ed = mount('```js\nconst x = 1\n```')
+    const pos = codeBlockPos(ed)
+    const tr = ed.state.tr.setNodeMarkup(pos, undefined, { language: 'python' })
+    expect(changeTouchesCodeBlock(tr, tr.doc)).toBe(true)
+  })
+})

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/code-highlight.ts

@@ -85,7 +85,7 @@ export function buildDecorations(doc: ProseMirrorNode): DecorationSet {
  * a `setNodeMarkup` language change (whose step range covers the node). When false, the cheap
  * path just maps existing decorations instead of re-tokenizing.
  */
-function changeTouchesCodeBlock(tr: Transaction, doc: ProseMirrorNode): boolean {
+export function changeTouchesCodeBlock(tr: Transaction, doc: ProseMirrorNode): boolean {
   let touches = false
   for (const map of tr.mapping.maps) {
     map.forEach((_oldStart, _oldEnd, newStart, newEnd) => {