fix(files): fix large file editor performance and selection toolbar placement

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/menus/use-bubble-menu-floating.test.ts

@@ -0,0 +1,34 @@
+/**
+ * @vitest-environment node
+ */
+import { Schema } from '@tiptap/pm/model'
+import { AllSelection, TextSelection } from '@tiptap/pm/state'
+import { describe, expect, it } from 'vitest'
+import { bubbleMenuAnchorRange } from '@/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/menus/use-bubble-menu-floating'
+
+const schema = new Schema({
+  nodes: {
+    doc: { content: 'paragraph+' },
+    paragraph: { content: 'text*' },
+    text: { inline: true },
+  },
+})
+
+const doc = schema.node('doc', null, [schema.node('paragraph', null, schema.text('first line'))])
+
+describe('bubbleMenuAnchorRange', () => {
+  it('collapses a whole-document selection to its leading position', () => {
+    const selection = new AllSelection(doc)
+
+    expect(bubbleMenuAnchorRange(selection)).toEqual({
+      from: selection.from,
+      to: selection.from,
+    })
+  })
+
+  it('preserves ordinary text-selection geometry', () => {
+    const selection = TextSelection.create(doc, 1, 6)
+
+    expect(bubbleMenuAnchorRange(selection)).toEqual({ from: 1, to: 6 })
+  })
+})

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/rich-markdown-editor/menus/use-bubble-menu-floating.ts

@@ -1,7 +1,18 @@
 import { useCallback } from 'react'
 import { posToDOMRect } from '@tiptap/core'
+import { AllSelection, type Selection } from '@tiptap/pm/state'
 import type { Editor } from '@tiptap/react'
 
+/**
+ * A whole-document selection has a viewport-sized bounding box, which gives Floating UI no viable
+ * side to flip to and leaves the toolbar clipped above the editor. Anchor that semantic selection to
+ * the document's leading position; every ordinary selection keeps its complete range geometry.
+ */
+export function bubbleMenuAnchorRange(selection: Selection): { from: number; to: number } {
+  if (selection instanceof AllSelection) return { from: selection.from, to: selection.from }
+  return { from: selection.from, to: selection.to }
+}
+
 /**
  * A Floating UI virtual element anchored to the current selection. The rect is recomputed on every
  * call rather than cached by selection: the same `from`/`to` maps to a different screen position as
@@ -11,7 +22,7 @@ import type { Editor } from '@tiptap/react'
 function selectionVirtualElement(editor: Editor) {
   const { view, state } = editor
   if (!view.dom.isConnected) return null
-  const { from, to } = state.selection
+  const { from, to } = bubbleMenuAnchorRange(state.selection)
   const rect = posToDOMRect(view, from, to)
   return {
     getBoundingClientRect: () => rect,

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/text-editor-sync.test.tsx

@@ -0,0 +1,153 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { act, type ComponentProps } from 'react'
+import { createRoot, type Root } from 'react-dom/client'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import type { WorkspaceFileRecord } from '@/lib/uploads/contexts/workspace'
+import { TextEditor } from '@/app/workspace/[workspaceId]/files/components/file-viewer/text-editor'
+
+interface MockMonacoProps {
+  onChange?: (value: string | undefined) => void
+  onMount?: (editor: unknown, monaco: unknown) => void
+  options?: unknown
+}
+
+const state = vi.hoisted(() => ({
+  content: 'initial',
+  editorProps: null as MockMonacoProps | null,
+}))
+
+vi.mock('next/dynamic', () => ({
+  default: () => (props: MockMonacoProps) => {
+    state.editorProps = props
+    return <div data-testid='monaco-editor' />
+  },
+}))
+
+vi.mock(
+  '@/app/workspace/[workspaceId]/files/components/file-viewer/use-editable-file-content',
+  () => ({
+    useEditableFileContent: () => ({
+      content: state.content,
+      setDraftContent: (content: string) => {
+        state.content = content
+      },
+      isStreamInteractionLocked: false,
+      isContentLoading: false,
+      hasContentError: false,
+      saveImmediately: vi.fn(),
+    }),
+  })
+)
+
+vi.mock(
+  '@/app/workspace/[workspaceId]/files/components/file-viewer/use-selection-copy-bridge',
+  () => ({ useSelectionCopyBridge: vi.fn() })
+)
+
+vi.mock('@/hooks/use-add-to-chat', () => ({ useAddToChat: () => vi.fn() }))
+
+const file: WorkspaceFileRecord = {
+  id: 'file-1',
+  workspaceId: 'workspace-1',
+  name: 'example.txt',
+  key: 'workspace/file-1',
+  path: '/workspace/file-1',
+  size: 7,
+  type: 'text/plain',
+  uploadedBy: 'user-1',
+  uploadedAt: new Date('2026-01-01T00:00:00.000Z'),
+  updatedAt: new Date('2026-01-01T00:00:00.000Z'),
+}
+
+const props: ComponentProps<typeof TextEditor> = {
+  file,
+  workspaceId: file.workspaceId,
+  canEdit: true,
+  previewMode: 'editor',
+  disableStreamingAutoScroll: false,
+}
+
+function createEditor() {
+  let editorValue = 'initial'
+  const getValue = vi.fn(() => editorValue)
+  const applyEdits = vi.fn((edits: Array<{ text: string }>) => {
+    editorValue = edits[0]?.text ?? editorValue
+  })
+  const model = {
+    getValue,
+    setValue: vi.fn((value: string) => {
+      editorValue = value
+    }),
+    applyEdits,
+    getFullModelRange: vi.fn(() => ({})),
+  }
+  const editor = {
+    getModel: vi.fn(() => model),
+    addCommand: vi.fn(),
+    getSelection: vi.fn(() => null),
+    onContextMenu: vi.fn(() => ({ dispose: vi.fn() })),
+    onDidDispose: vi.fn(),
+  }
+  const monaco = {
+    KeyMod: { CtrlCmd: 1 },
+    KeyCode: { KeyS: 2 },
+  }
+
+  return { editor, monaco, model, getValue, applyEdits }
+}
+
+function renderEditor(): { rerender: () => void; root: Root } {
+  const root = createRoot(document.createElement('div'))
+  act(() => root.render(<TextEditor {...props} />))
+  return {
+    rerender: () => act(() => root.render(<TextEditor {...props} file={{ ...file }} />)),
+    root,
+  }
+}
+
+describe('TextEditor content synchronization', () => {
+  beforeEach(() => {
+    ;(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true
+    state.content = 'initial'
+    state.editorProps = null
+  })
+
+  it('does not reread the complete Monaco model after a local edit', () => {
+    const view = renderEditor()
+    const { editor, monaco, getValue } = createEditor()
+
+    act(() => {
+      state.editorProps?.onMount?.(editor, monaco)
+    })
+    const initialOptions = state.editorProps?.options
+    getValue.mockClear()
+
+    act(() => {
+      state.editorProps?.onChange?.('local edit')
+    })
+    view.rerender()
+
+    expect(getValue).not.toHaveBeenCalled()
+    expect(state.editorProps?.options).toBe(initialOptions)
+    act(() => view.root.unmount())
+  })
+
+  it('still reconciles an external update when the editor has no local changes', () => {
+    const view = renderEditor()
+    const { editor, monaco, getValue, applyEdits } = createEditor()
+
+    act(() => {
+      state.editorProps?.onMount?.(editor, monaco)
+    })
+    getValue.mockClear()
+
+    state.content = 'server update'
+    view.rerender()
+
+    expect(getValue).toHaveBeenCalledOnce()
+    expect(applyEdits).toHaveBeenCalledWith([{ range: {}, text: 'server update' }])
+    act(() => view.root.unmount())
+  })
+})

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/text-editor.tsx

@@ -5,6 +5,7 @@ import {
   type ClipboardEvent as ReactClipboardEvent,
   useCallback,
   useEffect,
+  useMemo,
   useRef,
   useState,
 } from 'react'
@@ -33,6 +34,44 @@ import { useSelectionCopyBridge } from './use-selection-copy-bridge'
 /** File ids observed rendering as Sim pages this session (see the sticky lock). */
 const KNOWN_PAGE_FILE_IDS = new Set<string>()
 
+const TEXT_EDITOR_OPTIONS = {
+  largeFileOptimizations: true,
+  maxTokenizationLineLength: 20_000,
+  minimap: { enabled: false },
+  scrollBeyondLastLine: false,
+  wordWrap: 'on',
+  fontSize: 13,
+  lineNumbers: 'on',
+  padding: { top: 24, bottom: 24 },
+  fontFamily:
+    'ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace',
+  tabSize: 2,
+  automaticLayout: true,
+  renderLineHighlight: 'line',
+  occurrencesHighlight: 'singleFile',
+  overviewRulerLanes: 0,
+  hideCursorInOverviewRuler: true,
+  scrollbar: {
+    verticalScrollbarSize: 6,
+    horizontalScrollbarSize: 6,
+  },
+  quickSuggestions: false,
+  suggestOnTriggerCharacters: false,
+  wordBasedSuggestions: 'currentDocument',
+  parameterHints: { enabled: false },
+  codeLens: false,
+  lightbulb: {
+    enabled: 'off' as MonacoEditorTypes.ShowLightbulbIconMode,
+  },
+  inlayHints: { enabled: 'off' },
+  contextmenu: false,
+  fixedOverflowWidgets: true,
+  glyphMargin: false,
+  stickyScroll: { enabled: false },
+  bracketPairColorization: { enabled: false },
+  unicodeHighlight: { ambiguousCharacters: false },
+} satisfies MonacoEditorTypes.IStandaloneEditorConstructionOptions
+
 const SIM_DARK_RULES: MonacoEditorTypes.ITokenThemeRule[] = [
   { token: 'comment', foreground: '606060', fontStyle: 'italic' },
   { token: 'string', foreground: '3ab872' },
@@ -382,6 +421,7 @@ export const TextEditor = memo(function TextEditor({
 }: TextEditorProps) {
   const containerRef = useRef<HTMLDivElement>(null)
   const monacoEditorRef = useRef<Parameters<OnMount>[0] | null>(null)
+  const lastEditorValueRef = useRef('')
   const lastSyncedContentRef = useRef('')
   const hasAutoFocusedRef = useRef(false)
   const contentRef = useRef('')
@@ -456,11 +496,14 @@ export const TextEditor = memo(function TextEditor({
   useSelectionCopyBridge(containerRef, buildSelectionContext, !isContentLoading)
 
   useEffect(() => {
+    if (lastEditorValueRef.current === content) return
+
     const editor = monacoEditorRef.current
     if (!editor) return
     const model = editor.getModel()
     if (!model) return
     const monacoValue = model.getValue()
+    lastEditorValueRef.current = monacoValue
     if (monacoValue === content) return
 
     if (isStreamInteractionLocked || monacoValue === lastSyncedContentRef.current) {
@@ -491,6 +534,7 @@ export const TextEditor = memo(function TextEditor({
         model.applyEdits([{ range: model.getFullModelRange(), text: content }])
       }
       suppressScrollListenerRef.current = false
+      lastEditorValueRef.current = content
       lastSyncedContentRef.current = content
     }
   }, [content, isStreamInteractionLocked])
@@ -563,9 +607,12 @@ export const TextEditor = memo(function TextEditor({
 
     const model = editor.getModel()
     const currentContent = contentRef.current
-    if (model && currentContent && model.getValue() !== currentContent) {
-      model.setValue(currentContent)
+    if (model) {
+      if (model.getValue() !== currentContent) {
+        model.setValue(currentContent)
+      }
       lastSyncedContentRef.current = currentContent
+      lastEditorValueRef.current = currentContent
     }
 
     if (autoFocus && !hasAutoFocusedRef.current) {
@@ -588,6 +635,7 @@ export const TextEditor = memo(function TextEditor({
   const handleEditorChange = useCallback(
     (value: string | undefined) => {
       const nextValue = value ?? ''
+      lastEditorValueRef.current = nextValue
       contentRef.current = nextValue
       setDraftContent(nextValue)
     },
@@ -633,6 +681,10 @@ export const TextEditor = memo(function TextEditor({
 
   const isStreaming = isStreamInteractionLocked
   const isEditorReadOnly = isStreamInteractionLocked || !canEdit
+  const editorOptions = useMemo(
+    () => ({ ...TEXT_EDITOR_OPTIONS, readOnly: isEditorReadOnly }),
+    [isEditorReadOnly]
+  )
 
   const previewType = resolvePreviewType(file.type, file.name)
   const isIframeRendered = previewType === 'html' || previewType === 'svg'
@@ -697,44 +749,7 @@ export const TextEditor = memo(function TextEditor({
             defaultValue={content}
             language={monacoLanguage}
             theme={monacoTheme}
-            options={{
-              readOnly: isEditorReadOnly,
-              largeFileOptimizations: true,
-              maxTokenizationLineLength: 20_000,
-              minimap: { enabled: false },
-              scrollBeyondLastLine: false,
-              wordWrap: 'on',
-              fontSize: 13,
-              lineNumbers: 'on',
-              padding: { top: 24, bottom: 24 },
-              fontFamily:
-                'ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace',
-              tabSize: 2,
-              automaticLayout: true,
-              renderLineHighlight: 'line',
-              occurrencesHighlight: 'singleFile',
-              overviewRulerLanes: 0,
-              hideCursorInOverviewRuler: true,
-              scrollbar: {
-                verticalScrollbarSize: 6,
-                horizontalScrollbarSize: 6,
-              },
-              quickSuggestions: false,
-              suggestOnTriggerCharacters: false,
-              wordBasedSuggestions: 'currentDocument',
-              parameterHints: { enabled: false },
-              codeLens: false,
-              lightbulb: {
-                enabled: 'off' as MonacoEditorTypes.ShowLightbulbIconMode,
-              },
-              inlayHints: { enabled: 'off' },
-              contextmenu: false,
-              fixedOverflowWidgets: true,
-              glyphMargin: false,
-              stickyScroll: { enabled: false },
-              bracketPairColorization: { enabled: false },
-              unicodeHighlight: { ambiguousCharacters: false },
-            }}
+            options={editorOptions}
             onChange={handleEditorChange}
             onMount={handleEditorMount}
             className='h-full'