fix(chat): avoid false file output cards

desktop/src/components/chat/MessageList.test.tsx

@@ -5254,7 +5254,7 @@ describe('MessageList nested tool calls', () => {
     expect(await screen.findByText('blank-response.ts')).toBeTruthy()
   })
 
-  it('keeps historical turn change cards visible while the next turn is running', async () => {
+  it('keeps checkpoint evidence while hiding change cards for a running background task', async () => {
     vi.spyOn(sessionsApi, 'getTurnCheckpoints').mockResolvedValue({
       checkpoints: [
         {
@@ -5283,7 +5283,7 @@ describe('MessageList nested tool calls', () => {
       {
         id: 'assistant-1',
         type: 'assistant_text',
-        content: 'done',
+        content: '我正准备查看 test123.md',
         timestamp: 2,
       },
     ]
@@ -5297,6 +5297,7 @@ describe('MessageList nested tool calls', () => {
     render(<MessageList />)
 
     expect(await screen.findByText('first.ts')).toBeTruthy()
+    expect(screen.queryByText('Markdown')).toBeNull()
 
     act(() => {
       useChatStore.setState({
@@ -5322,6 +5323,7 @@ describe('MessageList nested tool calls', () => {
     await waitFor(() => {
       expect(screen.queryByText('first.ts')).toBeNull()
     })
+    expect(screen.queryByText('Markdown')).toBeNull()
 
     act(() => {
       useChatStore.setState({
@@ -5347,6 +5349,7 @@ describe('MessageList nested tool calls', () => {
     await waitFor(() => {
       expect(screen.getByText('first.ts')).toBeTruthy()
     })
+    expect(screen.queryByText('Markdown')).toBeNull()
   })
 
   it('does not load turn change cards while background tasks are still running', async () => {
@@ -5604,7 +5607,7 @@ describe('MessageList nested tool calls', () => {
             {
               id: 'assistant-2',
               type: 'assistant_text',
-              content: 'second done',
+              content: '我正准备查看 test123.md',
               timestamp: 4,
             },
           ],
@@ -5618,6 +5621,9 @@ describe('MessageList nested tool calls', () => {
     expect(cards).toHaveLength(1)
     expect(screen.getByText('first.ts')).toBeTruthy()
     expect(screen.queryByText('second.ts')).toBeNull()
+    await waitFor(() => {
+      expect(screen.queryByText('Markdown')).toBeNull()
+    })
   })
 
   it('shows raw startup details under translated CLI startup errors', () => {

desktop/src/components/chat/MessageList.tsx

@@ -793,6 +793,7 @@ function buildTurnCardInsertionMap(
 
   const cardsByRenderIndex = new Map<number, TurnChangeCardModel[]>()
   turnChangeCards.forEach((card) => {
+    if (card.checkpoint.code.filesChanged.length === 0) return
     const renderIndex =
       lastResponseIndexByTurnId.get(card.target.messageId) ??
       userIndexByTurnId.get(card.target.messageId)
@@ -820,9 +821,7 @@ function buildChangedFilesByRenderIndex(
 ): Map<number, string[]> {
   const filesByTurnId = new Map<string, string[]>()
   for (const card of turnChangeCards) {
-    if (card.checkpoint.code.filesChanged.length > 0) {
-      filesByTurnId.set(card.target.messageId, card.checkpoint.code.filesChanged)
-    }
+    filesByTurnId.set(card.target.messageId, card.checkpoint.code.filesChanged)
   }
   if (filesByTurnId.size === 0) return new Map()
 
@@ -2022,8 +2021,8 @@ export function MessageList({ sessionId, compact = false, mobileLayout = false }
     [renderItems, visibleTurnChangeCards],
   )
   const changedFilesByRenderIndex = useMemo(
-    () => buildChangedFilesByRenderIndex(renderItems, visibleTurnChangeCards),
-    [renderItems, visibleTurnChangeCards],
+    () => buildChangedFilesByRenderIndex(renderItems, turnChangeCards),
+    [renderItems, turnChangeCards],
   )
   const renderItemKeys = useMemo(
     () => renderItems.map(getRenderItemKey),
@@ -2170,7 +2169,7 @@ export function MessageList({ sessionId, compact = false, mobileLayout = false }
             const target =
               targetByMessageId.get(checkpoint.target.targetUserMessageId) ??
               targetByUserMessageIndex.get(checkpoint.target.userMessageIndex)
-            if (!target || !checkpoint.code.available || checkpoint.code.filesChanged.length === 0) {
+            if (!target || !checkpoint.code.available) {
               return []
             }
             return [{

desktop/src/lib/assistantOutputTargets.test.ts

@@ -333,13 +333,26 @@ describe('extractAssistantOutputTargets with changedFiles reconciliation', () =>
     })
   })
 
-  it('falls back to text-only behavior when changedFiles is empty', () => {
+  it('drops file mentions when changedFiles explicitly confirms no files changed', () => {
+    const targets = extractAssistantOutputTargets(
+      '我正准备查看 test123.md，服务地址是 http://localhost:5173/',
+      {
+        workDir: '/private/tmp',
+        changedFiles: [],
+      },
+    )
+
+    expect(targets).toHaveLength(1)
+    expect(targets).toMatchObject([
+      { kind: 'localhost-url', href: 'http://localhost:5173/' },
+    ])
+  })
+
+  it('falls back to text-only behavior when changedFiles is unavailable', () => {
     const targets = extractAssistantOutputTargets('已创建 `index.html`', {
       workDir: '/private/tmp',
-      changedFiles: [],
     })
 
-    // No reconciliation → original bare-path behavior (mention kept as-is).
     expect(targets).toMatchObject([{ kind: 'local-html', normalizedPath: 'index.html' }])
   })
 

desktop/src/lib/assistantOutputTargets.ts

@@ -32,7 +32,8 @@ export type ExtractAssistantOutputTargetOptions = {
    * file is corrected to the actual changed path (so `index.html` resolves to the
    * `todo-app/index.html` that was really written), and a mentioned file that the
    * turn never changed is dropped instead of pointing at a non-existent path.
-   * Localhost URLs are unaffected. Omitted/empty → fall back to text-only behavior.
+   * Localhost URLs are unaffected. Omitted → fall back to text-only behavior;
+   * an empty array confirms the turn changed no files, so file targets are dropped.
    */
   changedFiles?: string[]
 }
@@ -239,7 +240,7 @@ export function extractAssistantOutputTargets(
     results.push(candidate.target)
   }
 
-  if (options.changedFiles && options.changedFiles.length > 0) {
+  if (options.changedFiles !== undefined) {
     return reconcileTargetsWithChangedFiles(results, options.changedFiles, workDir)
   }
 

src/server/__tests__/sessions.test.ts

@@ -5572,6 +5572,119 @@ describe('Sessions API', () => {
     ])
   })
 
+  it('GET /api/sessions/:id/turn-checkpoints should keep an available empty preview for an unchanged snapshot-backed turn', async () => {
+    const sessionId = '99999999-bbbb-cccc-dddd-000000000005'
+    const workDir = path.join(tmpDir, 'unchanged-snapshot-session')
+    const targetFile = path.join(workDir, 'src', 'unchanged.ts')
+    const userId = crypto.randomUUID()
+    const backupName = 'unchanged-snapshot@v1'
+    const content = 'export const unchanged = true\n'
+
+    await fs.mkdir(path.dirname(targetFile), { recursive: true })
+    await fs.writeFile(targetFile, content, 'utf-8')
+    await writeFileHistoryBackup(sessionId, backupName, content)
+    await writeSessionFile('-tmp-unchanged-snapshot-session', sessionId, [
+      makeSessionMetaEntry(workDir),
+      makeFileHistorySnapshotEntry(userId, {
+        'src/unchanged.ts': {
+          backupFileName: backupName,
+          version: 1,
+          backupTime: '2026-01-01T00:00:00.000Z',
+        },
+      }),
+      {
+        ...makeUserEntry('inspect the project', userId),
+        cwd: workDir,
+        sessionId,
+      },
+      makeAssistantEntry('No files needed changes.', userId),
+    ])
+
+    const res = await fetch(`${baseUrl}/api/sessions/${sessionId}/turn-checkpoints`)
+    expect(res.status).toBe(200)
+    const body = await res.json() as {
+      checkpoints: Array<{
+        target: { targetUserMessageId: string }
+        code: {
+          available: boolean
+          filesChanged: string[]
+          insertions: number
+          deletions: number
+        }
+      }>
+    }
+
+    expect(body.checkpoints).toHaveLength(1)
+    expect(body.checkpoints[0]).toMatchObject({
+      target: { targetUserMessageId: userId },
+      code: {
+        available: true,
+        filesChanged: [],
+        insertions: 0,
+        deletions: 0,
+      },
+    })
+  })
+
+  it('GET /api/sessions/:id/turn-checkpoints should retain transcript changes when the snapshot diff is empty', async () => {
+    const sessionId = '99999999-bbbb-cccc-dddd-000000000006'
+    const workDir = path.join(tmpDir, 'empty-snapshot-transcript-session')
+    const unchangedFile = path.join(workDir, 'src', 'unchanged.ts')
+    const transcriptFile = path.join(workDir, 'test123.md')
+    const userId = crypto.randomUUID()
+    const backupName = 'empty-snapshot-transcript@v1'
+    const content = 'export const unchanged = true\n'
+
+    await fs.mkdir(path.dirname(unchangedFile), { recursive: true })
+    await fs.writeFile(unchangedFile, content, 'utf-8')
+    await writeFileHistoryBackup(sessionId, backupName, content)
+    await writeSessionFile('-tmp-empty-snapshot-transcript-session', sessionId, [
+      makeSessionMetaEntry(workDir),
+      makeFileHistorySnapshotEntry(userId, {
+        'src/unchanged.ts': {
+          backupFileName: backupName,
+          version: 1,
+          backupTime: '2026-01-01T00:00:00.000Z',
+        },
+      }),
+      {
+        ...makeUserEntry('write a short note', userId),
+        cwd: workDir,
+        sessionId,
+      },
+      makeAssistantToolUseEntry([{
+        id: 'Write:empty-snapshot-fallback',
+        name: 'Write',
+        input: {
+          file_path: transcriptFile,
+          content: '# Notes\n',
+        },
+      }], userId),
+      makeAssistantEntry('Note written.', userId),
+    ])
+
+    const res = await fetch(`${baseUrl}/api/sessions/${sessionId}/turn-checkpoints`)
+    expect(res.status).toBe(200)
+    const body = await res.json() as {
+      checkpoints: Array<{
+        code: {
+          available: boolean
+          filesChanged: string[]
+          insertions: number
+          deletions: number
+        }
+      }>
+    }
+
+    expect(body.checkpoints).toHaveLength(1)
+    expect(body.checkpoints[0]!.code).toEqual({
+      available: true,
+      filesChanged: [transcriptFile],
+      insertions: 1,
+      deletions: 0,
+    })
+  })
+
   it('GET /api/sessions/:id/turn-checkpoints/diff should return target-bound checkpoint diffs', async () => {
     const fixture = await createThreeTurnCheckpointFixture(
       '99999999-bbbb-cccc-dddd-ffffffffffff',

src/server/services/sessionRewindService.ts

@@ -955,15 +955,19 @@ export async function listSessionTurnCheckpoints(
     const checkpointPreview = targetSnapshot
       ? await buildTurnCodePreview(sessionId, checkpointBaseDir, targetSnapshot, nextSnapshot)
       : null
-    const preview = checkpointPreview?.available && checkpointPreview.filesChanged.length > 0
-      ? checkpointPreview
-      : buildTranscriptTurnCodePreview(
-          activeMessages,
-          target.targetUserMessageId,
-          checkpointBaseDir,
-        )
-
-    if (!preview.available || preview.filesChanged.length === 0) continue
+    let preview = checkpointPreview
+    if (!preview?.available || preview.filesChanged.length === 0) {
+      const transcriptPreview = buildTranscriptTurnCodePreview(
+        activeMessages,
+        target.targetUserMessageId,
+        checkpointBaseDir,
+      )
+      if (transcriptPreview.available) {
+        preview = transcriptPreview
+      }
+    }
+
+    if (!preview?.available) continue
     checkpoints.push(buildTurnPreview(target, preview, checkpointBaseDir))
   }