feat: optimize chat think

packages/client/runtime/tests/notifier.spec.ts

@@ -1,13 +1,17 @@
 /**
- * Notifier: microtask batching, rebuild-before-notify ordering, no-listener
- * laziness, synchronous notifyNow, and unsubscribe.
+ * Notifier: microtask/frame batching, rebuild-before-notify ordering,
+ * no-listener laziness, synchronous notifyNow, and unsubscribe.
  */
 
-import { describe, expect, it } from 'vitest'
+import { afterEach, describe, expect, it, vi } from 'vitest'
 import { Notifier } from '../src/client/sessions/notifier.ts'
 
 const microtask = (): Promise<void> => new Promise((resolve) => { queueMicrotask(resolve) })
 
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
 describe('Notifier', () => {
   it('collapses N markDirty calls into one flush, rebuilding before notifying', async () => {
     const order: string[] = []
@@ -60,6 +64,57 @@ describe('Notifier', () => {
     expect(rebuilds).toBe(1)
   })
 
+  it('collapses frame-dirty changes into one cumulative frame publication', () => {
+    const frames: FrameRequestCallback[] = []
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => {
+      frames.push(callback)
+      return frames.length
+    })
+    const order: string[] = []
+    const notifier = new Notifier(() => order.push('rebuild'))
+    notifier.subscribe(() => order.push('notify'))
+
+    notifier.markFrameDirty()
+    notifier.markFrameDirty()
+    notifier.markFrameDirty()
+
+    expect(order).toEqual([])
+    expect(frames).toHaveLength(1)
+    frames.shift()!(0)
+    expect(order).toEqual(['rebuild', 'notify'])
+  })
+
+  it('lets a structural microtask publication supersede a pending frame', async () => {
+    const frames: FrameRequestCallback[] = []
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => {
+      frames.push(callback)
+      return frames.length
+    })
+    let notifications = 0
+    const notifier = new Notifier(() => undefined)
+    notifier.subscribe(() => { notifications++ })
+
+    notifier.markFrameDirty()
+    notifier.markDirty()
+    await microtask()
+    expect(notifications).toBe(1)
+
+    frames.shift()!(0)
+    expect(notifications).toBe(1)
+  })
+
+  it('falls back to microtask batching when animation frames are unavailable', async () => {
+    let notifications = 0
+    const notifier = new Notifier(() => undefined)
+    notifier.subscribe(() => { notifications++ })
+
+    notifier.markFrameDirty()
+    notifier.markFrameDirty()
+    expect(notifications).toBe(0)
+    await microtask()
+    expect(notifications).toBe(1)
+  })
+
   it('unsubscribed listeners stop receiving notifications', async () => {
     let calls = 0
     const notifier = new Notifier(() => undefined)

packages/client/runtime/tests/session.spec.ts

@@ -6,7 +6,7 @@
  * enough.
  */
 
-import { describe, expect, it, vi } from 'vitest'
+import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
 import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
@@ -20,6 +20,10 @@ const at = (seq: number, e: Record<string, unknown>): SessionEvent =>
 const SID = 'fk-s1' as SessionId
 const PARENT = 'fk-parent' as SessionId
 
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
 function makeSession(api = new FakeApiClient()): { api: FakeApiClient; session: Session } {
   return { api, session: new Session(SID, api) }
 }
@@ -163,6 +167,40 @@ describe('live event path', () => {
     expect((last as { interrupted?: true }).interrupted).toBeUndefined()
   })
 
+  it('publishes cumulative chunks once per frame and lets finalization supersede the pending frame', async () => {
+    const frames: FrameRequestCallback[] = []
+    vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) => {
+      frames.push(callback)
+      return frames.length
+    })
+    const { session } = await opened()
+    const published: Array<string | null> = []
+    session.subscribe(() => {
+      const block = session.getSnapshot().partial?.blocks[0]
+      published.push(block?.kind === 'text' ? block.text : null)
+    })
+    const feed = (event: SessionEvent) => {
+      session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event })
+    }
+
+    feed(ev.chunkStart(6, 1))
+    feed(ev.chunkText(7, 1, '累'))
+    feed(ev.chunkText(8, 1, '计'))
+    expect(published).toEqual([])
+    expect(frames).toHaveLength(1)
+
+    frames.shift()!(0)
+    expect(published).toEqual(['累计'])
+
+    feed(ev.chunkText(9, 1, '完成'))
+    feed(ev.assistant(10, 1, '累计完成'))
+    await Promise.resolve()
+    expect(published).toEqual(['累计', null])
+
+    frames.shift()!(0)
+    expect(published).toEqual(['累计', null])
+  })
+
   it('retracts the failed step partial on retry and keeps a replayable notice before the recovered response', async () => {
     const { session } = await opened()
     const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }