Keep desktop replies stable across turns and fix OAuth callback routing

The desktop chat store was dropping the previous assistant draft when a new user turn began because streaming text was cleared before it was flushed into message history. At the same time, the desktop OAuth flow was using an unregistered /api/haha-oauth/callback redirect URI, which caused provider authorization failures. This change flushes visible assistant drafts before starting a new turn, restores the OAuth redirect to the registered localhost callback, and adds a root callback handler while keeping the legacy API callback path compatible.

Constraint: The OAuth provider only accepts the registered localhost /callback redirect URI
Rejected: Keep the desktop-specific /api/haha-oauth/callback path | provider rejects unsupported redirect URIs
Rejected: Rely on message_complete to persist visible assistant text | next user turn can begin before that event arrives
Confidence: high
Scope-risk: moderate
Directive: Any UI-visible assistant draft must be flushed into messages before a new user turn resets streaming state
Tested: bun test src/server/__tests__/haha-oauth-service.test.ts src/server/__tests__/haha-oauth-api.test.ts src/server/__tests__/conversation-service.test.ts
Tested: cd desktop && bun run test src/stores/chatStore.test.ts
Tested: cd desktop && bun run lint
Not-tested: Manual end-to-end desktop OAuth login after reinstall

desktop/src/stores/chatStore.test.ts

@@ -287,6 +287,44 @@ describe('chatStore history mapping', () => {
     })
   })
 
+  it('flushes the previous assistant draft before starting a new user turn', () => {
+    useChatStore.setState({
+      sessions: {
+        [TEST_SESSION_ID]: {
+          messages: [],
+          chatState: 'streaming',
+          connectionState: 'connected',
+          streamingText: '上一次分析结果 **还在流式区域**',
+          streamingToolInput: '',
+          activeToolUseId: null,
+          activeToolName: null,
+          activeThinkingId: null,
+          pendingPermission: null,
+          tokenUsage: { input_tokens: 0, output_tokens: 0 },
+          elapsedSeconds: 0,
+          statusVerb: '',
+          slashCommands: [],
+          agentTaskNotifications: {},
+          elapsedTimer: null,
+        },
+      },
+    })
+
+    useChatStore.getState().sendMessage(TEST_SESSION_ID, '你是什么模型？')
+
+    expect(useChatStore.getState().sessions[TEST_SESSION_ID]?.messages).toMatchObject([
+      {
+        type: 'assistant_text',
+        content: '上一次分析结果 **还在流式区域**',
+      },
+      {
+        type: 'user_text',
+        content: '你是什么模型？',
+      },
+    ])
+    expect(useChatStore.getState().sessions[TEST_SESSION_ID]?.streamingText).toBe('')
+  })
+
   it('routes member-session messages through team mailbox delivery instead of websocket', async () => {
     const memberSessionId = 'team-member:security-reviewer@test-team'
     getMemberBySessionIdMock.mockReturnValue({

desktop/src/stores/chatStore.ts

@@ -180,8 +180,25 @@ export const useChatStore = create<ChatStore>((set, get) => ({
 
     set((s) => {
       const session = s.sessions[sessionId] ?? createDefaultSessionState()
+      if (flushTimer) {
+        clearTimeout(flushTimer)
+        flushTimer = null
+      }
+      const bufferedDelta = pendingDelta
+      pendingDelta = ''
+      const pendingAssistantText = `${session.streamingText}${bufferedDelta}`.trim()
 
-      const newMessages = [...session.messages]
+      const newMessages = pendingAssistantText
+        ? [
+            ...session.messages,
+            {
+              id: nextId(),
+              type: 'assistant_text' as const,
+              content: pendingAssistantText,
+              timestamp: Date.now(),
+            },
+          ]
+        : [...session.messages]
       if (!isMemberSession && allTasksDone) {
         newMessages.push({
           id: nextId(),

src/server/__tests__/haha-oauth-api.test.ts

@@ -55,7 +55,7 @@ describe('POST /api/haha-oauth/start', () => {
     const data = (await res.json()) as { authorizeUrl: string; state: string }
     expect(data.authorizeUrl).toContain('code_challenge_method=S256')
     expect(data.authorizeUrl).toContain(
-      encodeURIComponent('http://localhost:54321/api/haha-oauth/callback'),
+      encodeURIComponent('http://localhost:54321/callback'),
     )
     expect(data.state).toMatch(/^[A-Za-z0-9_-]+$/)
   })

src/server/__tests__/haha-oauth-service.test.ts

@@ -82,7 +82,7 @@ describe('HahaOAuthService — session management', () => {
     expect(session.authorizeUrl).toContain(`state=${encodeURIComponent(session.state)}`)
     expect(session.authorizeUrl).toContain('redirect_uri=')
     expect(session.authorizeUrl).toContain(encodeURIComponent(
-      'http://localhost:54321/api/haha-oauth/callback',
+      'http://localhost:54321/callback',
     ))
   })
 

src/server/api/haha-oauth.ts

@@ -2,7 +2,8 @@
  * Haha OAuth REST API
  *
  * POST   /api/haha-oauth/start    — 生成 PKCE+state,返回 authorize URL
- * GET    /api/haha-oauth/callback — 用户浏览器 redirect 到此,完成 token 交换
+ * GET    /callback                — 用户浏览器 redirect 到此,完成 token 交换
+ * GET    /api/haha-oauth/callback — 兼容旧路径
  * GET    /api/haha-oauth          — 查询当前登录状态(不回传 token 本体)
  * GET    /api/haha-oauth/status   — 同上(legacy path)
  * DELETE /api/haha-oauth          — 登出,删除 token 文件
@@ -52,24 +53,7 @@ export async function handleHahaOAuthApi(
     }
 
     if (action === 'callback' && req.method === 'GET') {
-      const code = url.searchParams.get('code')
-      const state = url.searchParams.get('state')
-      const error = url.searchParams.get('error')
-
-      if (error) {
-        return html(renderCallbackPage(false, `OAuth provider returned: ${error}`))
-      }
-      if (!code || !state) {
-        return html(renderCallbackPage(false, 'Missing code or state parameter'))
-      }
-
-      try {
-        await hahaOAuthService.completeSession(code, state)
-        return html(renderCallbackPage(true, null))
-      } catch (err) {
-        const msg = err instanceof Error ? err.message : String(err)
-        return html(renderCallbackPage(false, msg))
-      }
+      return handleHahaOAuthCallback(url)
     }
 
     if ((action === undefined || action === 'status') && req.method === 'GET') {
@@ -96,6 +80,27 @@ export async function handleHahaOAuthApi(
   }
 }
 
+export async function handleHahaOAuthCallback(url: URL): Promise<Response> {
+  const code = url.searchParams.get('code')
+  const state = url.searchParams.get('state')
+  const error = url.searchParams.get('error')
+
+  if (error) {
+    return html(renderCallbackPage(false, `OAuth provider returned: ${error}`))
+  }
+  if (!code || !state) {
+    return html(renderCallbackPage(false, 'Missing code or state parameter'))
+  }
+
+  try {
+    await hahaOAuthService.completeSession(code, state)
+    return html(renderCallbackPage(true, null))
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : String(err)
+    return html(renderCallbackPage(false, msg))
+  }
+}
+
 function renderCallbackPage(success: boolean, errorMsg: string | null): string {
   if (success) {
     return `<!doctype html>

src/server/index.ts

@@ -13,6 +13,7 @@ import { teamWatcher } from './services/teamWatcher.js'
 import { cronScheduler } from './services/cronScheduler.js'
 import { handleProxyRequest } from './proxy/handler.js'
 import { ProviderService } from './services/providerService.js'
+import { handleHahaOAuthCallback } from './api/haha-oauth.js'
 
 function readArgValue(flag: string): string | undefined {
   const args = process.argv.slice(2)
@@ -128,6 +129,10 @@ export function startServer(port = PORT, host = HOST) {
         return new Response('WebSocket upgrade failed', { status: 400 })
       }
 
+      if (url.pathname === '/callback') {
+        return handleHahaOAuthCallback(url)
+      }
+
       // REST API
       if (url.pathname.startsWith('/api/')) {
         // Enforce authentication when required

src/server/services/hahaOAuthService.ts

@@ -53,6 +53,7 @@ type FetchProfileFn = (
 ) => Promise<{ subscriptionType: SubscriptionType | null }>
 
 const SESSION_TTL_MS = 5 * 60 * 1000
+const OAUTH_CALLBACK_PATH = '/callback'
 
 export class HahaOAuthService {
   private sessions = new Map<string, OAuthSession>()
@@ -108,14 +109,13 @@ export class HahaOAuthService {
     const codeChallenge = generateCodeChallenge(codeVerifier)
     const state = generateState()
 
-    const baseUrl = buildAuthUrl({
+    const authorizeUrl = buildAuthUrl({
       codeChallenge,
       state,
       port: serverPort,
       isManual: false,
       loginWithClaudeAi: true,
     })
-    const authorizeUrl = this.rewriteCallbackPath(baseUrl, serverPort)
 
     const session: OAuthSession = {
       state,
@@ -128,15 +128,6 @@ export class HahaOAuthService {
     return session
   }
 
-  private rewriteCallbackPath(url: string, port: number): string {
-    const u = new URL(url)
-    u.searchParams.set(
-      'redirect_uri',
-      `http://localhost:${port}/api/haha-oauth/callback`,
-    )
-    return u.toString()
-  }
-
   getSession(state: string): OAuthSession | null {
     const s = this.sessions.get(state)
     if (!s) return null
@@ -197,7 +188,7 @@ export class HahaOAuthService {
     const requestBody = {
       grant_type: 'authorization_code',
       code,
-      redirect_uri: `http://localhost:${port}/api/haha-oauth/callback`,
+      redirect_uri: `http://localhost:${port}${OAUTH_CALLBACK_PATH}`,
       client_id: getOauthConfig().CLIENT_ID,
       code_verifier: verifier,
       state,