fix(core): preserve reasoning_content in rewind, compression, and merge paths (#3579)

packages/cli/src/ui/AppContainer.tsx

@@ -1739,9 +1739,10 @@ export const AppContainer = (props: AppContainerProps) => {
         return;
       }
 
-      // 3. Truncate API history and strip stale thinking blocks
+      // 3. Truncate API history to the target point.
+      // Do NOT strip thought parts — reasoning models (e.g. DeepSeek) require
+      // reasoning_content continuity across all turns in the conversation.
       geminiClient.truncateHistory(apiTruncateIndex);
-      geminiClient.stripThoughtsFromHistory();
 
       // 4. Truncate UI history (keep everything before the target item)
       const truncatedUi = originalHistory.filter((h) => h.id < userItem.id);

packages/core/src/config/config.test.ts

@@ -168,7 +168,6 @@ vi.mock('../core/client.js', () => ({
   GeminiClient: vi.fn().mockImplementation(() => ({
     initialize: vi.fn().mockResolvedValue(undefined),
     isInitialized: vi.fn().mockReturnValue(true),
-    stripThoughtsFromHistory: vi.fn(),
     setTools: vi.fn(),
   })),
 }));
@@ -477,10 +476,6 @@ describe('Server Config (config.ts)', () => {
       await config.refreshAuth(AuthType.USE_VERTEX_AI);
 
       await config.refreshAuth(AuthType.USE_GEMINI);
-
-      expect(
-        config.getGeminiClient().stripThoughtsFromHistory,
-      ).not.toHaveBeenCalledWith();
     });
   });
 
@@ -562,12 +557,7 @@ describe('Server Config (config.ts)', () => {
 
       await config.refreshAuth(AuthType.QWEN_OAUTH);
 
-      const stripSpy = config.getGeminiClient().stripThoughtsFromHistory;
-      vi.mocked(stripSpy).mockClear();
-
       await config.switchModel(AuthType.QWEN_OAUTH, 'coder-model');
-
-      expect(stripSpy).not.toHaveBeenCalled();
     });
   });
 

packages/core/src/core/client.test.ts

@@ -471,7 +471,6 @@ describe('Gemini Client (client.ts)', () => {
       mockChat = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
     });
@@ -512,8 +511,6 @@ describe('Gemini Client (client.ts)', () => {
         getHistory: mockGetHistory,
         addHistory: vi.fn(),
         setHistory: vi.fn(),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       } as unknown as GeminiChat;
     });
 
@@ -534,8 +531,6 @@ describe('Gemini Client (client.ts)', () => {
       const mockOriginalChat: Partial<GeminiChat> = {
         getHistory: vi.fn((_curated?: boolean) => chatHistory),
         setHistory: vi.fn(),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockOriginalChat as GeminiChat;
 
@@ -1227,8 +1222,6 @@ describe('Gemini Client (client.ts)', () => {
       const mockChat = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       } as unknown as GeminiChat;
       client['chat'] = mockChat;
 
@@ -1283,8 +1276,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1340,8 +1331,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1400,7 +1389,6 @@ hello
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1463,7 +1451,6 @@ hello
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1519,7 +1506,6 @@ hello
           { role: 'user', parts: [{ text: 'I prefer terse responses.' }] },
           { role: 'model', parts: [{ text: 'Done' }] },
         ]),
-        stripThoughtsFromHistory: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1583,8 +1569,6 @@ hello
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1623,8 +1607,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1669,8 +1651,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1758,8 +1738,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1816,8 +1794,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -1898,8 +1874,6 @@ Other open files:
             .mockReturnValue([
               { role: 'user', parts: [{ text: 'previous message' }] },
             ]),
-          stripThoughtsFromHistory: vi.fn(),
-          stripThoughtsFromHistoryKeepRecent: vi.fn(),
         };
         client['chat'] = mockChat as GeminiChat;
       });
@@ -2152,8 +2126,6 @@ Other open files:
           addHistory: vi.fn(),
           getHistory: vi.fn().mockReturnValue([]), // Default empty history
           setHistory: vi.fn(),
-          stripThoughtsFromHistory: vi.fn(),
-          stripThoughtsFromHistoryKeepRecent: vi.fn(),
         };
         client['chat'] = mockChat as GeminiChat;
 
@@ -2492,8 +2464,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -2530,8 +2500,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -2571,8 +2539,6 @@ Other open files:
       const mockChat: Partial<GeminiChat> = {
         addHistory: vi.fn(),
         getHistory: vi.fn().mockReturnValue([]),
-        stripThoughtsFromHistory: vi.fn(),
-        stripThoughtsFromHistoryKeepRecent: vi.fn(),
       };
       client['chat'] = mockChat as GeminiChat;
 
@@ -2596,8 +2562,6 @@ Other open files:
           addHistory: vi.fn(),
           getHistory: vi.fn().mockReturnValue([]),
           setHistory: vi.fn(),
-          stripThoughtsFromHistory: vi.fn(),
-          stripThoughtsFromHistoryKeepRecent: vi.fn(),
           stripOrphanedUserEntriesFromHistory: vi.fn(),
         };
         client['chat'] = mockChat as GeminiChat;
@@ -2629,8 +2593,6 @@ Other open files:
           addHistory: vi.fn(),
           getHistory: vi.fn().mockReturnValue([]),
           setHistory: vi.fn(),
-          stripThoughtsFromHistory: vi.fn(),
-          stripThoughtsFromHistoryKeepRecent: vi.fn(),
           stripOrphanedUserEntriesFromHistory: vi.fn(),
         };
         client['chat'] = mockChat as GeminiChat;
@@ -2674,8 +2636,6 @@ Other open files:
         mockChat = {
           addHistory: vi.fn(),
           getHistory: vi.fn().mockReturnValue([]),
-          stripThoughtsFromHistory: vi.fn(),
-          stripThoughtsFromHistoryKeepRecent: vi.fn(),
         };
         client['chat'] = mockChat as GeminiChat;
       });

packages/core/src/core/client.ts

@@ -204,10 +204,6 @@ export class GeminiClient {
     return this.getChat().getHistory(curated);
   }
 
-  stripThoughtsFromHistory() {
-    this.getChat().stripThoughtsFromHistory();
-  }
-
   private stripOrphanedUserEntriesFromHistory() {
     this.getChat().stripOrphanedUserEntriesFromHistory();
   }