fix(chat): 重新生成前撤销旧消息

src/components/chat/hooks/useAgentChatSession.test.tsx

@@ -521,4 +521,33 @@ describe("useAgentChatSession", () => {
       expect.anything(),
     );
   });
+
+  it("asks the backend to undo the previous user turn before regenerating", async () => {
+    listChatSessions.mockResolvedValue([]);
+
+    const { result } = renderHook(() =>
+      useAgentChatSession({
+        projectId: "project-1",
+        onToolCall: jest.fn(),
+      }),
+    );
+
+    await waitFor(() => expect(result.current.isHydrating).toBe(false));
+
+    await act(async () => {
+      await result.current.sendPrompt("重新分析压力异常");
+    });
+
+    await act(async () => {
+      await result.current.regenerate();
+    });
+
+    expect(streamAgentChat).toHaveBeenNthCalledWith(
+      2,
+      expect.objectContaining({
+        message: "重新分析压力异常",
+        regenerateFromMessageIndex: 0,
+      }),
+    );
+  });
 });

src/components/chat/hooks/useAgentChatSession.ts

@@ -56,6 +56,7 @@ type UseAgentChatSessionOptions = {
 type PromptRunOptions = {
   prompt: string;
   sessionIdOverride?: string;
+  regenerateFromMessageIndex?: number;
   preparedMessages?: Message[];
   userMessage?: Message;
   assistantMessage?: Message;
@@ -609,6 +610,7 @@ export const useAgentChatSession = ({
     async ({
       prompt: rawPrompt,
       sessionIdOverride,
+      regenerateFromMessageIndex,
       preparedMessages,
       userMessage,
       assistantMessage,
@@ -644,6 +646,7 @@ export const useAgentChatSession = ({
           sessionId: sessionIdOverride ?? sessionIdRef.current,
           model: getModel?.(),
           approvalMode: getApprovalMode?.(),
+          regenerateFromMessageIndex,
           signal: controller.signal,
           onEvent: (event) =>
             applyStreamEvent(event, {
@@ -991,6 +994,7 @@ export const useAgentChatSession = ({
       setMessages(nextMessages);
       await runPrompt({
         prompt: lastUserContent,
+        regenerateFromMessageIndex: lastUserIndex,
         preparedMessages: [
           ...nextMessages,
           nextUserMessage,