fix(webui): hydrate reasoning and tool traces from history

Live reasoning/tool frames were rendering correctly, but refreshing WebUI replayed only role/content/media from `/api/sessions/:key/messages`. Assistant `reasoning_content` / `thinking_blocks` and `tool_calls` were already persisted by the backend and returned by the history endpoint, but useSessionHistory discarded them. Hydrate persisted assistant reasoning into `UIMessage.reasoning` and reconstruct assistant tool calls as `kind: "trace"` rows so the replayed thread keeps the same Thinking bubble and Used tools block as the live stream. Tool result rows remain hidden from the conversation view to avoid replaying raw tool output as chat text. Adds regression coverage for both persisted reasoning and historical tool call trace hydration. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-05-13 07:33:52 +00:00
parent 0033a8a185
commit 278affc25e
3 changed files with 149 additions and 5 deletions
@@ -170,6 +170,92 @@ describe("useSessions", () => {
    ]);
  });

+  it("hydrates persisted assistant reasoning into the replayed message", async () => {
+    vi.mocked(api.fetchSessionMessages).mockResolvedValue({
+      key: "websocket:chat-reasoning",
+      created_at: "2026-04-20T10:00:00Z",
+      updated_at: "2026-04-20T10:05:00Z",
+      messages: [
+        {
+          role: "assistant",
+          content: "final answer",
+          timestamp: "2026-04-20T10:00:01Z",
+          reasoning_content: "hidden but persisted reasoning",
+        },
+      ],
+    });
+
+    const { result } = renderHook(() => useSessionHistory("websocket:chat-reasoning"), {
+      wrapper: wrap(fakeClient()),
+    });
+
+    await waitFor(() => expect(result.current.loading).toBe(false));
+
+    expect(result.current.messages).toHaveLength(1);
+    expect(result.current.messages[0].role).toBe("assistant");
+    expect(result.current.messages[0].content).toBe("final answer");
+    expect(result.current.messages[0].reasoning).toBe("hidden but persisted reasoning");
+    expect(result.current.messages[0].reasoningStreaming).toBe(false);
+  });
+
+  it("hydrates historical assistant tool calls into a replay trace row", async () => {
+    vi.mocked(api.fetchSessionMessages).mockResolvedValue({
+      key: "websocket:chat-tools",
+      created_at: "2026-04-20T10:00:00Z",
+      updated_at: "2026-04-20T10:05:00Z",
+      messages: [
+        {
+          role: "user",
+          content: "research this",
+          timestamp: "2026-04-20T10:00:00Z",
+        },
+        {
+          role: "assistant",
+          content: "",
+          timestamp: "2026-04-20T10:00:01Z",
+          tool_calls: [
+            {
+              id: "call-1",
+              type: "function",
+              function: { name: "web_search", arguments: "{\"query\":\"agents\"}" },
+            },
+            {
+              id: "call-2",
+              type: "function",
+              function: { name: "web_fetch", arguments: "{\"url\":\"https://example.com\"}" },
+            },
+          ],
+        },
+        {
+          role: "tool",
+          content: "tool output that should not render directly",
+          timestamp: "2026-04-20T10:00:02Z",
+          tool_call_id: "call-1",
+        },
+        {
+          role: "assistant",
+          content: "summary",
+          timestamp: "2026-04-20T10:00:03Z",
+        },
+      ],
+    });
+
+    const { result } = renderHook(() => useSessionHistory("websocket:chat-tools"), {
+      wrapper: wrap(fakeClient()),
+    });
+
+    await waitFor(() => expect(result.current.loading).toBe(false));
+
+    expect(result.current.messages.map((m) => m.role)).toEqual(["user", "tool", "assistant"]);
+    const trace = result.current.messages[1];
+    expect(trace.kind).toBe("trace");
+    expect(trace.traces).toEqual([
+      "web_search({\"query\":\"agents\"})",
+      "web_fetch({\"url\":\"https://example.com\"})",
+    ]);
+    expect(result.current.messages[2].content).toBe("summary");
+  });
+
  it("flags history with trailing assistant tool calls as still pending", async () => {
    vi.mocked(api.fetchSessionMessages).mockResolvedValue({
      key: "websocket:chat-pending",