feat(FN-4422): restore last active quick chat session on reopen

Restores the latest active quick chat session when the QuickChatFAB is opened, with corresponding test coverage for the restored session behavior.

Fusion-Task-Id: FN-4422

.changeset/fn-4422-quick-chat-restore.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Quick Chat now reliably restores the most recently active non-archived conversation by session ID when reopened, instead of occasionally landing on an older thread that shares the same target.

packages/dashboard/app/components/QuickChatFAB.tsx

@@ -939,6 +939,7 @@ export function QuickChatFAB({
   const modelsInitSettledRef = useRef(false);
   const prevSessionTargetRef = useRef("");
   const hasAppliedInitialSessionRef = useRef(false);
+  const restoredFromExistingSessionRef = useRef(false);
   const selectedAgentIdRef = useRef(selectedAgentId);
   const selectedModelRef = useRef(selectedModel);
   const mentionCursorPosRef = useRef(0);
@@ -1234,21 +1235,35 @@ export function QuickChatFAB({
       return;
     }
 
-    const latestSession = sessions[0];
+    const activeSessions = sessions.filter((session) => session.status !== "archived");
-    if (!latestSession) {
+    const timestamp = (value?: string | null): number => {
-      return;
+      if (!value) return 0;
-    }
+      const parsed = Date.parse(value);
+      return Number.isFinite(parsed) ? parsed : 0;
+    };
+    const latestSession = [...activeSessions].sort((a, b) => {
+      const aLastTouched = Math.max(timestamp(a.lastMessageAt), timestamp(a.updatedAt));
+      const bLastTouched = Math.max(timestamp(b.lastMessageAt), timestamp(b.updatedAt));
+      return bLastTouched - aLastTouched;
+    })[0];
 
-    if (latestSession.modelProvider && latestSession.modelId) {
+    if (latestSession) {
-      setChatMode("model");
+      if (latestSession.modelProvider && latestSession.modelId) {
-      setSelectedModel(`${latestSession.modelProvider}/${latestSession.modelId}`);
+        setChatMode("model");
+        setSelectedModel(`${latestSession.modelProvider}/${latestSession.modelId}`);
+      } else {
+        setChatMode("agent");
+        setSelectedAgentId(latestSession.agentId);
+      }
+
+      restoredFromExistingSessionRef.current = true;
+      void selectSession(latestSession);
     } else {
-      setChatMode("agent");
+      restoredFromExistingSessionRef.current = false;
-      setSelectedAgentId(latestSession.agentId);
     }
 
     hasAppliedInitialSessionRef.current = true;
-  }, [isOpen, sessions, sessionsLoading]);
+  }, [isOpen, selectSession, sessions, sessionsLoading]);
 
   // Initialize/switch quick chat session whenever the selected target changes.
   // NOTE: activeSession and sessionsLoading are in the dependency array to
@@ -1287,6 +1302,12 @@ export function QuickChatFAB({
       && !activeSession
       && !sessionsLoading;
 
+    if (restoredFromExistingSessionRef.current) {
+      restoredFromExistingSessionRef.current = false;
+      prevSessionTargetRef.current = sessionTargetKey;
+      return;
+    }
+
     if (sessionTargetKey === prevSessionTargetRef.current && !shouldRetrySessionInit) {
       return;
     }

packages/dashboard/app/components/__tests__/QuickChatFAB.test.tsx

@@ -164,9 +164,22 @@ describe("QuickChatFAB session-first UX", () => {
     expect(screen.getByTestId("quick-chat-new-model-select")).toBeInTheDocument();
   });
 
-  it("restores the newest agent session target on first open after reload", async () => {
+  it("restores the most recently touched active session by id", async () => {
     mockFetchChatSessions.mockResolvedValueOnce({
-      sessions: [agentTwoSession, modelSession, agentSession],
+      sessions: [
+        {
+          ...modelSession,
+          id: "older-updated",
+          updatedAt: "2026-05-13T10:00:00.000Z",
+          lastMessageAt: "2026-05-13T10:00:00.000Z",
+        },
+        {
+          ...agentTwoSession,
+          id: "newer-last-message",
+          updatedAt: "2026-05-13T09:00:00.000Z",
+          lastMessageAt: "2026-05-13T11:00:00.000Z",
+        },
+      ],
     });
 
     render(<QuickChatFAB addToast={vi.fn()} projectId="proj-1" />);
@@ -174,25 +187,38 @@ describe("QuickChatFAB session-first UX", () => {
 
     await waitFor(() => {
       expect(screen.getByTestId("quick-chat-input")).toHaveAttribute("placeholder", "Message Agent Two");
+      expect(screen.getByTestId("quick-chat-session-dropdown")).toHaveValue("newer-last-message");
     });
-    expect(mockFetchResumeChatSession).toHaveBeenCalledWith({ agentId: "agent-002" }, "proj-1");
+    expect(mockFetchResumeChatSession).not.toHaveBeenCalled();
   });
 
-  it("restores the newest model session target instead of the configured default", async () => {
+  it("skips archived newest sessions and restores the newest active session", async () => {
     mockFetchChatSessions.mockResolvedValueOnce({
-      sessions: [modelSessionAnthropic, modelSession, agentSession],
+      sessions: [
+        {
+          ...modelSessionAnthropic,
+          id: "archived-newest",
+          status: "archived",
+          updatedAt: "2026-05-13T12:00:00.000Z",
+          lastMessageAt: "2026-05-13T12:00:00.000Z",
+        },
+        {
+          ...agentTwoSession,
+          id: "active-latest",
+          updatedAt: "2026-05-13T11:00:00.000Z",
+          lastMessageAt: "2026-05-13T11:00:00.000Z",
+        },
+      ],
     });
 
     render(<QuickChatFAB addToast={vi.fn()} projectId="proj-1" />);
     fireEvent.click(screen.getByTestId("quick-chat-fab"));
 
     await waitFor(() => {
-      expect(screen.getByTestId("quick-chat-model-tag")).toHaveTextContent("Claude 3.7 Sonnet");
+      expect(screen.getByTestId("quick-chat-input")).toHaveAttribute("placeholder", "Message Agent Two");
+      expect(screen.getByTestId("quick-chat-session-dropdown")).toHaveValue("active-latest");
     });
-    expect(mockFetchResumeChatSession).toHaveBeenCalledWith(
+    expect(screen.getByRole("option", { name: /Claude thread/i })).toBeInTheDocument();
-      { agentId: "__fn_agent__", modelProvider: "anthropic", modelId: "claude-3-7-sonnet" },
-      "proj-1",
-    );
   });
 
   it("falls back to the existing default target when there are no prior sessions", async () => {