fix(chat): reprise robuste au retour d'un layout non conversationnel (composer verrouillé selon l'état réel, replay complet du scrollback, plus de fausse terminaison 'no reply') (#190)

frontend/src/features/agents/CustomAgentChatView.test.tsx

@@ -59,6 +59,14 @@ function addPluginCommand(
   });
 }
 
+function deferred<T>() {
+  let resolve!: (value: T | PromiseLike<T>) => void;
+  const promise = new Promise<T>((res) => {
+    resolve = res;
+  });
+  return { promise, resolve };
+}
+
 describe("CustomAgentChatView", () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -174,8 +182,136 @@ describe("CustomAgentChatView", () => {
     expect(await screen.findByText("Background tool")).toBeTruthy();
     expect(screen.getByText("Completed away")).toBeTruthy();
     expect(
-      screen.getByText("Reprise effectuée: 2 événements rattrapés pendant l'absence."),
-    ).toBeTruthy();
+      screen.queryByText(/Reprise effectuée:/),
+    ).toBeNull();
+  });
+
+  it("keeps the composer locked on layout return until reattach replay settles (#190)", async () => {
+    let scrollback: ReplyChunk[] = [
+      { kind: "userPrompt" as const, text: "Initial prompt" },
+      { kind: "final" as const, content: "Initial reply" },
+    ];
+    const secondReattach = deferred<{ sessionId: string; scrollback: ReplyChunk[] }>();
+    const agent = {
+      launchAgentChat: vi.fn(),
+      reattachAgentChat: vi
+        .fn()
+        .mockImplementationOnce(async (sessionId: string) => ({
+          sessionId,
+          scrollback,
+        }))
+        .mockImplementationOnce(() => secondReattach.promise),
+      detachAgentChat: vi.fn(async () => {}),
+      sendAgentChat: vi.fn(async () => {}),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+    const props = {
+      projectId: "project-1",
+      agentId: "agent-1",
+      agentName: "Worker",
+      profile,
+      cwd: "/repo",
+      nodeId: "node-1",
+      sessionId: "chat-session-1",
+      conversationId: "conversation-1",
+      onSessionId: vi.fn(),
+      onConversationId: vi.fn(),
+    };
+
+    const first = render(
+      <DIProvider
+        gateways={{
+          agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView {...props} />
+      </DIProvider>,
+    );
+
+    expect(await screen.findByText("Initial reply")).toBeTruthy();
+    first.unmount();
+    await waitFor(() => expect(agent.detachAgentChat).toHaveBeenCalledWith("chat-session-1"));
+
+    scrollback = [
+      { kind: "userPrompt" as const, text: "Initial prompt" },
+      { kind: "final" as const, content: "Initial reply" },
+      { kind: "userPrompt" as const, text: "Question during graph view" },
+      { kind: "textDelta" as const, text: "Partial answer while away" },
+    ];
+
+    render(
+      <DIProvider
+        gateways={{
+          agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView {...props} />
+      </DIProvider>,
+    );
+
+    expect(screen.getByText("Initial reply")).toBeTruthy();
+    expect(screen.getByRole("button", { name: "Envoyer" }).hasAttribute("disabled")).toBe(true);
+    expect(screen.getByLabelText(/message CLI custom/).hasAttribute("disabled")).toBe(true);
+
+    act(() => {
+      secondReattach.resolve({ sessionId: "chat-session-1", scrollback });
+    });
+
+    expect(await screen.findByText("Question during graph view")).toBeTruthy();
+    expect(screen.getByText("Partial answer while away")).toBeTruthy();
+    expect(screen.queryByText(/Reprise effectuée:/)).toBeNull();
+    expect(screen.getByRole("button", { name: "Stop" })).toBeTruthy();
+    expect(screen.getByLabelText(/message CLI custom/).hasAttribute("disabled")).toBe(true);
+  });
+
+  it("drops a stale no-response chunk when replay contains a later real answer (#190)", async () => {
+    const agent = {
+      launchAgentChat: vi.fn(),
+      reattachAgentChat: vi.fn(async (sessionId: string) => ({
+        sessionId,
+        scrollback: [
+          { kind: "userPrompt" as const, text: "resume the turn" },
+          {
+            kind: "error" as const,
+            message: "Le modèle n'a renvoyé aucune réponse.",
+          },
+          { kind: "textDelta" as const, text: "Real answer " },
+          { kind: "final" as const, content: "Real answer completed" },
+        ],
+      })),
+      sendAgentChat: vi.fn(async () => {}),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+
+    render(
+      <DIProvider
+        gateways={{
+          agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    expect(await screen.findByText("Real answer completed")).toBeTruthy();
+    expect(screen.getByText("Real answer")).toBeTruthy();
+    expect(screen.queryByText("Le modèle n'a renvoyé aucune réponse.")).toBeNull();
   });
 
   it("stops the live agent with cascade feedback and releases the structured session", async () => {