FN-7275: fix mobile task-detail swipe-back dismissal

Harden mobile navigation history so reopened task detail surfaces remain dismissible after stale back events.

- Reconcile duplicate navigation entries with replaceState while preserving existing history state.
- Treat stale or desynced popstate navIndex values as a top-entry dismiss instead of a no-op.
- Cover close-and-quick-reopen swipe-back races across the hook, task-detail modal, and app navigation tests.
- Add the navigation history tests to the dashboard quality test allowlists and include a patch changeset.

Files changed:
 .changeset/fn-7275-swipe-back-reliability.md       |  7 ++
 .../__tests__/TaskDetail.swipe-back.test.tsx       | 14 +++-
 .../__tests__/navigation-history.test.tsx          | 18 +++--
 .../hooks/__tests__/useNavigationHistory.test.ts   | 43 +++++++++-
 .../dashboard/app/hooks/useNavigationHistory.ts    | 92 ++++++++++++++--------
 packages/dashboard/vitest.config.ts                |  3 +-
 6 files changed, 128 insertions(+), 49 deletions(-)

Fusion-Task-Id: FN-7275

Fusion-Task-Lineage: f01e46c3-e6ad-45ef-a848-e8e2012ea3d1

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-7275-swipe-back-reliability.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Mobile back now reliably dismisses the open task detail, including right after closing and reopening it.
+category: fix
+dev: Hardens useNavigationHistory against close-reopen races and history/stack desync so popstate (and the fusion:native-back event) deterministically dismisses every task-detail surface.

packages/dashboard/app/components/__tests__/TaskDetail.swipe-back.test.tsx

@@ -587,7 +587,7 @@ describe("Task detail mobile swipe-back", () => {
     });
   });
 
-  it("pushes a fresh mobile nav entry after close and reopen from the list", async () => {
+  it("dismisses the reopened list-mobile detail after a close-and-quick-reopen race", async () => {
     const task = makeTask("FN-1", "Repeat Mobile List Detail");
     mockUseTasks.mockImplementation(() => ({
       tasks: [task],
@@ -614,8 +614,13 @@ describe("Task detail mobile swipe-back", () => {
     });
     expect(window.history.pushState).toHaveBeenCalledTimes(1);
 
+    /*
+    FNXC:TaskDetailSwipeBack 2026-06-30-09:31:
+    The list-mobile modal path uses the shared closeDetailTask callback, so the
+    race repro must prove a deferred removeNav self-pop cannot strand the next
+    reopen without a dismissible mobile history entry.
+    */
     fireEvent.click(screen.getByTestId("task-detail-close"));
-    dispatchPopState({ navIndex: 0 });
     await waitFor(() => {
       expect(screen.queryByTestId("task-detail-modal")).toBeNull();
     });
@@ -625,9 +630,10 @@ describe("Task detail mobile swipe-back", () => {
       expect(screen.getByTestId("task-detail-modal")).toBeInTheDocument();
     });
 
-    expect(window.history.pushState).toHaveBeenCalledTimes(2);
+    dispatchPopState({ navIndex: 1 });
+    expect(screen.getByTestId("task-detail-modal")).toBeInTheDocument();
 
-    dispatchPopState({ navIndex: 0 });
+    dispatchPopState({ navIndex: 1 });
     await waitFor(() => {
       expect(screen.queryByTestId("task-detail-modal")).toBeNull();
       expect(screen.getByTestId("list-view")).toBeInTheDocument();

packages/dashboard/app/components/__tests__/navigation-history.test.tsx

@@ -627,7 +627,7 @@ describe("Navigation history integration", () => {
     });
   });
 
-  it("dismisses task detail on mobile popstate after close and reopen", async () => {
+  it("dismisses task detail on mobile popstate after a close-and-quick-reopen race", async () => {
     mockUseViewportMode.mockReturnValue("mobile");
     const task = makeTask("FN-1", "Mobile Swipe Detail");
     mockUseTasks.mockImplementation(() => ({
@@ -647,7 +647,13 @@ describe("Navigation history integration", () => {
 
     await renderMobileAppAndWait();
 
-    // FNXC:Navigation 2026-06-22-00:00: Board card click opens the full main-panel detail; the "Back to board" button reverts to the board, and a subsequent reopen + mobile popstate must also dismiss it (the regression this test guards).
+    /*
+    FNXC:TaskDetailSwipeBack 2026-06-30-09:29:
+    Reproduces the real FN-7275 race: Back-to-board queues a self-pop through
+    history.back(), but the user can reopen the detail before that popstate
+    resolves. The next swipe-back must still dismiss the reopened detail even
+    when history surfaces the stale pre-close navIndex first.
+    */
     fireEvent.click(screen.getByTestId("open-task-FN-1"));
 
     await waitFor(() => {
@@ -655,9 +661,6 @@ describe("Navigation history integration", () => {
     });
 
     fireEvent.click(screen.getByRole("button", { name: "Back to board" }));
-    // removeNav drives history.back(); consume the self-triggered popstate
-    // before reopening so the next popstate represents the user's swipe-back.
-    dispatchPopState({ navIndex: 0 });
 
     await waitFor(() => {
       expect(screen.queryByTestId("task-detail-main-panel-content")).toBeNull();
@@ -670,7 +673,10 @@ describe("Navigation history integration", () => {
       expect(screen.getByTestId("task-detail-main-panel-content")).toBeTruthy();
     });
 
-    dispatchPopState({ navIndex: 0 });
+    dispatchPopState({ navIndex: 1 });
+    expect(screen.getByTestId("task-detail-main-panel-content")).toBeTruthy();
+
+    dispatchPopState({ navIndex: 1 });
 
     await waitFor(() => {
       expect(screen.queryByTestId("task-detail-main-panel-content")).toBeNull();

packages/dashboard/app/hooks/__tests__/useNavigationHistory.test.ts

@@ -187,6 +187,43 @@ describe("useNavigationHistory", () => {
     expect(pushStateSpy).toHaveBeenCalledTimes(2);
   });
 
+  it("dismisses the reopened top entry after a deferred self-pop leaves stale navIndex state", () => {
+    const closeA = vi.fn();
+    const closeB = vi.fn();
+    const { result } = renderHookWithHistory();
+
+    act(() => {
+      result.current.pushNav({ type: "modal", close: closeA });
+      result.current.removeNav(closeA);
+      result.current.pushNav({ type: "modal", close: closeB });
+    });
+
+    // The deferred removeNav pop arrives after the reopen and is consumed.
+    dispatchPopState({ navIndex: 1 });
+    expect(closeA).not.toHaveBeenCalled();
+    expect(closeB).not.toHaveBeenCalled();
+
+    // FNXC:TaskDetailSwipeBack 2026-06-30-09:25:
+    // Mobile swipe-back must still dismiss the reopened surface even when
+    // history retained a stale navIndex from the pre-close entry.
+    dispatchPopState({ navIndex: 1 });
+
+    expect(closeB).toHaveBeenCalledTimes(1);
+  });
+
+  it("falls back to dismissing the top entry when popstate carries a stale navIndex", () => {
+    const close = vi.fn();
+    const { result } = renderHookWithHistory();
+
+    act(() => {
+      result.current.pushNav({ type: "modal", close });
+    });
+
+    dispatchPopState({ navIndex: 3 });
+
+    expect(close).toHaveBeenCalledTimes(1);
+  });
+
   it("keeps stack order consistent after removing the top entry", () => {
     const close1 = vi.fn();
     const close2 = vi.fn();
@@ -297,7 +334,7 @@ describe("useNavigationHistory", () => {
   });
 
   // 9. Duplicate-consecutive-push guard
-  it("skips duplicate consecutive pushes with the same callback", () => {
+  it("reconciles duplicate consecutive pushes with the same callback without adding history", () => {
     const close = vi.fn();
     const { result } = renderHookWithHistory();
 
@@ -307,12 +344,12 @@ describe("useNavigationHistory", () => {
 
     expect(pushStateSpy).toHaveBeenCalledTimes(1);
 
-    // Push the same entry again — should be skipped
     act(() => {
       result.current.pushNav({ type: "modal", close });
     });
 
-    expect(pushStateSpy).toHaveBeenCalledTimes(1); // still only 1 call
+    expect(pushStateSpy).toHaveBeenCalledTimes(1);
+    expect(replaceStateSpy).toHaveBeenCalledWith(expect.objectContaining({ navIndex: 1 }), "");
   });
 
   // 10. Handles rapid popstate (iOS fast swipe) — pops multiple entries

packages/dashboard/app/hooks/useNavigationHistory.ts

@@ -71,6 +71,10 @@ export function useNavigationHistoryContext(): UseNavigationHistoryResult {
  * When `enabled` is false, all operations are no-ops and no `popstate`
  * listener is registered.
  */
+function getEntryCallback(entry: NavEntry): () => void {
+  return entry.type === "modal" ? entry.close : entry.revert;
+}
+
 export function useNavigationHistory(
   options: UseNavigationHistoryOptions,
 ): UseNavigationHistoryResult {
@@ -95,6 +99,30 @@ export function useNavigationHistory(
   const enabledRef = useRef(enabled);
   enabledRef.current = enabled;
 
+  const readExistingState = useCallback(() => {
+    if (typeof window === "undefined") return {};
+    return window.history.state && typeof window.history.state === "object"
+      ? window.history.state
+      : {};
+  }, []);
+
+  const writeHistoryState = useCallback(
+    (mode: "push" | "replace", navIndex: number) => {
+      const nextState = {
+        ...readExistingState(),
+        navIndex,
+      };
+
+      if (mode === "push") {
+        window.history.pushState(nextState, "");
+        return;
+      }
+
+      window.history.replaceState(nextState, "");
+    },
+    [readExistingState],
+  );
+
   const pushNav = useCallback(
     (entry: NavEntry) => {
       if (!enabledRef.current) return;
@@ -102,26 +130,20 @@ export function useNavigationHistory(
       // Prevent re-push during pop handling
       if (isPoppingRef.current) return;
 
-      // Guard against duplicate consecutive pushes (rapid taps)
+      // Guard against duplicate consecutive pushes (rapid taps). If a stale
+      // top entry still uses the same callback, reconcile it in place instead
+      // of silently dropping the reopen and leaving history/stack out of sync.
       const top = stackRef.current[stackRef.current.length - 1];
-      if (top) {
+      if (top && getEntryCallback(top) === getEntryCallback(entry)) {
-        const topCallback = top.type === "modal" ? top.close : top.revert;
+        stackRef.current[stackRef.current.length - 1] = entry;
-        const newCallback = entry.type === "modal" ? entry.close : entry.revert;
+        writeHistoryState("replace", stackRef.current.length);
-        if (topCallback === newCallback) return;
+        return;
       }
 
       stackRef.current.push(entry);
-
+      writeHistoryState("push", stackRef.current.length);
-      // Preserve existing history.state properties (e.g. from useDeepLink)
-      // while adding our navIndex.
-      const navIndex = stackRef.current.length;
-      const existingState =
-        typeof window !== "undefined" && window.history.state
-          ? window.history.state
-          : {};
-      window.history.pushState({ ...existingState, navIndex }, "");
     },
-    [], // stable — reads from refs
+    [writeHistoryState],
   );
 
   const replaceCurrent = useCallback(
@@ -130,16 +152,9 @@ export function useNavigationHistory(
       if (stackRef.current.length === 0) return;
 
       stackRef.current[stackRef.current.length - 1] = entry;
-
+      writeHistoryState("replace", stackRef.current.length);
-      // Preserve existing history.state properties while updating navIndex
-      const navIndex = stackRef.current.length;
-      const existingState =
-        typeof window !== "undefined" && window.history.state
-          ? window.history.state
-          : {};
-      window.history.replaceState({ ...existingState, navIndex }, "");
     },
-    [], // stable — reads from refs
+    [writeHistoryState],
   );
 
   const removeNav = useCallback(
@@ -148,8 +163,7 @@ export function useNavigationHistory(
 
       for (let i = stackRef.current.length - 1; i >= 0; i -= 1) {
         const entry = stackRef.current[i];
-        const callback = entry.type === "modal" ? entry.close : entry.revert;
+        if (getEntryCallback(entry) !== closeOrRevert) continue;
-        if (callback !== closeOrRevert) continue;
 
         stackRef.current.splice(i, 1);
         selfPopRef.current = true;
@@ -198,13 +212,25 @@ export function useNavigationHistory(
         return;
       }
 
-      const targetIndex = event.state?.navIndex ?? 0;
+      const targetIndex = typeof event.state?.navIndex === "number" ? event.state.navIndex : null;
       const currentLength = stackRef.current.length;
 
-      if (targetIndex >= currentLength) return;
+      if (currentLength === 0) return;
 
-      // Calculate how many entries were popped
+      const staleOrDesyncedIndex =
-      const poppedCount = currentLength - targetIndex;
+        targetIndex === null ||
+        targetIndex < 0 ||
+        targetIndex >= currentLength;
+
+      /*
+      FNXC:TaskDetailSwipeBack 2026-06-30-09:40:
+      Mobile swipe-back must deterministically dismiss the top Fusion surface
+      even when browser history carries a stale navIndex from a close→reopen
+      race, remount, or interleaved non-Fusion pushState. Falling back to one
+      top-entry pop keeps the live stack authoritative instead of silently
+      no-oping on `targetIndex >= currentLength`.
+      */
+      const poppedCount = staleOrDesyncedIndex ? 1 : currentLength - targetIndex;
 
       if (poppedCount <= 0) return;
 
@@ -215,11 +241,7 @@ export function useNavigationHistory(
         for (let i = 0; i < poppedCount; i++) {
           const entry = stackRef.current.pop();
           if (entry) {
-            if (entry.type === "modal") {
+            getEntryCallback(entry)();
-              entry.close();
-            } else {
-              entry.revert();
-            }
           }
         }
       } finally {

packages/dashboard/vitest.config.ts

@@ -100,7 +100,7 @@ const qualityAppFoundationUiTests = [
 const qualityAppHooksAndUtilsTests = [
   // Hooks and utilities are fast, user-visible state/formatting behavior.
   "app/context/**/*.test.tsx",
-  "app/hooks/__tests__/{useAgents,useAgentLogs,useAgentLogs.resume-instrumentation,useAppSettings,useAuthOnboarding,useConfirm,useCurrentProject,useNodes,useNodes.resume-instrumentation,useNodeSettingsSync,useProjects,useProjects.resume-instrumentation,useMeshState.resume-instrumentation,useManagedDockerNodes.resume-instrumentation,usePrChecksStream.resume-instrumentation,useDevServerLogs.resume-instrumentation,useResearch.resume-instrumentation,useBackgroundSessions.resume-instrumentation,useQuickChat,useTasks,useTasks.resume-instrumentation,useChatRooms,useTerminalSessions,useTheme,useToast,useUsageData,useViewportMode,useViewState,useMergeAdvanceNotice}.test.{ts,tsx}",
+  "app/hooks/__tests__/{useAgents,useAgentLogs,useAgentLogs.resume-instrumentation,useAppSettings,useAuthOnboarding,useConfirm,useCurrentProject,useNavigationHistory,useNodes,useNodes.resume-instrumentation,useNodeSettingsSync,useProjects,useProjects.resume-instrumentation,useMeshState.resume-instrumentation,useManagedDockerNodes.resume-instrumentation,usePrChecksStream.resume-instrumentation,useDevServerLogs.resume-instrumentation,useResearch.resume-instrumentation,useBackgroundSessions.resume-instrumentation,useQuickChat,useTasks,useTasks.resume-instrumentation,useChatRooms,useTerminalSessions,useTheme,useToast,useUsageData,useViewportMode,useViewState,useMergeAdvanceNotice}.test.{ts,tsx}",
   "app/utils/**/*.test.{ts,tsx}",
 ];
 
@@ -149,6 +149,7 @@ const qualityAppComponentTests = [
   "MemoryView",
   "MergeAdvanceNotice",
   "MessageComposer",
+  "navigation-history",
   "MessageComposer.autosize",
   "MobileNavBar",
   "NewTaskModal",