fix(desktop): input during window teardown no longer throws in the main process

apps/desktop/src/window/DesktopWindow.test.ts

@@ -697,6 +697,55 @@ describe("DesktopWindow", () => {
     }),
   );
 
+  it.effect("ignores input that arrives after the window is destroyed", () =>
+    Effect.gen(function* () {
+      const fakeWindow = makeFakeBrowserWindow();
+      const createCount = yield* Ref.make(0);
+      const mainWindow = yield* Ref.make<Option.Option<Electron.BrowserWindow>>(Option.none());
+      const layer = layerTest({
+        window: fakeWindow.window,
+        createCount,
+        mainWindow,
+      });
+
+      yield* Effect.gen(function* () {
+        const desktopWindow = yield* DesktopWindow.DesktopWindow;
+        yield* desktopWindow.handleBackendReady(new URL("http://127.0.0.1:3773"));
+
+        const beforeInput = fakeWindow.webContentsListeners.get("before-input-event");
+        const inputEvent = fakeWindow.webContentsListeners.get("input-event");
+        if (!beforeInput || !inputEvent) {
+          return yield* Effect.die("input listeners were not registered");
+        }
+
+        // Electron throws on any member access of a destroyed BrowserWindow.
+        fakeWindow.isDestroyed.mockReturnValue(true);
+        Object.defineProperty(fakeWindow.window, "webContents", {
+          get: () => {
+            throw new TypeError("Object has been destroyed");
+          },
+        });
+
+        // A held Cmd+Q quits from the grace timer, so the trailing Q keyUp lands here.
+        assert.doesNotThrow(() =>
+          beforeInput(
+            { preventDefault: () => {} },
+            {
+              type: "keyUp",
+              isAutoRepeat: false,
+              key: "q",
+              meta: true,
+              control: false,
+              alt: false,
+              shift: false,
+            },
+          ),
+        );
+        assert.doesNotThrow(() => inputEvent({}, { type: "gestureScrollEnd" }));
+      }).pipe(Effect.provide(layer));
+    }),
+  );
+
   // Chromium hands the main window's zoom level down to embedded preview
   // guests, so every app zoom has to put the preview browser back at its own
   // zoom or zooming the UI drags the previewed page with it.

apps/desktop/src/window/DesktopWindow.ts

@@ -705,6 +705,7 @@ export const make = Effect.gen(function* () {
     });
     window.webContents.on("before-input-event", (event, input) => {
       quitShortcutHandler(event, input);
+      if (window.isDestroyed()) return;
       // Cmd/Ctrl+W reaches the renderer; DevTools uses the native menu shortcut.
       window.webContents.setIgnoreMenuShortcuts(
         (environment.platform === "darwin" ? input.meta : input.control) &&
@@ -720,6 +721,7 @@ export const make = Effect.gen(function* () {
       }
     });
     window.webContents.on("input-event", (_event, input) => {
+      if (window.isDestroyed()) return;
       if (input.type === "gestureScrollBegin") {
         window.webContents.send(TRACKPAD_SCROLL_BEGIN_CHANNEL);
       } else if (input.type === "gestureScrollEnd") {