Open loaded Linux desktop windows when hidden rendering stalls (#6726)

* fix(desktop): show the window when ready-to-show never fires on Linux

Reveal hidden Linux windows that do not receive an initial compositor frame.

* fix(desktop): open loaded Linux windows without waiting for a frame

A hidden Linux window can finish loading without painting, so waiting only for ready-to-show leaves the application invisible. Reveal the loaded document and retain the frame-ready path on other platforms.

Co-authored-by: mistop <jhlim@mistop.org>

---------

Co-authored-by: mistop <jhlim@mistop.org>
Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>

docs/development.md

@@ -311,6 +311,22 @@ frames non-stop, pinning ProMotion displays at 120Hz forever and draining the
 battery while the app is idle — so do not re-add it. The probe's visibility
 guards already prevent throttling from causing a false stall.
 
+### Desktop Linux hidden-window fallback
+
+On Wayland (seen on ChromeOS Linux) a window created with `show: false` can sit
+forever without a single compositor frame: the renderer loads and runs, but
+`ready-to-show` never fires, so the window is never shown and the app looks like
+it did not start while every process is alive. `showWindowWhenReady`
+(`packages/desktop/src/window/show-when-ready.ts`) shows the main window when
+the document finishes loading if the event has not arrived. The fallback is
+Linux-only; macOS and Windows keep waiting for `ready-to-show`.
+
+Run the startup regression on Linux with an isolated display:
+
+```bash
+xvfb-run -a npm run test:e2e:window-startup --workspace=@getpaseo/desktop
+```
+
 ### Daemon logs
 
 Check `$PASEO_HOME/daemon.log` for daemon logs. The default level is `info`; set

packages/desktop/e2e/window-startup.e2e.mjs

@@ -0,0 +1,48 @@
+import { mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { _electron as electron, expect } from "playwright/test";
+
+const root = await mkdtemp(path.join(tmpdir(), "paseo-window-startup-"));
+const modulePath = fileURLToPath(new URL("../dist/window/show-when-ready.js", import.meta.url));
+
+async function launchWindowWithoutHiddenFrames() {
+  const main = path.join(root, "main.cjs");
+  await writeFile(
+    main,
+    `const { app, BrowserWindow } = require("electron");
+     const { showWindowWhenReady } = require(${JSON.stringify(modulePath)});
+     app.setPath("userData", ${JSON.stringify(path.join(root, "user-data"))});
+     app.whenReady().then(async () => {
+       const win = global.mainWindow = new BrowserWindow({ show: false, paintWhenInitiallyHidden: false });
+       showWindowWhenReady(win, { showOnLoad: true });
+       await win.loadURL("data:text/html,<h1>Desktop ready</h1>");
+       global.visibleAfterLoad = win.isVisible();
+     });`,
+  );
+  const env = Object.fromEntries(
+    Object.entries(process.env).filter(([key]) => key !== "ELECTRON_RUN_AS_NODE"),
+  );
+  const displayArgs = process.platform === "linux" ? ["--ozone-platform=x11", "--disable-gpu"] : [];
+  return electron.launch({
+    args: ["--no-sandbox", ...displayArgs, main],
+    env,
+  });
+}
+
+async function expectLoadedDesktopIsShown(desktop) {
+  await expect.poll(() => desktop.evaluate(() => global.visibleAfterLoad)).toBe(true);
+  const page = await desktop.firstWindow();
+  await expect(page.getByRole("heading", { name: "Desktop ready" })).toBeVisible();
+}
+
+let desktop;
+try {
+  desktop = await launchWindowWithoutHiddenFrames();
+  await expectLoadedDesktopIsShown(desktop);
+  console.log("Loaded desktop is visible without hidden compositor frames");
+} finally {
+  await desktop?.close();
+  await rm(root, { recursive: true, force: true });
+}

packages/desktop/package.json

@@ -25,7 +25,8 @@
     "verify:electron-cdp": "node ./scripts/verify-electron-cdp.mjs",
     "test": "install-electron && vitest run --exclude \"e2e/**\"",
     "typecheck": "tsgo --noEmit -p tsconfig.json",
-    "test:e2e:lifecycle": "npm run build:main && node ./e2e/daemon-lifecycle.e2e.mjs"
+    "test:e2e:lifecycle": "npm run build:main && node ./e2e/daemon-lifecycle.e2e.mjs",
+    "test:e2e:window-startup": "npm run build:main && node ./e2e/window-startup.e2e.mjs"
   },
   "dependencies": {
     "@getpaseo/cli": "*",

packages/desktop/src/main.ts

@@ -43,6 +43,7 @@ import {
   buildStandardContextMenuItems,
 } from "./window/window-manager.js";
 import { setupDarwinCompositorWatchdog } from "./window/compositor-watchdog/index.js";
+import { showWindowWhenReady } from "./window/show-when-ready.js";
 import { resolveDesktopWindowChromeMode, windowChromeModeArgument } from "./window/chrome.js";
 import { registerDialogHandlers } from "./features/dialogs.js";
 import {
@@ -773,8 +774,8 @@ async function createWindow(
     registerBrowserWebviewNavigationGuards(contents);
   });
 
-  mainWindow.once("ready-to-show", () => {
-    mainWindow.show();
+  showWindowWhenReady(mainWindow, {
+    showOnLoad: process.platform === "linux",
   });
 
   if (!app.isPackaged) {

packages/desktop/src/window/show-when-ready.test.ts

@@ -0,0 +1,57 @@
+import { EventEmitter } from "node:events";
+import { describe, expect, it } from "vitest";
+import { showWindowWhenReady } from "./show-when-ready.js";
+
+class Window extends EventEmitter {
+  webContents = new EventEmitter();
+  shows = 0;
+  destroyed = false;
+  show() {
+    this.shows += 1;
+  }
+  isDestroyed() {
+    return this.destroyed;
+  }
+  close() {
+    this.destroyed = true;
+    this.emit("closed");
+  }
+}
+
+describe("showWindowWhenReady", () => {
+  it("shows a loaded Linux window even when no initial frame was painted", () => {
+    const win = new Window();
+    showWindowWhenReady(win, { showOnLoad: true });
+    expect(win.shows).toBe(0);
+    win.webContents.emit("did-finish-load");
+    expect(win.shows).toBe(1);
+    win.emit("ready-to-show");
+    expect(win.shows).toBe(1);
+  });
+
+  it("shows on the first frame without showing again after load", () => {
+    const win = new Window();
+    showWindowWhenReady(win, { showOnLoad: true });
+    win.emit("ready-to-show");
+    win.webContents.emit("did-finish-load");
+    expect(win.shows).toBe(1);
+  });
+
+  it("preserves waiting for the initial frame when show on load is disabled", () => {
+    const win = new Window();
+    showWindowWhenReady(win, { showOnLoad: false });
+    win.webContents.emit("did-finish-load");
+    expect(win.shows).toBe(0);
+    win.emit("ready-to-show");
+    expect(win.shows).toBe(1);
+  });
+
+  it("keeps a closed window closed when readiness arrives later", () => {
+    const win = new Window();
+    showWindowWhenReady(win, { showOnLoad: true });
+    win.close();
+    win.webContents.emit("did-finish-load");
+    win.emit("ready-to-show");
+    expect(win.shows).toBe(0);
+  });
+});

packages/desktop/src/window/show-when-ready.ts

@@ -0,0 +1,25 @@
+interface ReadyToShowWindow {
+  once(event: "ready-to-show", listener: () => void): unknown;
+  webContents: {
+    once(event: "did-finish-load", listener: () => void): unknown;
+  };
+  show(): void;
+  isDestroyed(): boolean;
+}
+
+export function showWindowWhenReady(
+  win: ReadyToShowWindow,
+  options: { showOnLoad: boolean },
+): void {
+  let shown = false;
+  const show = () => {
+    if (shown || win.isDestroyed()) return;
+    shown = true;
+    win.show();
+  };
+
+  win.once("ready-to-show", show);
+  // On Linux a hidden window can wait for compositor frames until it is shown.
+  // Loading the document is sufficient to reveal it without depending on a frame.
+  if (options.showOnLoad) win.webContents.once("did-finish-load", show);
+}