fix(desktop): share screenshot deadline across paint and capture

packages/desktop/src/features/browser-automation/service.test.ts

@@ -67,6 +67,7 @@ class FakeTab implements TabContents {
   public networkEntries: unknown[] = [];
   public consoleMessages: BrowserAutomationConsoleLogEntry[] = [];
   public dialogsToCapture: BrowserAutomationDialogEvent[] = [];
+  public paintDelayMs = 0;
   public captureNeverPaints = false;
   public captureThrows = false;
   public captureErrorMessage = "capture failed";
@@ -118,6 +119,9 @@ class FakeTab implements TabContents {
 
   public async executeJavaScript(code: string): Promise<unknown> {
     this.scripts.push(code);
+    if (code.includes("requestAnimationFrame") && this.paintDelayMs > 0) {
+      await new Promise((resolve) => setTimeout(resolve, this.paintDelayMs));
+    }
     if (code.includes("document.body.innerText")) {
       return this.bodyText;
     }
@@ -1591,6 +1595,31 @@ describe("executeAutomationCommand", () => {
     }
   });
 
+  test("paint and pixel capture share the five-second screenshot budget", async () => {
+    vi.useFakeTimers();
+    try {
+      const browser = new BrowserAutomationHarness();
+      browser.tab.paintDelayMs = 4_000;
+      browser.tab.captureNeverPaints = true;
+      let result: unknown;
+      void browser
+        .execute({
+          command: "screenshot",
+          args: { browserId: BROWSER_A },
+        })
+        .then((value) => {
+          result = value;
+          return value;
+        });
+      await vi.advanceTimersByTimeAsync(4_999);
+      expect(result).toBeUndefined();
+      await vi.advanceTimersByTimeAsync(1);
+      expect(result).toMatchObject({ ok: false, error: { code: "screenshot_no_frame" } });
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   test("screenshot surfaces ordinary viewport capture errors", async () => {
     const browser = new BrowserAutomationHarness();
     browser.tab.captureThrows = true;

packages/desktop/src/features/browser-automation/service.ts

@@ -162,8 +162,8 @@ async function runSerializedPixelCapture<T>(capture: () => Promise<T>): Promise<
 async function capturePixelFrameWithRetry<T>(
   contents: TabContents,
   capture: () => Promise<T>,
+  deadline: number,
 ): Promise<T> {
-  const deadline = Date.now() + PIXEL_CAPTURE_TIMEOUT_MS;
   while (Date.now() < deadline) {
     try {
       contents.invalidate();
@@ -190,13 +190,14 @@ function isKnownNoFrameCaptureError(error: unknown): boolean {
   );
 }
 
-async function waitForPaint(contents: TabContents): Promise<void> {
+async function waitForPaint(contents: TabContents, deadline: number): Promise<void> {
   // A hidden page may have unpainted DOM updates. The first animation callback
   // precedes paint; the next frame ensures capture cannot reuse the old surface.
   await withPixelCaptureTimeout(
     contents.executeJavaScript(
       "new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(() => resolve())))",
     ),
+    deadline - Date.now(),
   );
 }
 
@@ -206,8 +207,9 @@ async function runPaintedPixelCapture<T>(
 ): Promise<T> {
   return runSerializedPixelCapture(() =>
     contents.withFrameProduction(async () => {
-      await waitForPaint(contents);
-      return capturePixelFrameWithRetry(contents, capture);
+      const deadline = Date.now() + PIXEL_CAPTURE_TIMEOUT_MS;
+      await waitForPaint(contents, deadline);
+      return capturePixelFrameWithRetry(contents, capture, deadline);
     }),
   );
 }