test(video-player): wait for widget after tab clicks, fix poster race

[samuelreichert]

Pull request type

Test related change (New E2E test, test automation, etc.)

---

Description

Fixes intermittent nightly failures in video-player-web E2E tests introduced after the e2e-reliability-and-performance merge.

Three root causes:

1. Tab page tests — after .click() on a tab, tests asserted toBeVisible() on iframes immediately. Mendix renders tab content asynchronously; the fixture's waitForMendixApp only patches page.goto, not tab navigation clicks. Added waitForWidget after each tab click.

2. Aspect ratio test — same tab-click race: boundingBox() called on elements in tabs 2 and 3 without waiting for them to be present in the DOM.

3. Poster screenshot — page.evaluate with a standalone new Image() resolves when the image loads into memory, not when the <video> element has painted the poster frame. Switched to videoLocator.evaluate(el => ...) to tie the wait to the actual element. Also added scrollIntoViewIfNeeded so the widget is in viewport before screenshotting.

[github-actions]

AI Code Review

⚠️ Approved with suggestions — low-severity items only, safe to merge

---

What was reviewed

File	Change
packages/pluggableWidgets/video-player-web/e2e/VideoPlayer.spec.js	Replaced waitForDataReady with waitForWidget in tab tests; replaced page.evaluate poster-wait approach with videoLocator.evaluate; added scrollIntoViewIfNeeded before screenshot

Skipped (out of scope): dist/, pnpm-lock.yaml

CI checks were unavailable during this review (command required manual approval). No failing checks were observed based on available information.

---

Findings

⚠️ Low — afterEach session logout not present

File: packages/pluggableWidgets/video-player-web/e2e/VideoPlayer.spec.js
Note: The skill guidelines require an afterEach session logout in every E2E file to avoid hitting Mendix's 5-session limit in CI. However, fixtures.mjs shows the page fixture already handles this automatically — await page.evaluate(() => window.mx?.session?.logout?.()).catch(() => {}) is called in the mendixSession worker-scoped teardown. This is fine as-is, but is worth documenting in the test file or the E2E guidelines to avoid confusion for future contributors who look for the explicit afterEach block.

---

⚠️ Low — Poster-load guard resolves on image decode, not on <video> paint

File: packages/pluggableWidgets/video-player-web/e2e/VideoPlayer.spec.js line 122–131
Note: The replacement approach — using videoLocator.evaluate to hook Image.onload — is significantly better than the previous waitForDataReady (which just polled networkidle). However, Image.onload fires when the image is fully decoded in memory, which is still not a guarantee that the browser has composited the poster frame into the video element's paint layer before Playwright takes the screenshot. A short waitForTimeout is an anti-pattern, but consider whether page.waitForFunction polling a canvas draw or an explicit page.clock.runFor(100) in the test env would be more deterministic if this screenshot continues to be flaky. This is a low-risk suggestion for a future iteration, not a blocker.

---

Positives

• Correctly switched from waitForDataReady (networkidle-based) to waitForWidget (locator-assertion-based) — this matches the E2E guidelines' preference for Playwright locator assertions over hardcoded waits.
• All tab-click tests now have a waitForWidget call immediately after .click(), eliminating the race condition between Mendix async tab rendering and the subsequent toBeVisible assertions.
• Selectors consistently use .mx-name-* pattern throughout — correct per the selector preference order in guidelines.
• Aspect ratio test was correctly updated to replace three toBeVisible polls with waitForWidget, ensuring DOM readiness before boundingBox() is called.
• PR description is detailed and accurately identifies three separate root causes with clear before/after reasoning.