Add MP4 Electron export E2E

[yusufm]

Summary

• add a Playwright Electron MP4 export test that validates the saved MP4 bytes
• share Electron E2E helpers for save interception, fixture setup, and deterministic shutdown
• run Electron E2E serially to avoid shared Electron userData collisions
• add an MP4 format test id and fix the linted hook dependency used by CI

Testing

• npm run lint
• npm run build-vite
• npm run test:e2e
• npm run test:browser

Summary by CodeRabbit

• Tests

  • Added end-to-end MP4 export test with file validation.
  • Refactored GIF export tests to use shared test utilities.
  • Added e2e helpers for app lifecycle and export interception.

• New Features

  • MP4 export format control now includes a test identifier for UI testing.

• Chores

  • Ensured test runner uses a single worker.
  • Improved screen-recording cleanup behavior.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 135457a1-bf15-426a-92a0-b793e9486c0d

📥 Commits

Reviewing files that changed from the base of the PR and between 15316d9 and 251b29b.

📒 Files selected for processing (2)

• tests/e2e/helpers.ts
• tests/e2e/mp4-export.spec.ts

✅ Files skipped from review due to trivial changes (1)

• tests/e2e/mp4-export.spec.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• tests/e2e/helpers.ts

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📝 Walkthrough

Walkthrough

This PR adds shared Playwright/Electron e2e helpers, a new MP4 export test, refactors the GIF export test to use those helpers, memoizes a recorder helper in useScreenRecorder, adds a test-id to the MP4 format button, and forces Playwright to run with a single worker.

Changes

MP4 Export E2E Testing Infrastructure

Layer / File(s)	Summary
Test IDs / type src/utils/getTestId.ts, src/components/video-editor/SettingsPanel.tsx	TestId union reformatted; MP4 export button gains data-testid={getTestId("mp4-format-button")}.
Hook / Cleanup src/hooks/useScreenRecorder.ts	safeHideCountdownOverlay memoized with useCallback; recording cleanup effect now depends on safeHideCountdownOverlay and teardownMedia.
Test Helpers tests/e2e/helpers.ts	Adds waitForProcessExit, closeElectronApp, interceptExportSave, copyFixtureToRecordings, and readCapturedExportBuffer to centralize IPC, fixture copying, and process teardown.
Tests (implementation/refactor) tests/e2e/mp4-export.spec.ts, tests/e2e/gif-export.spec.ts	New MP4 export e2e test validates intercepted export buffer (ftyp signature and size). GIF export test refactored to use shared helpers and readCapturedExportBuffer.

Test Configuration

Layer / File(s)	Summary
Playwright config playwright.config.ts	Sets workers: 1 in Playwright config to force single-worker test execution.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• Improve Arch Linux support and fix video export on Hyprland #484: touches Electron IPC export flow and the "save-exported-video" behavior that the new helpers intercept.
• fix(security): prevent path traversal in IPC file read handlers #352: overlaps on e2e fixture copying and test setup for using recordings fixtures.
• fix: resolve blurry screen recordings and video editor previews #419: modifies useScreenRecorder-adjacent logic (codec/preference changes), related to the hook cleanup edits here.

Suggested reviewers

• siddharthvaddem

Poem

night shift tests hum, a tiny electron glow,
helpers stitched up tidy, exports ebb and flow,
mp4 bytes whisper ftyp in the dark,
one worker trudges onward—steady, not stark,
low-key triumphant, we ship another spark.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title clearly summarizes the main change: adding an MP4 Electron export end-to-end test, which is the primary focus of this PR.
Description check	✅ Passed	Description covers all key changes with testing instructions, though it omits several template sections like Motivation and Type of Change checkboxes.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tests/e2e/helpers.ts`:
- Around line 62-66: Add a defensive guard in readCapturedExportBuffer: before
calling Buffer.from, retrieve the captured value from
globalThis["__testExportData"] (as currently done) and verify it is a non-empty
string (or Buffer-encodable value); if missing or invalid, throw a clear Error
mentioning that __testExportData was not set or is invalid so tests fail with a
helpful message. Update the function readCapturedExportBuffer to validate the
retrieved base64 value and only call Buffer.from(base64, "base64") when the
check passes.

In `@tests/e2e/mp4-export.spec.ts`:
- Around line 41-44: The test fires two IPC calls inside hudWindow.evaluate that
can race; change the evaluate callback so it awaits
window.electronAPI.setCurrentVideoPath(videoPath) before calling/awaiting
window.electronAPI.switchToEditor(), ensuring setCurrentVideoPath completes
first (i.e., use await on setCurrentVideoPath and then await switchToEditor
inside the hudWindow.evaluate callback) to eliminate the export-flow race.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c4a3bcbc-624d-4165-beb1-141318472a6c

📥 Commits

Reviewing files that changed from the base of the PR and between 7e00cdb and 15316d9.

📒 Files selected for processing (7)

• playwright.config.ts
• src/components/video-editor/SettingsPanel.tsx
• src/hooks/useScreenRecorder.ts
• src/utils/getTestId.ts
• tests/e2e/gif-export.spec.ts
• tests/e2e/helpers.ts
• tests/e2e/mp4-export.spec.ts