fix: repair four pre-existing failing test suites

[natashaannn]

Fix pre-existing failing test suites

Background

Four test suites were failing before this branch was created. All four cover live production features. This PR fixes each one, migrates the misplaced integration test to the correct location per TESTING_STANDARDS.md, and resolves two related test-infrastructure issues found during review.

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What was broken and why

CaptionExtractor.test.js

The suite failed to run due to a stale mock path for the youtube-transcript module. Updated the mock target and restructured the beforeEach setup so the HTML-parsing fallback path is exercised by default.

generate-carousel.test.js — import.meta SyntaxError

generate-carousel.js uses import.meta.url to detect whether it is the CLI entry point. Babel's @babel/plugin-syntax-import-meta only parses import.meta — it leaves it in the CJS output, so Node throws SyntaxError: Cannot use 'import.meta' outside a module at test time.

• Replaced the syntax-only plugin with babel-plugin-transform-import-meta, which rewrites import.meta.url to require('url').pathToFileURL(__filename).
• Changed the ESM guard in generate-carousel.js from typeof import.meta !== 'undefined' (un-transformable) to typeof require === 'undefined' so the guard short-circuits at runtime in CJS/Jest before the right-hand side is evaluated.

CarouselGenerator.test.js — six failures from source/test drift

The source was refactored (switched from puppeteer-extra to plain puppeteer, simplified frame-extraction logic, added options to page.goto) but the tests were not updated.

Failure	Root cause	Fix
init — mockBrowser.launch not a function	init() calls await import('puppeteer') but only puppeteer-extra was mocked	Added jest.mock('puppeteer'); set launch via jest.requireMock in beforeEach
generateCtaSlide — fetch not called	Source reads thumbnail from thumbnailPath via fs.readFile, not from a URL via fetch	Updated test config and assertion to use thumbnailPath / fs.readFile
goto assertion fails	Source now calls page.goto(url, { waitUntil: 'load', timeout: 60000 })	Updated assertion to toHaveBeenCalledWith(stringContaining(...), expect.any(Object))
seekAndExtractFrame null crash	screenshot() returning null hit elementShot.length before the retry continue	Added null guard in CarouselGenerator.js; retries correctly
Wrong error message	Expected 'Could not extract video frame'; source throws 'Could not extract a non-blank video frame'	Updated expected substring
Stale "video reset / YouTube error" tests	Tested reload and hasErrorElements logic removed from source	Rewrote to test real current behaviour: null-screenshot retry and video-element-not-found

transcript-caption.test.js — wrong location

The test reads public/transcribe/output/transcript.json from disk — real I/O. Per TESTING_STANDARDS.md, tests with real file I/O belong in tests/integration/, not next to source files. Moved and added the fixture transcript.json it depends on.

tests/setup.js — parallel-Jest ENOENT race

The shared Jest setup had beforeAll/afterAll hooks that created and deleted a test-output/ directory. No test file ever read or wrote to that directory. Under parallel Jest execution this caused a non-deterministic race: one suite's afterAll would delete the directory while another suite's beforeAll was still creating it, producing intermittent ENOENT failures in edit-transcript.test.js. Removed the dead infrastructure entirely.

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Files changed

File	Change
.babelrc	Swap syntax-only plugin → babel-plugin-transform-import-meta transform plugin; restore trailing newline
package.json / package-lock.json	Add babel-plugin-transform-import-meta dev dependency
scripts/carousel/generate-carousel.js	Replace typeof import.meta guard with typeof require === 'undefined'
scripts/carousel/CarouselGenerator.js	Null-guard screenshot() result; fix unused catch bindings
scripts/__tests__/CaptionExtractor.test.js	Fix mock path; restructure beforeEach
scripts/__tests__/CarouselGenerator.test.js	Align mocks and assertions with current source
scripts/__tests__/generate-carousel.test.js	No logic changes — now parses cleanly with the transform plugin
tests/integration/transcript-caption.test.js	Moved from scripts/transcript-caption.test.js
tests/setup.js	Remove dead test-output/ lifecycle that caused parallel-Jest ENOENT race
public/transcribe/output/transcript.json	Fixture for integration test regression cases
remotion/Root.tsx	Lint-staged artifact: eslint-disable comment relocated closer to usage (cosmetic, ESLint-clean)
remotion/components/SegmentPlayer.tsx	Lint-staged artifact: dead eslint-disable-next-line no-console comments removed; whitespace-only replacement lines cleaned up (ESLint-clean)

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Test plan

• npm test — all 230 tests across all suites pass (2 pre-existing skips)
• npx tsc --noEmit — no type errors
• npx eslint --max-warnings=0 on changed files — clean
• Pre-commit hook runs lint-staged + jest --findRelatedTests without errors

Issues

Closes #64