Testing

Catch bugs before your users do.

Testing tools here range from unit test runners to full end-to-end browser testing frameworks that simulate real user flows. Which layer matters most depends on the app: a UI-heavy product benefits more from end-to-end coverage, while a library benefits more from thorough unit tests. Pick based on what actually breaks in your app, not on covering every layer equally.

Cypress

Playwright's longer-running rival for E2E testing. Still solid, particularly if your team already has Cypress test suites and tooling built up.

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Jest

Still the safe default for unit testing in a lot of existing Node/React codebases. Huge ecosystem of docs and Stack Overflow answers if something breaks.

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Playwright

The default pick for end-to-end browser testing now. Fast, handles multiple browsers, and its trace viewer makes debugging a flaky test much less painful.

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Testing Library

Not a runner itself, but the query API (getByRole, getByText) that keeps you testing what a user actually sees instead of implementation details.

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Vitest

Unit test runner that reuses your Vite config, so if your app already builds with Vite, tests just run without a separate Jest config to maintain.

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