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Testing and Debugging

Quality comes from layered confidence. A React Native team should know what is protected by unit tests, what is validated through component tests, what requires device-level automation, and how failures are diagnosed in production.

Testing layers​

Unit tests​

Use these for pure business logic, formatters, reducers, selectors, and transformation functions. They should be fast and deterministic.

Component tests​

Use these for screen behavior, accessibility states, loading and error surfaces, and user flows within a single screen.

End-to-end tests​

Use these for critical business journeys:

  • Authentication.
  • Purchase or checkout.
  • Core content creation.
  • Push notification re-entry.
  • Upgrade-sensitive routes.

Testing standards​

Document:

  • What must be tested before merge.
  • Which journeys are mandatory in end-to-end coverage.
  • Which mocks are allowed.
  • How to seed predictable test data.

Debugging workflow​

When an issue occurs:

  1. Reproduce it consistently.
  2. Classify whether it is JavaScript, native, network, or environment related.
  3. Capture logs, device context, and route state.
  4. Isolate the smallest failing path.
  5. Write or update a test if the bug is regressible.

Debugging tools to standardize​

  • JavaScript and component inspection.
  • Native logs from Android and iOS toolchains.
  • Crash reporting and breadcrumb trails.
  • Network inspection for API-heavy screens.
  • Build metadata so the team can map errors to app versions quickly.

Production diagnostics​

Testing alone is not enough. Production-ready apps also need:

  • Crash reporting.
  • Performance telemetry.
  • Release tagging.
  • Alerting for core flows.
  • A way to correlate user reports with shipped builds.

Quality anti-patterns​

  • Relying only on manual QA for core paths.
  • Writing brittle tests tied to implementation details.
  • Ignoring accessibility in test assertions.
  • Shipping without release metadata tied to crashes and logs.

Team rule​

If a bug matters enough to fix, it usually matters enough to improve detection for next time. Every incident should strengthen the system.

Next, define deployment and release operations.