Question 1

What does React Testing Library encourage?

Accepted Answer

Testing user-visible behavior via accessible queries rather than internals. Prefer getByRole/text. Avoid testing implementation details like state values.

Question 2

How do you test asynchronous UI updates?

Accepted Answer

use findBy*, waitFor, and ensure promises flush; mock network. Avoid arbitrary setTimeout. Assert loading and success states.

Question 3

Unit vs integration vs e2e for React?

Accepted Answer

Unit for hooks/utils; integration for components with providers; e2e for critical flows. Balance cost. Mock at boundaries thoughtfully.

Question 4

How do you mock useRouter / navigation in tests?

Accepted Answer

Mock the framework module or wrap with a memory router provider. Keep tests resilient to minor API changes by abstracting navigation helpers.

Testing React Interview Questions

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