9 React Testing Best Practices for Better Design and Quality of Your Tests

The post argues that better React tests are smaller, clearer, and more closely tied to behavior. It recommends starting with the happy path, then adding edge cases and errors, while keeping snapshots limited and removing tests that no longer add value.

Reading notes

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• Use the Arrange-Act-Assert pattern to make tests easier to read, follow, understand, and maintain.
• Keep each test focused on one specific behavior instead of testing several functions at once.
• Treat snapshot tests carefully, use them mainly for small stateless UI components or stable critical components, and keep them small and focused.
• Start by testing the most common use case before moving to edge cases and error states.
• Test edge cases such as invalid inputs, delayed requests, and server errors after the core behavior works.
• Give more weight to integration tests because they cover how parts of the application work together and can catch issues unit tests miss.
• Test how your code uses third-party libraries instead of testing the library internals.
• Do not write tests only to increase coverage percentage; write tests that verify real behavior and functionality.
• Review tests regularly and delete the ones that are redundant, irrelevant, or tied to removed features.