javascript-testing-patterns

Unit testing async operations in JavaScript involves resolving or rejecting promises within your test cases to verify behavior. This Skill provides patterns for handling asynchronous code using Jest and Vitest to ensure robust application development.

Mocking modules in Vitest is achieved through dependency injection and function spying to isolate the test subject from external dependencies. This Skill covers specific techniques for mocking modules to ensure reliable and isolated test execution.

Testing React components and custom hooks with Testing Library involves querying the DOM as users interact with it to verify component behavior. This Skill provides frontend testing patterns to capture UI changes and validate hook logic effectively.

Jest can be used for API and database integration testing to verify system interactions and endpoint connectivity. This Skill demonstrates how to perform integration tests to validate that your API endpoints and databases work together correctly.

Generating consistent test data using fixtures and Faker involves creating factory functions to produce mock data objects for your tests. This Skill covers test fixtures and factories to maintain reliable and repeatable test inputs.

Snapshot testing should be used to capture and compare component snapshots to detect unintended UI changes in React components. This Skill explains how to implement snapshot testing to prevent visual regressions during development.