testing

Unit tests validate individual components in isolation. Use pytest to install the framework, write test functions in a test file, define fixtures for reusable test data, and run pytest from the command line to execute tests and report results.

Unit tests verify individual functions or classes in isolation. Integration tests validate how multiple components interact together. End-to-end tests check complete user workflows from start to finish across your entire application.

Jest is a testing framework for JavaScript. Install Jest via npm, create test files with .test.js extensions, write test cases using Jest's syntax, and run jest from the command line to execute tests and display coverage metrics.

Yes, both pytest and Jest generate code coverage reports showing which lines, branches, and functions your tests exercise. Run pytest --cov or jest --coverage to identify untested code paths and gaps in your test strategy.

Mocking patches external services, APIs, or dependencies so tests run in isolation. pytest and Jest provide built-in mocking tools to replace real implementations with test doubles, allowing you to control behavior and verify interactions without external calls.

Yes, pytest and Jest are framework dependencies installed per project. Add them to your project's package manager (pip for Python, npm for JavaScript), then configure them in your project to discover and run tests automatically.