tester

Unit testing isolates and validates individual functions or components in your codebase. Use Jest for JavaScript/TypeScript or pytest for Python to write tests that verify each piece works correctly. This Skill provides AAA-pattern templates and runnable examples to scaffold your first test suite quickly.

Unit tests verify individual components in isolation. Integration tests validate interactions between modules. End-to-end tests confirm complete user workflows from start to finish. This Skill guides you through all three levels and provides framework-specific examples for Jest, Vitest, pytest, Cypress, and Playwright.

Yes. Jest handles JavaScript/TypeScript testing; pytest handles Python testing. This Skill supports both frameworks within polyglot projects, offering templates and best-practice guidance for each language so your test strategies remain consistent.

Follow the AAA pattern—Arrange, Act, Assert—to write focused, maintainable tests that verify behavior rather than implementation details. This Skill provides mock data scaffolds and test templates that reduce brittleness and help your test suite remain robust as your codebase evolves.

Yes. This Skill covers end-to-end testing with both Cypress and Playwright, guiding you through user-flow validation and providing ready-to-run templates for browser automation across JavaScript/TypeScript projects.

Without tests, regressions—bugs introduced by new changes—go undetected until users report them. Automated testing catches these early. This Skill helps you add comprehensive test coverage to new features so existing behavior remains protected.