Jest + TypeScript - Industry Standard Testing

What problem does it solve?

This Skill provides a comprehensive guide to using Jest, the industry-standard testing framework, for TypeScript projects, enabling developers to write reliable, maintainable, and efficient tests.

Core Features & Use Cases

• Setup & Configuration: Detailed instructions for jest.config.js and tsconfig.json.
• Core Patterns: Examples for basic tests, type-safe tests, and data-driven tests using .each.
• Mocking: Advanced techniques for module mocking (jest.mock), method spying (jest.spyOn), and type-safe mock functions.
• React Testing: Integration with React Testing Library for component and hook testing.
• Snapshot Testing: Strategies for UI regression testing and updating snapshots.
• Async Testing: Handling promises and callbacks effectively.
• Coverage: Configuring and running code coverage reports.
• Migration: Guidance on migrating from Vitest to Jest.
• Use Case: A developer needs to set up a robust testing suite for a new TypeScript React application, ensuring all components and utility functions are thoroughly tested with mocks and coverage reports.

Quick Start

Use the Jest skill to set up a new Jest configuration file for a TypeScript project.