Testing JavaScript (Node.js) Applications

Modern Node.js development is impossible without quality testing. The book "Testing JavaScript (Node.js) Applications" is a practical guide that will help you master all aspects of testing server-side and client-side JavaScript applications. From simple unit tests to complex end-to-end scenarios, you will learn to build a reliable code verification system.

The book is intended for JavaScript developers at Junior and Middle levels who are already familiar with the basics of Node.js and want to improve the quality of their projects. Experienced programmers will find the book helpful for systematizing their knowledge and getting acquainted with modern tools.

What you will learn:

• Testing fundamentals: testing pyramid, AAA pattern, mocks and stubs
• Unit testing: working with Jest and Mocha, testing functions, classes, and modules
• Integration testing: testing APIs with Supertest, working with databases and external services
• E2E testing: setting up Cypress, testing user scenarios
• Advanced techniques: TDD, BDD, snapshot testing, load testing
• CI/CD integration: configuring automatic test runs in GitHub Actions and Jenkins

The book contains many real code examples ready to use in your projects. Each chapter includes practical exercises to reinforce the material. You will learn not just to write tests, but to design testable application architecture.

Special attention is given to common mistakes made by beginner testers and ways to avoid them. The author shares proven patterns used in large production projects. After reading, you will be able to confidently implement testing in any Node.js project.

The book is suitable both for self-study and for use as a reference. All examples are compatible with the latest versions of Node.js 18+ and popular frameworks (Express, Koa, Fastify). Join the community of developers who write reliable code!