Testing JavaScript Applications

Testing JavaScript Applications teaches you how to implement an automated testing plan for JavaScript-based web applications. Summary Automated testing will help you write high-quality software in less time, with more confidence, fewer bugs, and without constant manual oversight. Testing JavaScript Applications is a guide to building a comprehensive and reliable JS application testing suite, covering both how to write tests and how JS testing tools work under the hood. You’ll learn from Lucas de Costa, a core contributor to popular JS testing libraries, as he shares a quality mindset for making testing decisions that deliver a real contribution to your business. You’ll benefit from informative explanations and diagrams, easily-transferable code samples, and useful tips on using the latest and most consolidated libraries and frameworks of the JavaScript ecosystem. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the technology Automated testing is essential to delivering good JavaScript applications every time. A complete testing strategy needs to cover functions in isolation, integration between different parts of your code, and correctness from the end user’s perspective. This book will teach you how to deliver reliable software quickly and confidently. About the book Testing JavaScript Applications teaches you how to implement an automated testing plan for JavaScript-based web applications. It describes practical testing strategies, covers useful tools and libraries, and explains how to foster a culture of quality. In this clearly-written, example-rich book, you’ll explore approaches for both backend and frontend applications and learn how to validate your software much more quickly and reliably. What's inside Unit, end-to-end, and integration testing Managing test cost and complexity Practicing test-driven development Dealing with external dependencies Tools like like Jest and Cypress About the reader For junior JavaScript developers. About the author Lucas da Costa is a core maintainer of Chai and Sinon.JS, two of the most popular testing tools in the JavaScript ecosystem, and contributed to numerous other open-source projects, including Jest. Table of Contents PART 1 - TESTING JAVASCRIPT APPLICATIONS 1 An introduction to automated testing 2 What to test and when? Part 2 - WRITING TESTS 3 Testing techniques 4 Testing backend applications 5 Advanced backend testing techniques 6 Testing frontend applications 7 The React testing ecosystem 8 Testing React applications 9 Test-driven development 10 UI-based end-to-end testing 11 Writing UI-based end-to-end tests PART 3 - BUSINESS IMPACT 12 Continuous integration and continuous delivery 13 A culture of quality Testing JavaScript Applications is a guide to creating JavaScript tests that are targeted to your applications specific needs. Dripping with the insight author Lucas da Costa has developed as a core contributor to some of the most popular JS testing libraries, this book offers dozens of detailed code samples that you can apply to your own projects. Youll learn how to write tests for both backend and frontend applications, covering the full spectrum of testing types so you can pick an approach thats right for you. Taking on the role of a developer for a bakerys web store, youll learn to validate different aspects including databases, third-party services, and how to spin-up a real browser instance to interact with the entire application. All examples are delivered using the popular testing tool Jest and modern packages of the JavaScript ecosystem. 2 What to test and when? -- 2.1 The testing pyramid -- 2.2 Unit tests -- 2.3 Integration tests -- 2.4 End-to-end tests -- 2.4.1 Testing HTTP APIs -- 2.4.2 Testing GUIs -- 2.4.3 Acceptance tests and end-to-end tests are not the same -- 2.5 Exploratory testing and the value of QA -- 2.6 Tests, cost, and revenue -- Summary -- Part 2. Writing tests -- 3 Testing techniques -- 3.1 Organizing test suites -- 3.1.1 Breaking down tests -- 3.1.2 Parallelism -- 3.1.3 Global hooks -- 3.1.4 Atomicity -- 3.2 Writing good assertions -- 3.2.1 Assertions and error handling -- 3.2.2 Loose assertions