Learning test-driven development : a polyglot guide to writing uncluttered code

Your code is a testament to your skills as a developer. No matter what language you use, code should be clean, elegant, and uncluttered. By using test-driven development (TDD), you'll write code that's easy to understand, retains its elegance, and works for months, even years, to come. With this indispensable guide, you'll learn how to use TDD with three different languages: Go, JavaScript, and Python. Author Saleem Siddiqui shows you how to tackle domain complexity using a unit test-driven approach. TDD partitions requirements into small, implementable features, enabling you to solve problems irrespective of the languages and frameworks you use. With __Learning Test-Driven Development__ at your side, you'll learn how to incorporate TDD into your regular coding practice. This book helps you: * Use TDD's divide-and-conquer approach to tame domain complexity * Understand how TDD works across languages, testing frameworks, and domain concepts * Learn how TDD enables continuous integration * Support refactoring and redesign with TDD * Learn how to write a simple and effective unit test harness in JavaScript * Set up a continuous integration environment with the unit tests produced during TDD * Write clean, uncluttered code using TDD in Go, JavaScript, and Python Cover Copyright Table of Contents Foreword Preface What Is Test-Driven Development? A Technique Designing and Structuring Code A Bias Toward Simplicity Increased Confidence Who Is This Book For? What Are the Prerequisites for Reading This Book? How to Read This Book Follow the Book One Language at a Time Follow the Book in Two Languages First and Then in the Third Language Follow the Book in All Three Languages Simultaneously Conventions Used in This Book Typographical Conventions Lexical Conventions Using Code Examples How to Contact Us TDD—The Whys Why Does This Book Use Go, JavaScript, and Python? Why Not This Other Language? Why Does This Book Have a “Chapter 0”? Chapter 0: Introduction and Setup Setting Up Your Development Environment Common Setup Go JavaScript Python Where We Are Part I. Getting Started Chapter 1. The Money Problem Red-Green-Refactor: The Building Blocks of TDD What’s the Problem? Our First Failing Test Go JavaScript Python Going for Green Go JavaScript Python Cleaning Up Go JavaScript Python Committing Our Changes Where We Are Go JavaScript Python Chapter 2. Multicurrency Money Enter the Euro Go JavaScript Python Keeping Code DRY Go JavaScript Python Didn’t We Just Say “Don’t Repeat Yourself”?! Divide and Conquer Go JavaScript Python Cleaning Up Go JavaScript Python Committing Our Changes Where We Are Chapter 3. Portfolio Designing Our Next Test Go JavaScript Python Committing Our Changes Where We Are Part II. Modularization Chapter 4. Separation of Concerns Test and Production Code Unidirectional Dependency Dependency Injection Packaging and Deployment Modularization Removing Redundancy Where We Are Chapter 5. Packages and Modules in Go Separating Our Code into Packages Go Modules Creating a Package Encapsulation Removing Redundancy in Tests Committing Our Changes Where We Are Chapter 6. Modules in JavaScript Separating Our Code into Modules A Segue into JavaScript Modules CommonJS Asynchronous Module Definition (AMD) Universal Module Definition (UMD) ESModules Improving Our Tests Removing Redundancy in Tests Adding a Test Class and Test Methods Discovering and Running Tests Automatically Produce Output When Tests Run Successfully Run All Tests Even When an Earlier Test Assertion Fails Committing Our Changes Where We Are Chapter 7. Modules in Python Separating Our Code into Modules Removing Redundancy in Tests Committing Our Changes Where We Are Part III. Features and Redesign Chapter 8. Evaluating a Portfolio Mixing Money Go JavaScript Python Committing Our Changes Where We Are Chapter 9. Currencies, Currencies, Everywhere Making a Hash(map) of Things Go JavaScript Python Committing Our Changes Where We Are Chapter 10. Error Handling Error Wish List Go JavaScript Python Committing Our Changes Where We Are Chapter 11. Banking on Redesign Dependency Injection Putting It All Together Go JavaScript Python Committing Our Changes Where We Are Part IV. Finishing Up Chapter 12. Test Order Changing Exchange Rates Go JavaScript Python Committing Our Changes Where We Are Chapter 13. Continuous Integration Core Concepts Version Control Build Server and Agent Artifact Repository Deployment Environment Putting It All Together Create Your GitHub Account Verify Your GitHub Account Push Code Repository to GitHub Prepare for CI Build Scripts Go JavaScript Python Committing Our Changes Where We Are Chapter 14. Retrospective Profile Cyclomatic Complexity Coupling Succinctness Purpose Cohesion Completeness Process Putting It All Together Go JavaScript Python Isn’t TDD Dead? Where We Are Appendix A. Development Environment Setup Online REPLs Repl.it LeetCode CoderPad The Go Playground The Comprehensive List of Online REPLs Integrated Development Environments (IDEs) Visual Studio Code IntelliJ IDEA Eclipse Installing Language Tools Go JavaScript / ES6 Python Appendix B. A Brief History of the Three Languages Go JavaScript The assert Module The Module Mechanism Python Appendix C. Acknowledgments Index About the Author Colophon Your code is a testament to your skills as a developer. No matter what language you use, your code should be clean, elegant, and uncluttered? With test-driven development (TDD), you'll write better code--code that's easy to understand, retains its elegance, and works for years to come. This indispensable guide will show you how TDD works in three different languages: Go, JavaScript, and Python. With Learning Test-Driven Development at your side, you'll be able to: Tame domain complexity using a divide-and-conquer approach Understand how TDD works across languages, testing frameworks, and domain concepts See how TDD enables continuous integration and continuous delivery Support refactoring and redesign with TDD Set up a continuous integration environment with the unit tests produced during TDD Write clean, uncluttered code using TDD in Go, JavaScript, and Python