Test-Driven Development

Introduction to test-driven development (TDD)

Test-driven development (TDD) is a software development approach where tests are written before the implementation code. The development process revolves around an iterative cycle of writing a failing test, implementing the code to make the test pass, and then refactoring the code.

Some of the benefits of test-driven development are the following:

• Improved code quality: TDD encourages developers to write focused and specific tests, leading to more robust and reliable code.

• Faster feedback loop: By writing tests first, developers quickly receive feedback on their code’s correctness and can detect issues early.

• Increased test coverage: TDD promotes writing tests for all code paths, resulting in comprehensive test coverage.

• Better design and modularity: Writing tests upfront forces developers to think about the code’s design, resulting in cleaner and more modular architectures.

• Code maintainability: TDD promotes writing testable code, making it easier to maintain and refactor code over time.

The red-green-refactor cycle

The core of TDD is the red-green-refactor cycle, which involves three steps:

1. Red: Writing a failing test.

2. Green: Implementing the code to make the test pass.

3. Refactor: Refactoring the code to improve its design and maintainability.

This cycle is repeated for each new feature or behavior to be implemented.

Writing the initial test expected to fail

We begin by identifying a small, incremental functionality or behavior to implement. We then write a test that clearly defines the ...