What is Test Driven Development?

Test Driven Development (TDD) is a software development process that focuses on writing tests before writing code. It is an iterative process that helps developers create better code faster and with fewer errors. In this article, we’ll discuss the basics of TDD and how to get started with it.?

The first step in TDD is to write a test for the feature you want to develop. This test should be written before any code is written and should describe the expected behavior of the feature. The test should also include any edge cases or special conditions that need to be taken into account. Once the test is written, it can be run against the existing codebase to make sure it fails as expected.?

The next step is to write the code necessary to make the test pass. This code should be written in small increments, with each increment tested against the existing tests before moving on to the next one. This helps ensure that each piece of code works as expected and that no bugs are introduced during development.?

Once all of the tests have been passed, it’s time for refactoring. Refactoring involves restructuring existing code without changing its behavior or functionality. This helps keep your codebase clean and maintainable over time.?

Finally, you should run all of your tests again after refactoring to make sure nothing was broken during refactoring. If everything passes, then you can deploy your new feature!?

For example, let’s say you want to create a function in JavaScript that takes two numbers and returns their sum. The first step would be to write a test for this function. The test might look something like this:?

// Test for sum function

const result = sum(2, 3);?

expect(result).toBe(5);??        

Next, you would write the code necessary to make the test pass. This might look something like this:?

// Sum function

function sum(a, b) {?

return a + b;?

}??        

Finally, you would run all of your tests again after refactoring to make sure nothing was broken during refactoring. If everything passes, then you can deploy your new feature!?

Test Driven Development is an invaluable tool for software developers and can help ensure quality code and fewer bugs in your applications. By following these steps, you can get started with TDD quickly and easily!