If there’s one thing that both large and small organizations desire, it’s to create a product that drives a tangible business result.  
When this is the goal, the term TDD or Test Driven Development can often be seen discussed by developers and management alike. 
If you’re new to the term TDD or less familiar with the concept, here’s a concrete guide to help you understand TDD, its process, benefits, and much more. 
Let’s go! 

What is TDD?

Test-Driven Development (TDD) refers to the practice of writing a piece of code only if the automated test has failed. 
The approach states that one should write “implementation code” only if there is a “failing test case”. It is an iterative approach for developing software products where –
A failing test case is writtenEnough business code is created which makes the failing test case passThen, if needed, the entire code is refactored.Finally, the entire process is repeated, creating more tests over a period of time. 

Understanding the TDD Process

Here is a step by step process demonstrating how TDD works- 
1. Run a test and see if it fails: Write a unit function for the test that will be implemented. The test shouldn’t be too long and should be enough to focus on only one behavior of the function. Write minimal code that meets the requirements. It’s now time to run the test and check if it fails. 
A test that shows a negative result means you’re on the correct track and it was no beginner’s luck. Failure here is good.
2. Write the correct code that delivers a positive result: Write the bare minimum supporting code that is correct enough to pass the test. If the code makes the cut, move on. Do the test again and confirm if it passes. 
3. Refactor till needed: After passing the test, start refactoring without splitting the code. Evaluate the code and look for areas of improvement to ensure the code is clean. Eliminate duplicate code by adding new features. Strengthen the design system to power up solutions. 
Once finished with refactoring and run the tests again so that you pass. Repeat until no longer required.
To view the full blog and this blog "Benefits Of Test-Driven Development" is originally published on Agilemania website.