Test-Driven Development Process
This process can be classified into three phases which eventually form the cycle of TDD.
1. Red Phase
The red phase means to write a unit test case to test the software. In the software domain, any algorithm for any problem must be correct and directly writing an algorithm does not mean it is correct. So the question comes of how we will verify our algorithm. That is where the test cases (examples) come into the picture. By the test cases only, we can determine whether the software is working on all the possible conditions or not.
2. Green Phase
Green phase means to pass that test case i.e. to compile the case. After taking some test cases and running the software on them, it may not be the case that the software is not able to give the correct answer. So In the green, we try to pass all the test cases based on different conditions and situations so that in the future it(software) should work on all the cases no matter how hard it is.
3. Refactoring Phase
The Refactoring phase means to optimize and fix the errors if the software has any. Let’s say after running all the test cases we found some errors, they may be syntactical, logical, etc. types of errors, now the question arises of how to correct it. So here the refactoring phase of the TDD helps developers to overcome this situation. The developers try to fix the errors and optimize the code (according to time and space complexity) as much as possible so that it can be as quick as possible. The developers then follow the same phases again starting right from red then green and at last refactoring until all errors are fixed and the code is optimized.
After the refactoring phases i.e. when the code is optimized and the errors get fixed the code again follows the Red green and refactoring phase until and unless it works on all cases properly and correctly.
This can be shown in the image below:
The Importance of Test-Driven Development (TDD)
Development is the leader of the market at present. Those who know development are earning and growing in their life. Suppose a developer develops a website or app in a company then we think that yes the developer has developed it and it is correct and has no errors. But actually, the app website or software we see is Test-Driven Development (TDD) Software.