When you build some functionality, you have to test that the functionality works like you would expect it. Testing is usually done at the end of your project and this can be automated.
With a unit test, we can specify what a specific part of code needs to do. What will be the input, how will it be processed, what is the output—these are all the things that you can specify in a unit test.
A new addition to Magento 2 is that unit tests are automatically included in the core. When you want to contribute to the Magento core with GitHub, it is required that your changes pass through the unit and integration tests.
For running the unit tests, we need the command-line tool of Magento. Ensure that you have ...