How To Write Unit Tests
First it initializes a small piece of an application it wants to test also known as the system under test or sut then it applies some stimulus to the system under test usually by calling a method on it and finally it observes the resulting behavior.
How to write unit tests. Good unit tests is essentially the specification in runnable form. A typical unit test contains 3 phases. The best way to understand unit testing is to simply try it on your next project. 1 3 more on go test. Write your unit tests to check if code will do what is expected then write the code then test it.
Break if the code tested change away from the specification. Even if you re a brilliant coder with decades of experience your existing knowledge and habits won t automatically lead you to write good unit tests because it s a different kind of coding and most people start with unhelpful false assumptions about. What s the difference between a good unit test and a bad one. The difference between unit and integration tests is that unit tests usually isolate dependencies that communicate with network disk etc. Unit tests are written and executed by developers.
Describe the behavior of the code corresponding to use cases cover technical corner cases what happens if null is passed if a test is not present for a corner case the behavior is undefined. The most common approach to unit testing requires drivers and stubs to be written. Most of the time a testing framework like junit or testng is used. But if you work in a team or if you re planning to launch a much larger project then it s good to build the habit of unit testing your code. Check across the date.
Test cases are typically written at a method level and executed via automation. It s far from obvious. To try it with out example above type in. Unit tests should test both sides of a given boundary. Not everyone has a need to write unit tests so these principles may not apply to smaller personal projects.
The go test tool has built in code coverage for statements. In roy osherove s the art of unit. How do you learn how to write good unit tests. The driver simulates a calling unit and the stub simulates the called unit.