5 Best Practices to Follow to Improve your Unit Testing
Unit testing, sometimes called isolation testing, is one aspect of the broader software testing process. Unit tests are a way to ensure that code behaves in the way that you expect it to. They do this by running assertions on small units of code — hence the name “unit” tests. Each unit test focuses on exercising a single piece of behavior within a program. If that behavior breaks down in some way, for example if there’s a bug or if something goes wrong, its corresponding unit test should throw an error or fail.
1. Write readable tests
- Tests should be easy to read, understand and maintain. You don’t want other developers to have a hard time understanding your code, so take the time to make your tests as clear as possible.
- Keep it simple and focused on what you’re trying to test: avoid unnecessary details that don’t benefit anyone but yourself.
2. Avoid magic numbers and magic strings
- Don’t hard-code the name of your test or class, method, variable etc.
- Use discriminators to distinguish between different types (e.g., Account2 and Account3).
- Do not use hard-coded values in your tests e.g., $account->amount=9000; instead you should use mocks/stubs for this purpose
3. Avoid test interdependencies
- Don’t test the same thing more than once. You should avoid writing duplicate tests. Duplicate tests should be removed.
- Don’t test multiple things in the same test. If you’re testing two things, write two separate tests instead of putting them into one big test file.
- Don’t test the same thing in multiple places. This is a huge source of duplication and violation of DRY principle (Don’t Repeat Yourself). If something needs to be tested similarly across multiple classes or modules, then it might make sense to create an abstract class with common functionality and then inherit from this class for each module/class that will use this functionality and add additional logic on top of that provided by abstract class — you don’t have to worry about repeating yourself too much because all your derived classes are using similar code base from abstract class! And if at some point you need modifications done on those derived classes then just modify them accordingly; no one said it’s easy but there’s always an elegant solution if we keep our eyes open :)
4. Avoid logic in tests
Your tests should only be responsible for verifying that the code does what it is meant to do. Logic should be used in the production code, not in your unit test suite. The reason for this is that logic makes your tests harder to understand, write and maintain. As a result, logic in tests often has unintended consequences which may not become obvious until later on when you try to change something or add more functionality.
Logic within a test will also make it difficult for someone else who might need access to your test suite because they have no idea how everything works together or where the original idea came from when they see what looks like random data being passed into methods etc… This can slow them down while they try figure out why something isn’t working properly before they even get started!
5. Refrain multiple asserts in a single unit test
When we write unit tests, we often use asserts to validate the state of an object. This is perfectly fine, but if you want to improve your unit testing practices, you should refrain from using multiple asserts in a single unit test.
The reason for doing so is simple: it increases code complexity and makes it harder to read and understand the test’s intention.
Conclusion
There are many things you can do to improve your unit testing. Writing good tests is as important as writing good code, and we hope by following these tips you will achieve success in both areas. We also recommend reading our other articles on this topic such as How To Be Successful With Unit Testing For Beginners or Learning About The Best Practices When It Comes Time For Writing Tests.