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XUnit
• NuGet Dependencies
• Microsoft.NET.Test.SDK
• Xunit
• Xunit.runner.visualstudio
• Note: You can shoose a Xunit Project in VS, which already contains all
dependencies
• Keywords
• [Fact] as test method attribute
• Assert.*](https://image.slidesharecdn.com/automatedtesting-200715184313/85/Automated-testing-of-ASP-Net-Core-applications-6-320.jpg)
Automated testing of ASP .Net Core applications
- 1. 1 Automated Testing Part 1 – Unit Testing Noah Ispas | Data One GmbH
- 2. 2 » • Why? • Levels • Unit Testing • What is a unit? • Scope • Naming • Anatomy • Tight vs Loose Coupling • Real World Scenario & Mocking • Takeaways Agenda
- 3. 3 „Developer testing is an important step towards accountability. It gives developers a way to demonstrate the quality of the software they produce.“ Kent Beck
- 4. 4 Why? • Prove that software works • Regression • Trust the code • Test cases are specifications • Refactoring • Reduce manual testing • Easier to locate errors Why even write automated tests?
- 5. 5 Levels
- 6. 6 XUnit • NuGet Dependencies • Microsoft.NET.Test.SDK • Xunit • Xunit.runner.visualstudio • Note: You can shoose a Xunit Project in VS, which already contains all dependencies • Keywords • [Fact] as test method attribute • Assert.*
- 7. 7 What is a Unit ? • A Function/Method • A Collection of Functions/Methods • A Whole Class • -> The smaller the better • -> The more isolated the more better
- 9. 9 Scope/Test Cases & Naming
- 10. 10 Anatomy of a Test Case • Arange • Act • Assert • Cleanup
- 11. 11 Anatomy of a Test Case
- 12. 12 That was a perfect world example … … how about the reality?
- 14. 14 • Loose coupling and Separation of Concerns are very important design principles • What‘s the problem with tight coupling? • Changing something without having to touch other places becomes hard • Automated testing becomes hard • What is the benefit of loose coupling? • Better understandability • Better maintainability • Decreased risk when changing something • Decreased cost of change! Tight coupling is bad
- 15. 15 Compare those
- 16. 16 Compare those • What if we want to extend SomeService and decide that SomeController needs to use that extension? • -> We have to also change SomeController in order to use the extension
- 17. 17 Compare those • Now we can simply inject the extension. • -> Inversion of Control Principle (SomeService could be an abstraction) • -> Dependency Injection
- 18. 18 Unit Under Test • What is the testing scope? • -> We just want to test the controller • -> All dependencies should be mocked
- 19. 19 Moq • NuGet Dependencies • Moq • Usage • var mock = new Mock<ClassToBeMocked>(); • mock.Setup(mockedClass => mockedClass.method()).Returns(true) • Placeholder for Parameters: It.IsAny<String>() • A Mock is like a decorator for a class object. Reference the object with Mock.Object
- 20. 20 • A unit usually refers to a function/method or a whole class • Arrange, Act, Assert • Test the functionality isolated and mock every downstream dependency • Don‘t be tricked by test coverage reports • Line coverage does only mean that those lines are called in a unit test • But lines can be called with the test assertion beeing shitty • High Line Coverage does not mean that the actual Test Coverage is good • Branch Coverage is a better metric, as it says something about which branches are called in unit tests • Still the test cases have to make sense • Don‘t test the code of 3rd party frameworks • Design Principles help a lot • Separation of Concerns • Open Closed Principle -> Inversion of Control • Dependency Injection • Loose Coupling Unit testing – Takeways
- 21. 21 Fragen? »
- 22. 22 • Play around with unit testing, those basics should be enough for adding solid amount of unit tests -> build a routine (tasks are not done until there are no unit tests) • Even more advanced, real life scenarios (maybe using some code of existing applications) -> how to handle refactoring and unit testing at the same time?! • More precise mocking examples • Pitfalls • Integration Testing • Deep Dive in Design Principles?! What‘s Next
- 23. 23 • https://github.com/moq/moq4 • https://xunit.net/ • https://docs.microsoft.com/en-us/visualstudio/test/unit-test-basics?view=vs- 2019 • https://stackify.com/unit-testing-basics-best-practices/ • https://medium.com/better-programming/unit-testing-best-practices- 9bceeafe6edf Further Reading