C# - How to mock or stub a class without an interface
Sometimes you come across a class that you need to stub or mock but it does not have an interface. The easiest way is of course »
xUnit - How to assert that a call throws an exception
A year ago I made a post on the absence of the DoesNotThrow assertion in xUnit. In this post I show how you can assert if »
The Arrange, Act and Assert structure for unit tests
The Triple A (AAA) abbreviation: Arrange. Act and Assert is a way to structure your unit tests into 3 sections: Arrange: Assign variables, setup stubs, mocks »
C# - how to inject, mock or stub DateTime for unit tests
In this post I will demonstrate how you can stub the DateTime struct in your unit tests. Most commonly the method DateTime.Now or DateTime.UtcNow »
xUnit - how to check if a call does not throw an exception
If you are moving from NUnit to xUnit, you will likely encounter the absence of the DoesNotThrow method in xUnit. At first I believed this did »
What is a unit test?
In this post I describe what units tests are all about. It seems to me that in the last many years, the focus has drifted away »
Deciding on what values to use for (unit) test cases
Often when writing tests one value can be as good as any other value. Such as if you need to apply a number within a range »
Levels of automated tests in software development and programming - when to use what?
In this post I will describe some automated testing techniques. Testing is done to assure quality in our systems. But what is quality? Quality is that »
Why do we use mocking for unit tests? and the use of test-doubles - Updated 2022
In order to understand how and why we use mocks for tests we need to understand different types of test doubles (implementations used for testing) and »