C# – How to unit test code that uses HttpClient

HttpClient is a dependency. Like any other dependency, you need to pass it into your code (aka dependency injection). By passing it in, you can mock it out in unit tests. There are two approaches to mocking it out: Wrap the HttpClient and mock out the wrapper. Use a real HttpClient with a mocked out … Read more C# – How to unit test code that uses HttpClient

Moq – How to return different values each time a mocked method is called

When you’re mocking a method that’s called multiple times, you may want to change the behavior of the method each time it’s called. The way you do this with Moq is by using SetupSequence(), like this: Note: You can also make it throw an exception in the sequence. Example of code I want to test … Read more Moq – How to return different values each time a mocked method is called

C# – How to unit test async methods

Let’s say you have the following async method you want to test: Here’s how to unit test this: This is awaiting the method you’re testing. To await it, you must make the unit test method return async Task. This example is a bit simplistic. In the real world when you are working with async methods, … Read more C# – How to unit test async methods

How to mock static methods

The need to mock static methods in order to add a unit test is a very common problem. It’s often the case that these static methods are in third-party libraries. There are many utility libraries that are completely made up of static methods. While this makes them very easy to use, it makes them really … Read more How to mock static methods