C# – How to unit test code that reads and writes to the console

When you’re unit testing code that uses the console IO methods, you’ll need a way to automate the input and a way to capture the output. There are two ways to do this: Redirect the console IO. Wrap the console IO method calls and mock out the wrapper. In this article, I’ll show how to … Read more

ASP.NET Core – How to unit test your middleware class

There are three requirements for unit testing a middleware class: Mock out RequestDelegate by defining a lambda that returns a Task (Task.FromException, Task.FromResult, or Task.FromCanceled). Mock out HttpContext by using DefaultHttpContext. The middleware function needs to be awaited, so your unit test needs to be defined with async Task. Here’s an example: This is a … Read more

C# – Use FluentAssertions to improve unit tests

FluentAssertions is a library that improves unit tests by providing better failure messages, simplifies assertions in many scenarios, and provides a fluent interface (which improves code readability). In this article, I’ll show a few examples of how FluentAssertions can improve unit tests by comparing it with the built-in assertions (from Microsoft.VisualStudio.TestTools.UnitTesting). Install FluentAssertions To get … Read more