It can be tricky with .NET Core to write tests to ensure that your Logger is working correctly because most mocking libraries are unable to override methods on Logger<T> such as LogCritical() because they are extension methods.
Attempting to override them with XUnit will give you an error similar to the following:
System.NotSupportedException: 'Unsupported expression: x => x.LogCritical("", new[] { })
Extension methods (here: LoggerExtensions.LogCritical) may not be used in setup / verification expressions.'
The aim of this project is to create a simple wrapper around the built-in dotnet Logger<T> that encapsulates the static extension methods into instance methods, allowing developers to mock, override and verify their usage in testing scenarios.
To use this in your project copy ILog.cs, Log.cs and ServiceCollectionExtensions.cs into your project and when registering your dependencies use the AddLogWrapper() extension method to register the ILog singleton.
Once this is done you can inject ILog<T> to any classes that require it and use it exactly as you would with ILogger<T>. You can even replace all instances of ILogger<T> with it.
This will then give you the ability to write unit tests that mock the ILog<T> dependency and enable you to override all the methods with your mocking library of choice.
See the sample project for an example of usage and some unit tests showing how it works.