How to Unit Test Startup.cs in .NET Core

Question

How do people go about Unit Testing their Startup.cs classes in a .NET Core 2 application? All of the functionality seems to be provided by Static extensions methods which a

Answer 1

This approach works, and uses the real MVC pipeline, as things should only be mocked if you need to change how they work.

public void AddTransactionLoggingCreatesConnection()
{
     var servCollection = new ServiceCollection();

    //Add any injection stuff you need here
    //servCollection.AddSingleton(logger.Object);

    //Setup the MVC builder thats needed
    IMvcBuilder mvcBuilder = new MvcBuilder(servCollection, new Microsoft.AspNetCore.Mvc.ApplicationParts.ApplicationPartManager());

    IEnumerable> confValues = new List>()
    {
        new KeyValuePair("TransactionLogging:Enabled", "True"),
        new KeyValuePair("TransactionLogging:Uri", "https://api.something.com/"),
        new KeyValuePair("TransactionLogging:Version", "1"),
        new KeyValuePair("TransactionLogging:Queue:Enabled", "True")
    };

    ConfigurationBuilder builder = new ConfigurationBuilder();
    builder.AddInMemoryCollection(confValues);

    var confRoot = builder.Build();
    StartupExtensions.YourExtensionMethod(mvcBuilder); // Any other params
}