Combining Autofac and Microsoft DI in unit tests

I had to write a test where I need to inject a configuration dependency through IOptions<>.  So far I had been using Autofac in my tests, so I wouldn’t go through all the trouble to get IOptions<> working inside Autofac (especially when Microsoft DI offers the convenient AddOptions<> and Configure<> methods).

Luckily it is not that hard to bring the 2 DI containers together. Here is the code I used inside my tests:

	var configuration = new ConfigurationBuilder()
	.AddJsonFile("appsettings.json", optional: true)
	.Build();
	//Initialize Microsoft DI
	var serviceCollection = new ServiceCollection();
	serviceCollection.AddOptions();
	serviceCollection.Configure<ExampleOptions>(configuration.GetSection("Example"));
	//Initialize Autofac
	var containerBuilder = new ContainerBuilder();
	//Link the 2 together
	containerBuilder.Populate(serviceCollection);
	var container = containerBuilder.Build();

view raw AddOptions.cs hosted with ❤ by GitHub