How to mock parameter provided as input to anonymous Func delegate via lambda expression?-CodePudding

I have this code for which I'm trying to write a unit test:

public static void AddRuntimeServices(this IServiceCollection services)
{
    services.AddScoped<IAppClient>((serviceProvider) =>
    {
        var snapshotService = serviceProvider.GetRequiredService<ISnapshotService>();
        var urlContext = serviceProvider.GetRequiredService<IUrlContext>();

        return new AppClient(
            serviceUrl: urlContext.restApiUrl,
            httpClient: snapshotService.Client);
    });
}

In this code, I can mock the services input given to this method, but how do I mock the serviceProvider variable (that comes from within the services input given to this method), that's given as an input into an anonymous Func delegate that's being written inline ?

I want to be able to mock serviceProvider, so that I can write something like this:

serviceProvider.GetRequiredService<ISnapshotService>().Returns(somethingToReturn);

I'm using MSTest (Microsoft.VisualStudio.TestTools.UnitTesting) to write my unit tests.

CodePudding user response：

Use an actual service collection. and add the mocked services so that when it resolves them you have control of the desired behavior

//...

//Arrange

IServiceCollection services = new ServiceCollection();

ISnapshotService snapshotService = Mock.Of<ISnapshotService>();
IUrlContext urlContext = Mock.Of<IUrlContext>();

services.AddScoped<ISnapshotService>(sp => snapshotService);
services.AddScoped<IUrlContext>(sp => urlContext);

//Act
services.AddRuntimeServices();

IServiceProvider serviceProvider = services.BuildServiceProvider();
IAppClient client = serviceProvider.GetRequiredService<IAppClient>();

//Assert
//...assert expected behavior

//...