Moq IServiceProvider / IServiceScope

Question

I am trying to create a Mock (using Moq) for an IServiceProvider so that I can test my repository class:

public class ApiResourceRepository : IApiRe         


        

Answer 1

I was also looking for this, but i only needed to mock GetService. I always use AutoFac to auto generate mocks. In this example 'GetService' always returns a mocked instance. You can change the mock behavior afterwards with the freeze method.

Example:

Class to test:

public class ApiResourceRepository : ApiResourceRepository {
            private readonly IServiceProvider _serviceProvider;

            public ApiResourceRepository(IServiceProvider serviceProvider) {
                _serviceProvider = serviceProvider;
            }

            public object Get(int id) {
                using (var serviceScope = _serviceProvider.CreateScope()) {
                    var repo = serviceScope.ServiceProvider.GetService();
                    return repo.GetById(id);
                }
            }
        }

Unit Test:

 [Fact]
        public void Test() {
            // arrange
            var fixture = new Fixture()
             .Customize(new AutoMoqCustomization())
             .Customize(new ServiceProviderCustomization());

            fixture.Freeze>()
                .Setup(m => m.GetById(It.IsAny()))
                .Returns(new Person(Name = "John"));

            // Act
            var apiResource = _fixture.Create();
            var person = apiResource.Get(1);

            // Assert
            ...
        }

Custom AutoFac provider

public class ServiceProviderCustomization : ICustomization {

        public void Customize(IFixture fixture) {
            var serviceProviderMock = fixture.Freeze>();

            // GetService
            serviceProviderMock
               .Setup(m => m.GetService(It.IsAny()))
               .Returns((Type type) => {
                   var mockType = typeof(Mock<>).MakeGenericType(type);
                   var mock = fixture.Create(mockType, new SpecimenContext(fixture)) as Mock;

                   // Inject mock again, so the behavior can be changed with _fixture.Freeze()
                   MethodInfo method = typeof(FixtureRegistrar).GetMethod("Inject");
                   MethodInfo genericMethod = method.MakeGenericMethod(mockType);
                   genericMethod.Invoke(null, new object[] { fixture, mock });

                   return mock.Object;
               });

            // Scoped
            var serviceScopeMock = fixture.Freeze>();
            serviceProviderMock
               .As()
               .Setup(m => m.CreateScope())
               .Returns(serviceScopeMock.Object);

            serviceProviderMock.As()
                .Setup(m => m.GetRequiredService(typeof(IServiceScopeFactory)))
                .Returns(serviceProviderMock.Object);
        }
    }