public void Test1() { var integrationTestMockBuilder = MockBuilder.IntegrationTest <ITestIntegrationApp, TestIntegrationApp>( new Installer(), config => config.WithTestDependenciesToMock(TestDependency.Of <IExternalSupplierClass>())); var mockDataFromSupplier = "Mock data from supplier"; integrationTestMockBuilder.AddMockActionOf <IExternalSupplierClass>(mock => mock.Setup(x => x.GetDataFromUnreliableSupplier()).Returns(() => mockDataFromSupplier)); var expectedResult = "Logged a message" + mockDataFromSupplier + "Data from DB" + "Other data from DB"; var result = integrationTestMockBuilder.GetTestedService().DoStuffWithServices(); result.Should().Be(expectedResult); }