public void Given_rule_is_configured_via_factory_and_serviceCollection_it_should_add_instance_to_rule_collection() { var configuredRule = new TestValidationRule(); IComponentContext providedComponentContext = null; IIbanNetOptionsBuilder returnedBuilder = _builder .WithRule(ctx => { providedComponentContext = ctx; return(configuredRule); }); // Act IContainer container = _containerBuilder.Build(); // Assert IbanValidatorOptions opts = container.Resolve <IbanValidatorOptions>(); opts.Should() .HaveRule <IIbanValidationRule>() .And.HaveCount(1) .And.Subject.Single() .Should() .BeSameAs(configuredRule); providedComponentContext.Should().NotBeNull(); returnedBuilder.Should().BeSameAs(_builder); }