public void Configure_Configure_ReturnNext()
        {
            var validateOptionsWithFluentValidationStartupFilter =
                new ValidateOptionsWithFluentValidationStartupFilter(Array.Empty <IValidateOptionsWithFluentValidationOnStartup>());

            Action <IApplicationBuilder> next = _ => { };

            validateOptionsWithFluentValidationStartupFilter.Configure(next).Should().BeSameAs(next);
        }
        public void Configure_Configure_ValidateAll()
        {
            var validateOptionsWithFluentValidationOnStartupMock1 = new ValidateOptionsWithFluentValidationOnStartup();
            var validateOptionsWithFluentValidationOnStartupMock2 = new ValidateOptionsWithFluentValidationOnStartup();

            var startupValidators = new[]
            {
                validateOptionsWithFluentValidationOnStartupMock1,
                validateOptionsWithFluentValidationOnStartupMock2,
            };

            var validateOptionsWithFluentValidationStartupFilter = new ValidateOptionsWithFluentValidationStartupFilter(startupValidators);

            Action <IApplicationBuilder> next = _ => { };

            validateOptionsWithFluentValidationStartupFilter.Configure(next);

            validateOptionsWithFluentValidationOnStartupMock1.Counter.Should().Be(1);
            validateOptionsWithFluentValidationOnStartupMock2.Counter.Should().Be(1);
        }