FluentValidation.Tests.ConditionTests - Grouping Validation Conditions

FluentValidation.Tests.ConditionTests.cs

       private class GroupedWhenConditionValidator : ExpressiveValidator<Person>
        {
            public GroupedWhenConditionValidator()
            {
                When(x => x.Id != 0)
                    .Check(RuleFor(x => x.Age).GreaterThan(4))
                    .Check(RuleFor(x => x.Discount).Equal(10m));
            }
        }

        [Test]
        public void Grouped_condition_can_ignore_mutiple_rules_when_predicate_fails()
        {
			var validator = new GroupedWhenConditionValidator();
			var result = validator.Validate(new Person());
			result.Errors.Count.ShouldEqual(0);
        }

        [Test]
        public void Grouped_condition_can_apply_to_mutiple_rules_when_predicate_passes()
        {
			var validator = new GroupedWhenConditionValidator();
            var result = validator.Validate(new Person() { Id = 1001 });
			result.Errors.Count.ShouldEqual(2);
        }

        public class ExpressiveValidator<T> : AbstractValidator<T>
        {
            public GroupedConditionValidator<T> When(Func<T, bool> predicate)
            {
                return new GroupedConditionValidator<T>().When(predicate);
            }

            public GroupedConditionValidator<T> Unless(Func<T, bool> predicate)
            {
                return new GroupedConditionValidator<T>().Unless(predicate);
            }
        }

        public class GroupedConditionValidator<T> 
        {
            Func<T, bool> whenPredicate;
            Func<T, bool> unlessPredicate;

            public GroupedConditionValidator()
            {
                whenPredicate = x => true;
                unlessPredicate = x => false;
            }

            public GroupedConditionValidator<T> When(Func<T, bool> predicate)
            {
                this.whenPredicate = predicate;

                return this;
            }

            public GroupedConditionValidator<T> Unless(Func<T, bool> predicate)
            {
                this.unlessPredicate = predicate;

                return this;
            }

            public GroupedConditionValidator<T> Check<TProperty>(IRuleBuilderOptions<T, TProperty> builderOptions)
            {
                builderOptions.When(whenPredicate).Unless(unlessPredicate);

                return this;
            }
        }