Radarr/src/NzbDrone.Api/Validation/EmptyCollectionValidator.cs

using System.Collections.Generic;
using FluentValidation.Validators;
using NzbDrone.Common.Extensions;

namespace NzbDrone.Api.Validation
{
    public class EmptyCollectionValidator<T> : PropertyValidator
    {
        public EmptyCollectionValidator()
            : base("Collection Must Be Empty")
        {
        }

        protected override bool IsValid(PropertyValidatorContext context)
        {
            if (context.PropertyValue == null) return true;

            var collection = context.PropertyValue as IEnumerable<T>;

            return collection != null && collection.Empty();
        }
    }
}