Sonarr/src/NzbDrone.Core/Validation/FolderValidator.cs

using FluentValidation.Validators;
using NzbDrone.Common;

namespace NzbDrone.Core.Validation
{
    public class FolderValidator : PropertyValidator
    {
        public FolderValidator()
            : base("Invalid Path")
        {
        }

        protected override bool IsValid(PropertyValidatorContext context)
        {
            if (context.PropertyValue == null) return false;
            return context.PropertyValue.ToString().IsPathValid();
        }
    }
}