Validator not validating range attribute on properties

I have a submit model with a property of type decimal that represents a percentage. I use the range attribute to only allow values from 0 to 100. I have a unit test where I use the Validator to test this validation on the submit model. However, when I pass in an input that’s outside the valid range, the validation result does not have any errors.

    public class SubmitModel
    {
        [Range(0d, 100d)]
        public decimal Percentage { get; set; }
    }

The sample submit model

    [TestFixture]
    public class SubmitModelTests
    {
        [Test]
        public void InvalidInputs_Should_Have_ValidationErrors([Values(-0.01, 100.01)] decimal percentage)
        {
            var submitModel = new SubmitModel
            {
                Percentage = percentage
            };
            var validationContext = new ValidationContext(submitModel);
            var validationResults = new List<ValidationResult>();

            Validator.TryValidateObject(submitModel, validationContext, validationResults);
            validationResults.Count.Should().Be(1);
        }
    }

The unit test should give 1 error but the test fails as there is no error.

For the Validator to validate the properties, you need to tell it so. The Validator has an overload method TryValidateObject with an additional flag validateAllProperties. Set this to true and it will validate the properties and pass the test.