fluentvalidation error message contains c# property name and not client side json property name?

Question

I have a C# WebApi project and i am using FluentValidation.WebApi package for validation of client inputs.

Below is my model class code which has C# property named "IsPremium". This same property has json name "isLuxury" for all the clients.

[Serializable, JsonObject, Validator(typeof(ProductValidator))]
public class Product
{
    [JsonProperty("isLuxury")]
    public bool? IsPremium { get; set; }
}

And my validator class looks like:

public class ProductValidator : AbstractValidator<Product>
    {
        public ProductValidator()
        {
            RuleFor(product => product.isPremium).NotNull();
        }
    }

So for a request like: http://localhost:52664/api/product

Request body:{ "isLuxury": "" }

I get following error:

{
  "Message": "The request is invalid.",
  "ModelState": {
    "product.isPremium": [
      "'is Premium' must not be empty."
    ]
  }
}

Fluent here is picking C# property name which makes no sense to the client as it knows it as "isLuxury". How can i force fluent to pick names from json property and not from c# property to give better validations like "'isLuxury' must not be empty."?

If not possible, i will have to rename all my C# properties to have same name as these json exposed to all the clients. Please suggest if you have any other better way to solve this problem.

Answer 1

Modify the validator class with the OverridePropertyName method

public class ProductValidator : AbstractValidator<Product>
    {
        public ProductValidator()
        {
            RuleFor(product => product.isPremium).NotNull().OverridePropertyName("isLuxury");
        }
    }

Referring: https://github.com/JeremySkinner/FluentValidation/wiki/d.-Configuring-a-Validator#overriding-the-default-property-name

Alternatively you can call the WithName method which does a similar thing. If you want to completely rename the property, I'd use the OverridePropertyName method.