Graph.ArgumentValidator 1.0.0

Adds support for validating input arguments in HotChocolate

Generally, we use attributes from System.ComponentModel.DataAnnotations for validating our input models in controllers.

As HotChocolate doesn't validate input arguments, After installing this package, By just adding 2 lines of code in your Startup.cs file. You will be adding support for validation to all input models in your Queries/Mutations.

Tech Note: You can use all validation attributes/rules from System.ComponentModel.DataAnnotations (ex: Required, MinLength, Regex etc). This package just adds a middleware to the hot chocolate resolver for validating your input models as configured in below steps.

Steps for configuring validator

Step 1

Go to StartUp.cs file and inside ConfigureServices make the following changes.

Step 2

Keep this code to validate all inputs of GraphQL Query/Mutation.

ValidatorSettings.ValidateAllInputs = true;

Step 3

Add argument validator to services by referring to below code

services
  .AddGraphQLServer()
  .AddArgumentValidator();

Additional Configuration

If you don't want to validate all inputs then you can skip step 2 and follow the optional step i.e

Just add the Validatable attribute to the class u defined for input.

Ex:

    using System.ComponentModel.DataAnnotations;
    using Graph.ArgumentValidator;
    
    namespace Demo
    {
        [Validatable]
        public class AddUserInput
        {
            [Required, MinLength(4, ErrorMessage = "Username must be atleast 4 characters.")]
            public string UserName { get; set; }

            [Required, RegularExpression(@"^[^@\s]+@[^@\s]+\.[^@\s]+$", ErrorMessage = "Email Id format is invalid")]
            public string Email { get; set; }

            [Required, RegularExpression(@"^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$", ErrorMessage = "Password needs to be more strong.")]
            public string Password { get; set; }
        }
    }

When the user is given wrong values to input, this is how the response from GraphQL Server will look like

{
  "errors": [
    {
      "message": "Username must be at least 4 characters."
    },
    {
      "message": "Password needs to be more strong."
    }
  ]
}