Fields' names are snake_case in SerializerMutation errors

When serializer is not valid, SerializerMutation returns errors where fields’ names are snake_case (default DRF behaviour). I believe that it’s easier for the client to use pascalCase which is used for the input of mutation.

Simplified example:

• serializers.py

  from rest_framework import serializers
  
  class UserSerializer(serializers.ModelSerializer):
      class Meta:
          model = User
          fields = ('birth_date', )
  
      def validate_birth_date(self, value):
          age = calculate_age(value)
          if int(age) < 18:
              raise serializers.ValidationError(
                  'Sorry, you must be at least 18 years old.'
              )
          return value
  

• schema.py

  from graphene_django.rest_framework.mutation import SerializerMutation
  
  class UserMutation(SerializerMutation):
      class Meta:
          serializer_class = UserSerializer
  

• GraphQL mutation

  mutation CreateUser {
    signUp(input: {birthDate: "2010-01-01"}) {
      birthDate
      errors {
        field
        messages
      }
    }
  }
  

• Response with birth_date in errors (instead of birthDate)

  {
    "data": {
      "signUp": {
        "birthDate": null,
        "errors": [
          {
            "field": "birth_date",
            "messages": [
              "Sorry, you must be at least 18 years old."
            ]
          }
        ]
      }
    }
  }
  

[jkimbo]

This issue should be fixed in v2.4.0 by setting the CAMELCASE_ERRORS setting: http://docs.graphene-python.org/projects/django/en/latest/settings/#camelcase-errors

[jkimbo]

@kamilkijak will this PR fix your issue: https://github.com/graphql-python/graphene-django/pull/514 ?