Default resolver does not work for Enums

If no explicit resolver is given, graphene nicely resolves fields by trying to access the attribute of the same name on the current node. This does not work for Enum’s though, as illustrated by the following example:

import graphene


class SomeEnum(graphene.Enum):
    Bar = 0
    Baz = 1


class Query(graphene.ObjectType):

    foo = graphene.Field(SomeEnum)
    biz = graphene.Field(graphene.String)


class SomeObject:
    def __init__(self):
        self.foo = SomeEnum.Bar
        self.biz = 'foobar'


if __name__ == '__main__':
    obj = SomeObject()
    schema = graphene.Schema(Query)
    query = '{foo,biz}'
    result = schema.execute(query, root_value=obj)
    print(result.data['foo'])
    print(result.data['biz'])

This should print

Bar
foobar

is does however print

None
foobar

I would have expected this to either returnenum.value or raise an exception, instead of silently returning None.

The obvious solution is to add a custom resolver, of course:

class Query(graphene.ObjectType):
    foo = graphene.Field(SomeEnum)
    biz = graphene.Field(graphene.String)
    
    def resolve_foo(root, *args, **kwargs):
        return root.foo.value

I’d think we should either remove the implicit default-resolver altogether, or take care that all graphql-types are handled properly.

[lincolnq]

I also have this problem, and it’s a big blocker for me. However, I don’t like the suggested PR. I think it would be better to fix it at the GraphQLEnumType level (because this is really not an issue with the resolver – it’s an issue with the enum type itself not recognizing instances of enum as valid values), but I’m not sure how exactly is the best way to do it.

Example that clarifies that it’s not a resolver issue:

import graphene as gql

class Currency(gql.Enum):
    USD = 10
    GBP = 20

class Query(gql.ObjectType):
    currency1 = Currency()
    currency2 = Currency()
    def resolve_currency1(self, info):
        """Return a Currency value."""
        return 10
    def resolve_currency2(self, info):
        """Return a Currency instance."""
        return Currency.USD

schema = gql.Schema(query=Query)
assert schema.execute('{currency1}').data['currency1'] == 'USD' # works
assert schema.execute('{currency2}').data['currency2'] == 'USD' # fails, it's None

[ProjectCheshire]

Resolving per above and lack of further activity.