Graphene: Escaped JSONStrings as mutation arguments cause GraphQLSyntaxError

[btubbs]

It seems like this should work:

import graphene
from graphene.types.json import JSONString


class CreatePerson(graphene.Mutation):
    class Input:
        name = graphene.String()
        data = JSONString()

    ok = graphene.Boolean()
    person = graphene.Field(lambda: Person)

    @staticmethod
    def mutate(root, args, context, info):
        person = Person(name=args.get('name'), data=args.get('data'))
        ok = True
        return CreatePerson(person=person, ok=ok)

class Person(graphene.ObjectType):
    name = graphene.String()
    age = graphene.Int()
    data = JSONString()

class MyMutations(graphene.ObjectType):
    create_person = CreatePerson.Field()

# We must define a query for our schema
class Query(graphene.ObjectType):
    person = graphene.Field(Person)

schema = graphene.Schema(query=Query, mutation=MyMutations)
res = schema.execute("""
mutation myFirstMutation {
     createPerson(name:"Peter", data: "{\"foo\":\"bar\"}") {
        person {
            name,
            data
        }
        ok
    }
}""")

print(res.errors)
print(res.data)

But it gives this error:

[GraphQLSyntaxError('Syntax Error GraphQL request (3:45) Expected :, found String ":"\n\n2: mutation myFirstMutation {\n3:      createPerson(name:"Peter", data: "{"foo":"bar"}") {\n                                               ^\n4:         person {\n',)]

If I change the argument to an empty JSON object (ie "{}"), then I don't get the error anymore.

Judging by issue #223, this worked as of July 2016.

[btubbs]

I've found that this works if I use double backslashes to escape the quotes in the mutation argument. Working example:

import graphene
from pprint import pprint

class CreatePerson(graphene.Mutation):
    class Arguments:
        name = graphene.String()
        meta = graphene.JSONString()

    ok = graphene.Boolean()
    person = graphene.Field(lambda: Person)

    def mutate(self, info, name, meta):
        pprint(meta)
        person = Person(name=name, meta=meta)
        ok = True

        return CreatePerson(person=person, ok=ok)

class Person(graphene.ObjectType):
    name = graphene.String()
    meta = graphene.JSONString()

class MyMutations(graphene.ObjectType):
    create_person = CreatePerson.Field()

# We must define a query for our schema
class Query(graphene.ObjectType):
    person = graphene.Field(Person)

schema = graphene.Schema(query=Query, mutation=MyMutations)

q = """
mutation myFirstMutation {
createPerson(name:"Peter", meta:"{\\"foo\\":\\"bar\\"}") {
        person {
            name,
            meta
        }
        ok
    }
}
"""

result = schema.execute(q)
print(result)
print(result.errors)

import json
print(json.dumps(result.data, indent=2))