cost_validator raises GraphQLError when used to validate query without required variables being provided

[pigletto]

Problem description

If the query with variables is used when cost_validator is enabled validation fails with the following error:

GraphQLError("Argument 'id' of required type 'Int!' was provided the variable '$id' which was not provided a runtime value.\n\nGraphQL request:1:34\n1 | query Hello($id: Int!){ hello(id:$id) }\n | ^")]

Version

Ariadne 0.13.0

How to reproduce:

from ariadne.validation import cost_validator
from graphql.language import parse
from graphql.validation import validate

type_defs = gql(
    """
    type Query {
        hello(id:Int!): String!
    }
""")

if __name__ == "__main__":
    schema = make_executable_schema(type_defs)
    document = parse('query Hello($id: Int!){ hello(id:$id) }')
    validation_errors = validate(schema, document, [cost_validator(maximum_cost=5)])
    print('errors', validation_errors)

I can make it work by disabling cost_validator or by explicitly setting variables to cost_validator constructor (like below) but this doesn't seem to make any sense for bigger schemas:

validation_errors = validate(schema, document, [cost_validator(maximum_cost=5, variables={'id': 10})])

[rafalp]

Cost validator requires that query is executable. This means you can't define variables in query but don't provide them to validator, as such query is not executable.

You will have to setup cost validator dynamically for your code to work:

def get_validation_rules(context_value, document, data):
    return [cost_validator(maximum_cost=5, variables=data.get("variables"))]

[pigletto]

Thanks, this works. I've created PR to have this information in the docs.