add-validation-rules.md

title	summary	tags
Add Validation Rules	Add GraphQL validation rules.	validation,security

AddValidationRules

This extension allows you add custom validation rules.

See graphql.validation.rules.custom for some custom rules that can be added from GraphQl-core.

Usage example:

import strawberry
from strawberry.extensions import AddValidationRules
from graphql import ValidationRule


@strawberry.type
class Query:
    @strawberry.field
    def hello(self) -> str:
        return "Hello, world!"


class MyCustomRule(ValidationRule): ...


schema = strawberry.Schema(
    Query,
    extensions=[
        AddValidationRules(MyCustomRule),
    ],
)

API reference:

class AddValidationRules(validation_rules): ...

validation_rules: List[Type[ASTValidationRule]]

List of GraphQL validation rules.

More examples:

Adding a custom rule

import strawberry
from strawberry.extensions import AddValidationRules
from graphql import ValidationRule


@strawberry.type
class Query:
    @strawberry.field
    def hello(self) -> str:
        return "Hello, world!"


class CustomRule(ValidationRule):
    def enter_field(self, node, *args) -> None:
        if node.name.value == "example":
            self.report_error(GraphQLError("Can't query field 'example'"))


schema = strawberry.Schema(
    Query,
    extensions=[
        AddValidationRules([CustomRule]),
    ],
)

result = schema.execute_sync("{ example }")

assert str(result.errors[0]) == "Can't query field 'example'"

Adding the `NoDeprecatedCustomRule` from GraphQL-core

import strawberry
from strawberry.extensions import AddValidationRules
from graphql.validation import NoDeprecatedCustomRule


@strawberry.type
class Query:
    @strawberry.field
    def hello(self) -> str:
        return "Hello, world!"


schema = strawberry.Schema(
    Query,
    extensions=[
        AddValidationRules([NoDeprecatedCustomRule]),
    ],
)

Adding the `NoSchemaIntrospectionCustomRule` from GraphQL-core

import strawberry
from strawberry.extensions import AddValidationRules
from graphql.validation import NoSchemaIntrospectionCustomRule


@strawberry.type
class Query:
    @strawberry.field
    def hello(self) -> str:
        return "Hello, world!"


schema = strawberry.Schema(
    Query,
    extensions=[
        AddValidationRules([NoSchemaIntrospectionCustomRule]),
    ],
)