use explicit optional type on arguments with default None value

Signed-off-by: Oleg Höfling <[email protected]>

src/graphql/graphql.py

@@ -1,6 +1,6 @@
 from asyncio import ensure_future
 from inspect import isawaitable
-from typing import Any, Awaitable, Dict, Union, Type, cast
+from typing import Any, Awaitable, Dict, Optional, Union, Type, cast
 
 from .error import GraphQLError
 from .execution import execute, ExecutionResult, ExecutionContext, Middleware
@@ -21,11 +21,11 @@ async def graphql(
     source: Union[str, Source],
     root_value: Any = None,
     context_value: Any = None,
-    variable_values: Dict[str, Any] = None,
-    operation_name: str = None,
-    field_resolver: GraphQLFieldResolver = None,
-    type_resolver: GraphQLTypeResolver = None,
-    middleware: Middleware = None,
+    variable_values: Optional[Dict[str, Any]] = None,
+    operation_name: Optional[str] = None,
+    field_resolver: Optional[GraphQLFieldResolver] = None,
+    type_resolver: Optional[GraphQLTypeResolver] = None,
+    middleware: Optional[Middleware] = None,
     execution_context_class: Type[ExecutionContext] = ExecutionContext,
 ) -> ExecutionResult:
     """Execute a GraphQL operation asynchronously.
@@ -95,11 +95,11 @@ def graphql_sync(
     source: Union[str, Source],
     root_value: Any = None,
     context_value: Any = None,
-    variable_values: Dict[str, Any] = None,
-    operation_name: str = None,
-    field_resolver: GraphQLFieldResolver = None,
-    type_resolver: GraphQLTypeResolver = None,
-    middleware: Middleware = None,
+    variable_values: Optional[Dict[str, Any]] = None,
+    operation_name: Optional[str] = None,
+    field_resolver: Optional[GraphQLFieldResolver] = None,
+    type_resolver: Optional[GraphQLTypeResolver] = None,
+    middleware: Optional[Middleware] = None,
     execution_context_class: Type[ExecutionContext] = ExecutionContext,
 ) -> ExecutionResult:
     """Execute a GraphQL operation synchronously.

src/graphql/subscription/subscribe.py

@@ -1,5 +1,14 @@
 from inspect import isawaitable
-from typing import Any, AsyncIterable, AsyncIterator, Awaitable, Dict, Union, cast
+from typing import (
+    Any,
+    AsyncIterable,
+    AsyncIterator,
+    Awaitable,
+    Dict,
+    Optional,
+    Union,
+    cast,
+)
 
 from ..error import GraphQLError, located_error
 from ..execution.execute import (
@@ -23,10 +32,10 @@ async def subscribe(
     document: DocumentNode,
     root_value: Any = None,
     context_value: Any = None,
-    variable_values: Dict[str, Any] = None,
-    operation_name: str = None,
-    field_resolver: GraphQLFieldResolver = None,
-    subscribe_field_resolver: GraphQLFieldResolver = None,
+    variable_values: Optional[Dict[str, Any]] = None,
+    operation_name: Optional[str] = None,
+    field_resolver: Optional[GraphQLFieldResolver] = None,
+    subscribe_field_resolver: Optional[GraphQLFieldResolver] = None,
 ) -> Union[AsyncIterator[ExecutionResult], ExecutionResult]:
     """Create a GraphQL subscription.
 
@@ -91,9 +100,9 @@ async def create_source_event_stream(
     document: DocumentNode,
     root_value: Any = None,
     context_value: Any = None,
-    variable_values: Dict[str, Any] = None,
-    operation_name: str = None,
-    field_resolver: GraphQLFieldResolver = None,
+    variable_values: Optional[Dict[str, Any]] = None,
+    operation_name: Optional[str] = None,
+    field_resolver: Optional[GraphQLFieldResolver] = None,
 ) -> Union[AsyncIterable[Any], ExecutionResult]:
     """Create source even stream
 

src/graphql/validation/validate.py

@@ -1,4 +1,4 @@
-from typing import Collection, List
+from typing import Collection, List, Optional
 
 from ..error import GraphQLError
 from ..language import DocumentNode, ParallelVisitor, visit
@@ -19,9 +19,9 @@ class ValidationAbortedError(RuntimeError):
 def validate(
     schema: GraphQLSchema,
     document_ast: DocumentNode,
-    rules: Collection[RuleType] = None,
-    type_info: TypeInfo = None,
-    max_errors: int = None,
+    rules: Optional[Collection[RuleType]] = None,
+    type_info: Optional[TypeInfo] = None,
+    max_errors: Optional[int] = None,
 ) -> List[GraphQLError]:
     """Implements the "Validation" section of the spec.
 
@@ -82,8 +82,8 @@ def on_error(error: GraphQLError) -> None:
 
 def validate_sdl(
     document_ast: DocumentNode,
-    schema_to_extend: GraphQLSchema = None,
-    rules: Collection[RuleType] = None,
+    schema_to_extend: Optional[GraphQLSchema] = None,
+    rules: Optional[Collection[RuleType]] = None,
 ) -> List[GraphQLError]:
     """Validate an SDL document.