Make type hints more strict

Author: Cito

mypy.ini

@@ -1,4 +1,11 @@
 [mypy]
 python_version = 3.9
-warn_redundant_casts = true
+check_untyped_defs = True
+no_implicit_optional = True
+strict_optional = True
+warn_redundant_casts = True
 warn_unused_ignores = True
+disallow_untyped_defs = True
+
+[mypy-tests.*]
+disallow_untyped_defs = False

src/graphql_relay/connection/array_connection.py

@@ -43,7 +43,7 @@ def __len__(self) -> int:
 
 def connection_from_array(
     data: SizedSliceable,
-    args: ConnectionArguments = None,
+    args: Optional[ConnectionArguments] = None,
     connection_type: ConnectionConstructor = Connection,
     edge_type: EdgeConstructor = Edge,
     page_info_type: PageInfoConstructor = PageInfo,
@@ -73,7 +73,7 @@ def connection_from_array(
 
 def connection_from_list(
     data: Sequence,
-    args: ConnectionArguments = None,
+    args: Optional[ConnectionArguments] = None,
     connection_type: ConnectionConstructor = Connection,
     edge_type: EdgeConstructor = Edge,
     pageinfo_type: PageInfoConstructor = PageInfo,
@@ -100,10 +100,10 @@ def connection_from_list(
 
 def connection_from_array_slice(
     array_slice: SizedSliceable,
-    args: ConnectionArguments = None,
+    args: Optional[ConnectionArguments] = None,
     slice_start: int = 0,
-    array_length: int = None,
-    array_slice_length: int = None,
+    array_length: Optional[int] = None,
+    array_slice_length: Optional[int] = None,
     connection_type: ConnectionConstructor = Connection,
     edge_type: EdgeConstructor = Edge,
     page_info_type: PageInfoConstructor = PageInfo,
@@ -181,13 +181,13 @@ def connection_from_array_slice(
 
 def connection_from_list_slice(
     list_slice: Sequence,
-    args: ConnectionArguments = None,
+    args: Optional[ConnectionArguments] = None,
     connection_type: ConnectionConstructor = Connection,
     edge_type: EdgeConstructor = Edge,
     pageinfo_type: PageInfoConstructor = PageInfo,
-    slice_start=0,
-    list_length=0,
-    list_slice_length=None,
+    slice_start: int = 0,
+    list_length: int = 0,
+    list_slice_length: Optional[int] = None,
 ) -> ConnectionType:
     """Deprecated alias for connection_from_array_slice.
 
@@ -256,7 +256,9 @@ def cursor_for_object_in_connection(
         return offset_to_cursor(offset)
 
 
-def get_offset_with_default(cursor: ConnectionCursor = None, default_offset=0) -> int:
+def get_offset_with_default(
+    cursor: Optional[ConnectionCursor] = None, default_offset: int = 0
+) -> int:
     """Get offset from a given cursor and a default.
 
     Given an optional cursor and a default offset, return the offset to use;

src/graphql_relay/connection/connection.py

@@ -1,6 +1,7 @@
-from typing import Any, Dict, List, NamedTuple, Optional
+from typing import Any, Dict, List, NamedTuple, Optional, Union
 
-from graphql.type import (
+from graphql import (
+    get_named_type,
     GraphQLArgument,
     GraphQLArgumentMap,
     GraphQLBoolean,
@@ -9,6 +10,7 @@
     GraphQLFieldResolver,
     GraphQLInt,
     GraphQLList,
+    GraphQLNamedOutputType,
     GraphQLNonNull,
     GraphQLObjectType,
     GraphQLString,
@@ -92,18 +94,18 @@ def resolve_maybe_thunk(thing_or_thunk: Thunk) -> Any:
 
 
 def connection_definitions(
-    node_type: GraphQLObjectType,
-    name: str = None,
-    resolve_node: GraphQLFieldResolver = None,
-    resolve_cursor: GraphQLFieldResolver = None,
-    edge_fields: Thunk[GraphQLFieldMap] = None,
-    connection_fields: Thunk[GraphQLFieldMap] = None,
+    node_type: Union[GraphQLNamedOutputType, GraphQLNonNull[GraphQLNamedOutputType]],
+    name: Optional[str] = None,
+    resolve_node: Optional[GraphQLFieldResolver] = None,
+    resolve_cursor: Optional[GraphQLFieldResolver] = None,
+    edge_fields: Optional[Thunk[GraphQLFieldMap]] = None,
+    connection_fields: Optional[Thunk[GraphQLFieldMap]] = None,
 ) -> GraphQLConnectionDefinitions:
     """Return GraphQLObjectTypes for a connection with the given name.
 
     The nodes of the returned object types will be of the specified type.
     """
-    name = name or node_type.name
+    name = name or get_named_type(node_type).name
     edge_fields = edge_fields or {}
     connection_fields = connection_fields or {}
 
@@ -203,12 +205,12 @@ class Edge(NamedTuple):
 
 class ConnectionType(Protocol):
     @property
-    def edges(self):
-        List[EdgeType]: ...
+    def edges(self) -> List[EdgeType]:
+        ...
 
     @property
-    def pageInfo(self):
-        PageInfoType: ...
+    def pageInfo(self) -> PageInfoType:
+        ...
 
 
 class ConnectionConstructor(Protocol):

src/graphql_relay/mutation/mutation.py

@@ -1,9 +1,8 @@
 from inspect import iscoroutinefunction
-from typing import Any, Callable
+from typing import Any, Callable, Dict, Optional
 
-from graphql.error import GraphQLError
-from graphql.pyutils import AwaitableOrValue, inspect
-from graphql.type import (
+from graphql import (
+    GraphQLError,
     GraphQLArgument,
     GraphQLField,
     GraphQLFieldMap,
@@ -16,7 +15,7 @@
     GraphQLString,
     Thunk,
 )
-
+from graphql.pyutils import AwaitableOrValue, inspect
 
 # Note: Contrary to the Javascript implementation of MutationFn,
 # the context is passed as part of the GraphQLResolveInfo and any arguments
@@ -32,7 +31,7 @@ def resolve_maybe_thunk(thing_or_thunk: Thunk) -> Any:
 
 
 class NullResult:
-    def __init__(self, clientMutationId=None):
+    def __init__(self, clientMutationId: Optional[str] = None) -> None:
         self.clientMutationId = clientMutationId
 
 
@@ -41,8 +40,9 @@ def mutation_with_client_mutation_id(
     input_fields: Thunk[GraphQLInputFieldMap],
     output_fields: Thunk[GraphQLFieldMap],
     mutate_and_get_payload: MutationFn,
-    description: str = None,
-    deprecation_reason: str = None,
+    description: Optional[str] = None,
+    deprecation_reason: Optional[str] = None,
+    extensions: Optional[Dict[str, Any]] = None,
 ) -> GraphQLField:
     """
     Returns a GraphQLFieldConfig for the specified mutation.
@@ -78,7 +78,7 @@ def augmented_output_fields() -> GraphQLFieldMap:
     if iscoroutinefunction(mutate_and_get_payload):
 
         # noinspection PyShadowingBuiltins
-        async def resolve(_root, info, input):
+        async def resolve(_root: Any, info: GraphQLResolveInfo, input: Dict) -> Any:
             payload = await mutate_and_get_payload(info, **input)
             try:
                 clientMutationId = input["clientMutationId"]
@@ -95,7 +95,10 @@ async def resolve(_root, info, input):
 
     else:
 
-        def resolve(_root, info, input):
+        # noinspection PyShadowingBuiltins
+        def resolve(  # type: ignore
+            _root: Any, info: GraphQLResolveInfo, input: Dict
+        ) -> Any:
             payload = mutate_and_get_payload(info, **input)
             try:
                 clientMutationId = input["clientMutationId"]
@@ -107,7 +110,7 @@ def resolve(_root, info, input):
             if payload is None:
                 payload = NullResult(clientMutationId)
             else:
-                payload.clientMutationId = clientMutationId
+                payload.clientMutationId = clientMutationId  # type: ignore
             return payload
 
     return GraphQLField(
@@ -116,4 +119,5 @@ def resolve(_root, info, input):
         deprecation_reason=deprecation_reason,
         args={"input": GraphQLArgument(GraphQLNonNull(input_type))},
         resolve=resolve,
+        extensions=extensions,
     )

src/graphql_relay/node/node.py

@@ -1,8 +1,8 @@
-from typing import Any, Callable, NamedTuple
+from typing import Any, Callable, NamedTuple, Optional
 
 from graphql_relay.utils.base64 import base64, unbase64
 
-from graphql.type import (
+from graphql import (
     GraphQLArgument,
     GraphQLNonNull,
     GraphQLID,
@@ -23,7 +23,7 @@ class GraphQLNodeDefinitions(NamedTuple):
 
 def node_definitions(
     id_fetcher: Callable[[str, GraphQLResolveInfo], Any],
-    type_resolver: GraphQLTypeResolver = None,
+    type_resolver: Optional[GraphQLTypeResolver] = None,
 ) -> GraphQLNodeDefinitions:
     """
     Given a function to map from an ID to an underlying object, and a function
@@ -96,7 +96,8 @@ def from_global_id(global_id: str) -> ResolvedGlobalId:
 
 
 def global_id_field(
-    type_name: str = None, id_fetcher: Callable[[Any, GraphQLResolveInfo], str] = None
+    type_name: Optional[str] = None,
+    id_fetcher: Optional[Callable[[Any, GraphQLResolveInfo], str]] = None,
 ) -> GraphQLField:
     """
     Creates the configuration for an id field on a node, using `to_global_id` to

src/graphql_relay/node/plural.py

@@ -1,6 +1,6 @@
-from typing import Any, Callable
+from typing import Any, Callable, List, Optional
 
-from graphql.type import (
+from graphql import (
     GraphQLArgument,
     GraphQLField,
     GraphQLInputType,
@@ -17,9 +17,9 @@ def plural_identifying_root_field(
     input_type: GraphQLInputType,
     output_type: GraphQLOutputType,
     resolve_single_input: Callable[[GraphQLResolveInfo, str], Any],
-    description: str = None,
+    description: Optional[str] = None,
 ) -> GraphQLField:
-    def resolve(_obj, info, **args):
+    def resolve(_obj: Any, info: GraphQLResolveInfo, **args: Any) -> List:
         inputs = args[arg_name]
         return [resolve_single_input(info, input_) for input_ in inputs]
 

src/graphql_relay/version.py

@@ -35,7 +35,7 @@ def from_str(cls, v: str) -> "VersionInfo":
         serial = int(serial) if serial else 0
         return cls(major, minor, micro, level, serial)
 
-    def __str__(self):
+    def __str__(self) -> str:
         v = f"{self.major}.{self.minor}.{self.micro}"
         level = self.releaselevel
         if level and level != "final":

tests/connection/test_array_connection.py

@@ -739,10 +739,10 @@ def uses_array_slice_length_instead_of_len_function():
             class LettersWithoutLen:
                 __getitem__ = letters.__getitem__
 
-            letters_without_len = LettersWithoutLen()
+            letters_without_len = cast(Sequence, LettersWithoutLen())
 
             with raises(TypeError):
-                len(cast(Sequence, letters_without_len))
+                len(letters_without_len)
 
             with raises(TypeError):
                 connection_from_array_slice(letters_without_len)

tests/connection/test_connection.py

@@ -5,6 +5,7 @@
     print_schema,
     GraphQLField,
     GraphQLInt,
+    GraphQLNonNull,
     GraphQLObjectType,
     GraphQLSchema,
     GraphQLString,
@@ -66,7 +67,7 @@ class User(NamedTuple):
 )
 
 friend_connection = connection_definitions(
-    user_type,
+    GraphQLNonNull(user_type),
     name="Friend",
     resolve_node=lambda edge, _info: all_users[edge.node],
     edge_fields=lambda: {
@@ -83,7 +84,7 @@ class User(NamedTuple):
 
 
 user_connection = connection_definitions(
-    user_type, resolve_node=lambda edge, _info: all_users[edge.node]
+    GraphQLNonNull(user_type), resolve_node=lambda edge, _info: all_users[edge.node]
 ).connection_type
 
 
@@ -245,7 +246,7 @@ def generates_correct_types():
             """An edge in a connection."""
             type FriendEdge {
               """The item at the end of the edge"""
-              node: User
+              node: User!
 
               """A cursor for use in pagination"""
               cursor: String!
@@ -264,7 +265,7 @@ def generates_correct_types():
             """An edge in a connection."""
             type UserEdge {
               """The item at the end of the edge"""
-              node: User
+              node: User!
 
               """A cursor for use in pagination"""
               cursor: String!

tests/node/test_global.py

@@ -2,8 +2,8 @@
 
 from pytest import fixture
 
-from graphql import graphql_sync
-from graphql.type import (
+from graphql import (
+    graphql_sync,
     GraphQLField,
     GraphQLList,
     GraphQLInt,