Minor code simplifications (#146)

Author: yezz123

src/graphql/language/visitor.py

@@ -183,16 +183,15 @@ def __init_subclass__(cls) -> None:
                 kind: Optional[str] = None
             else:
                 attr, kind = attr_kind
-            if attr in ("enter", "leave"):
-                if kind:
-                    name = snake_to_camel(kind) + "Node"
-                    node_cls = getattr(ast, name, None)
-                    if (
-                        not node_cls
-                        or not isinstance(node_cls, type)
-                        or not issubclass(node_cls, Node)
-                    ):
-                        raise TypeError(f"Invalid AST node kind: {kind}.")
+            if attr in ("enter", "leave") and kind:
+                name = snake_to_camel(kind) + "Node"
+                node_cls = getattr(ast, name, None)
+                if (
+                    not node_cls
+                    or not isinstance(node_cls, type)
+                    or not issubclass(node_cls, Node)
+                ):
+                    raise TypeError(f"Invalid AST node kind: {kind}.")
 
     def get_visit_fn(self, kind: str, is_leaving: bool = False) -> Callable:
         """Get the visit function for the given node kind and direction."""
@@ -256,22 +255,18 @@ def visit(root: Node, visitor: Visitor) -> Any:
             node: Any = parent
             parent = ancestors_pop() if ancestors else None
             if is_edited:
-                if in_array:
-                    node = node[:]
-                else:
-                    node = copy(node)
+                node = node[:] if in_array else copy(node)
             edit_offset = 0
             for edit_key, edit_value in edits:
                 if in_array:
                     edit_key -= edit_offset
                 if in_array and (edit_value is REMOVE or edit_value is Ellipsis):
                     node.pop(edit_key)
                     edit_offset += 1
+                elif isinstance(node, list):
+                    node[edit_key] = edit_value
                 else:
-                    if isinstance(node, list):
-                        node[edit_key] = edit_value
-                    else:
-                        setattr(node, edit_key, edit_value)
+                    setattr(node, edit_key, edit_value)
 
             idx = stack.idx
             keys = stack.keys

src/graphql/pyutils/suggestion_list.py

@@ -73,7 +73,7 @@ def measure(self, option: str, threshold: int) -> Optional[int]:
             return None
 
         rows = self._rows
-        for j in range(0, b_len + 1):
+        for j in range(b_len + 1):
             rows[0][j] = j
 
         for i in range(1, a_len + 1):

src/graphql/subscription/map_async_iterator.py

@@ -33,8 +33,6 @@ async def __anext__(self) -> Any:
             if not isasyncgen(self.iterator):
                 raise StopAsyncIteration
             value = await self.iterator.__anext__()
-            result = self.callback(value)
-
         else:
             aclose = ensure_future(self._close_event.wait())
             anext = ensure_future(self.iterator.__anext__())
@@ -61,7 +59,8 @@ async def __anext__(self) -> Any:
                 raise error
 
             value = anext.result()
-            result = self.callback(value)
+
+        result = self.callback(value)
 
         return await result if isawaitable(result) else result
 
@@ -72,23 +71,24 @@ async def athrow(
         traceback: Optional[TracebackType] = None,
     ) -> None:
         """Throw an exception into the asynchronous iterator."""
-        if not self.is_closed:
-            athrow = getattr(self.iterator, "athrow", None)
-            if athrow:
-                await athrow(type_, value, traceback)
-            else:
-                await self.aclose()
-                if value is None:
-                    if traceback is None:
-                        raise type_
-                    value = (
-                        type_
-                        if isinstance(value, BaseException)
-                        else cast(Type[BaseException], type_)()
-                    )
-                if traceback is not None:
-                    value = value.with_traceback(traceback)
-                raise value
+        if self.is_closed:
+            return
+        athrow = getattr(self.iterator, "athrow", None)
+        if athrow:
+            await athrow(type_, value, traceback)
+        else:
+            await self.aclose()
+            if value is None:
+                if traceback is None:
+                    raise type_
+                value = (
+                    type_
+                    if isinstance(value, BaseException)
+                    else cast(Type[BaseException], type_)()
+                )
+            if traceback is not None:
+                value = value.with_traceback(traceback)
+            raise value
 
     async def aclose(self) -> None:
         """Close the iterator."""

src/graphql/utilities/print_schema.py

@@ -108,10 +108,7 @@ def is_schema_of_common_names(schema: GraphQLSchema) -> bool:
         return False
 
     subscription_type = schema.subscription_type
-    if subscription_type and subscription_type.name != "Subscription":
-        return False
-
-    return True
+    return not subscription_type or subscription_type.name == "Subscription"
 
 
 def print_type(type_: GraphQLNamedType) -> str:

src/graphql/utilities/strip_ignored_characters.py

@@ -79,9 +79,10 @@ def strip_ignored_characters(source: Union[str, Source]) -> str:
         # Also prevent case of non-punctuator token following by spread resulting
         # in invalid token (e.g.`1...` is invalid Float token).
         is_non_punctuator = not is_punctuator_token_kind(current_token.kind)
-        if was_last_added_token_non_punctuator:
-            if is_non_punctuator or current_token.kind == TokenKind.SPREAD:
-                stripped_body += " "
+        if was_last_added_token_non_punctuator and (
+            is_non_punctuator or current_token.kind == TokenKind.SPREAD
+        ):
+            stripped_body += " "
 
         token_body = body[current_token.start : current_token.end]
         if token_kind == TokenKind.BLOCK_STRING:

src/graphql/validation/rules/lone_anonymous_operation.py

@@ -20,9 +20,8 @@ def __init__(self, context: ASTValidationContext):
 
     def enter_document(self, node: DocumentNode, *_args: Any) -> None:
         self.operation_count = sum(
-            1
+            isinstance(definition, OperationDefinitionNode)
             for definition in node.definitions
-            if isinstance(definition, OperationDefinitionNode)
         )
 
     def enter_operation_definition(

src/graphql/validation/rules/single_field_subscriptions.py

@@ -23,62 +23,63 @@ class SingleFieldSubscriptionsRule(ValidationRule):
     def enter_operation_definition(
         self, node: OperationDefinitionNode, *_args: Any
     ) -> None:
-        if node.operation == OperationType.SUBSCRIPTION:
-            schema = self.context.schema
-            subscription_type = schema.subscription_type
-            if subscription_type:
-                operation_name = node.name.value if node.name else None
-                variable_values: Dict[str, Any] = {}
-                document = self.context.document
-                fragments: Dict[str, FragmentDefinitionNode] = {
-                    definition.name.value: definition
-                    for definition in document.definitions
-                    if isinstance(definition, FragmentDefinitionNode)
-                }
-                fields = collect_fields(
-                    schema,
-                    fragments,
-                    variable_values,
-                    subscription_type,
-                    node.selection_set,
-                    {},
-                    set(),
-                )
-                if len(fields) > 1:
-                    field_selection_lists = list(fields.values())
-                    extra_field_selection_lists = field_selection_lists[1:]
-                    extra_field_selection = [
-                        field
-                        for fields in extra_field_selection_lists
-                        for field in (
-                            fields
-                            if isinstance(fields, list)
-                            else [cast(FieldNode, fields)]
+        if node.operation != OperationType.SUBSCRIPTION:
+            return
+        schema = self.context.schema
+        subscription_type = schema.subscription_type
+        if subscription_type:
+            operation_name = node.name.value if node.name else None
+            variable_values: Dict[str, Any] = {}
+            document = self.context.document
+            fragments: Dict[str, FragmentDefinitionNode] = {
+                definition.name.value: definition
+                for definition in document.definitions
+                if isinstance(definition, FragmentDefinitionNode)
+            }
+            fields = collect_fields(
+                schema,
+                fragments,
+                variable_values,
+                subscription_type,
+                node.selection_set,
+                {},
+                set(),
+            )
+            if len(fields) > 1:
+                field_selection_lists = list(fields.values())
+                extra_field_selection_lists = field_selection_lists[1:]
+                extra_field_selection = [
+                    field
+                    for fields in extra_field_selection_lists
+                    for field in (
+                        fields
+                        if isinstance(fields, list)
+                        else [cast(FieldNode, fields)]
+                    )
+                ]
+                self.report_error(
+                    GraphQLError(
+                        (
+                            "Anonymous Subscription"
+                            if operation_name is None
+                            else f"Subscription '{operation_name}'"
                         )
-                    ]
+                        + " must select only one top level field.",
+                        extra_field_selection,
+                    )
+                )
+            for field_nodes in fields.values():
+                field = field_nodes[0]
+                field_name = field.name.value
+                if field_name.startswith("__"):
                     self.report_error(
                         GraphQLError(
                             (
                                 "Anonymous Subscription"
                                 if operation_name is None
                                 else f"Subscription '{operation_name}'"
                             )
-                            + " must select only one top level field.",
-                            extra_field_selection,
+                            + " must not select an introspection top level field.",
+                            field_nodes,
                         )
                     )
-                for field_nodes in fields.values():
-                    field = field_nodes[0]
-                    field_name = field.name.value
-                    if field_name.startswith("__"):
-                        self.report_error(
-                            GraphQLError(
-                                (
-                                    "Anonymous Subscription"
-                                    if operation_name is None
-                                    else f"Subscription '{operation_name}'"
-                                )
-                                + " must not select an introspection top level field.",
-                                field_nodes,
-                            )
-                        )

src/graphql/validation/validation_context.py

@@ -97,10 +97,12 @@ def report_error(self, error: GraphQLError) -> None:
     def get_fragment(self, name: str) -> Optional[FragmentDefinitionNode]:
         fragments = self._fragments
         if fragments is None:
-            fragments = {}
-            for statement in self.document.definitions:
-                if isinstance(statement, FragmentDefinitionNode):
-                    fragments[statement.name.value] = statement
+            fragments = {
+                statement.name.value: statement
+                for statement in self.document.definitions
+                if isinstance(statement, FragmentDefinitionNode)
+            }
+
             self._fragments = fragments
         return fragments.get(name)