from asyncio import ensure_future, gather from collections.abc import Mapping from inspect import isawaitable from typing import ( Any, AsyncIterable, Awaitable, Callable, Dict, Iterable, List, Optional, Tuple, Type, Union, cast, ) try: from typing import TypedDict except ImportError: # Python < 3.8 from typing_extensions import TypedDict from ..error import GraphQLError, GraphQLFormattedError, located_error from ..language import ( DocumentNode, FieldNode, FragmentDefinitionNode, OperationDefinitionNode, OperationType, ) from ..pyutils import ( AwaitableOrValue, Path, Undefined, inspect, is_iterable, ) from ..pyutils import ( is_awaitable as default_is_awaitable, ) from ..type import ( GraphQLAbstractType, GraphQLField, GraphQLFieldResolver, GraphQLLeafType, GraphQLList, GraphQLNonNull, GraphQLObjectType, GraphQLOutputType, GraphQLResolveInfo, GraphQLSchema, GraphQLTypeResolver, SchemaMetaFieldDef, TypeMetaFieldDef, TypeNameMetaFieldDef, assert_valid_schema, is_abstract_type, is_leaf_type, is_list_type, is_non_null_type, is_object_type, ) from .collect_fields import collect_fields, collect_sub_fields from .middleware import MiddlewareManager from .values import get_argument_values, get_variable_values __all__ = [ "assert_valid_execution_arguments", "default_field_resolver", "default_type_resolver", "execute", "execute_sync", "get_field_def", "ExecutionResult", "ExecutionContext", "FormattedExecutionResult", "Middleware", ] # Terminology # # "Definitions" are the generic name for top-level statements in the document. # Examples of this include: # 1) Operations (such as a query) # 2) Fragments # # "Operations" are a generic name for requests in the document. # Examples of this include: # 1) query, # 2) mutation # # "Selections" are the definitions that can appear legally and at # single level of the query. These include: # 1) field references e.g "a" # 2) fragment "spreads" e.g. "...c" # 3) inline fragment "spreads" e.g. "...on Type { a }" class FormattedExecutionResult(TypedDict, total=False): """Formatted execution result""" errors: List[GraphQLFormattedError] data: Optional[Dict[str, Any]] extensions: Dict[str, Any] class ExecutionResult: """The result of GraphQL execution. - ``data`` is the result of a successful execution of the query. - ``errors`` is included when any errors occurred as a non-empty list. - ``extensions`` is reserved for adding non-standard properties. """ __slots__ = "data", "errors", "extensions" data: Optional[Dict[str, Any]] errors: Optional[List[GraphQLError]] extensions: Optional[Dict[str, Any]] def __init__( self, data: Optional[Dict[str, Any]] = None, errors: Optional[List[GraphQLError]] = None, extensions: Optional[Dict[str, Any]] = None, ): self.data = data self.errors = errors self.extensions = extensions def __repr__(self) -> str: name = self.__class__.__name__ ext = "" if self.extensions is None else f", extensions={self.extensions}" return f"{name}(data={self.data!r}, errors={self.errors!r}{ext})" def __iter__(self) -> Iterable[Any]: return iter((self.data, self.errors)) @property def formatted(self) -> FormattedExecutionResult: """Get execution result formatted according to the specification.""" formatted: FormattedExecutionResult = {"data": self.data} if self.errors is not None: formatted["errors"] = [error.formatted for error in self.errors] if self.extensions is not None: formatted["extensions"] = self.extensions return formatted def __eq__(self, other: Any) -> bool: if isinstance(other, dict): if "extensions" not in other: return other == dict(data=self.data, errors=self.errors) return other == dict( data=self.data, errors=self.errors, extensions=self.extensions ) if isinstance(other, tuple): if len(other) == 2: return other == (self.data, self.errors) return other == (self.data, self.errors, self.extensions) return ( isinstance(other, self.__class__) and other.data == self.data and other.errors == self.errors and other.extensions == self.extensions ) def __ne__(self, other: Any) -> bool: return not self == other Middleware = Optional[Union[Tuple, List, MiddlewareManager]] class ExecutionContext: """Data that must be available at all points during query execution. Namely, schema of the type system that is currently executing, and the fragments defined in the query document. """ schema: GraphQLSchema fragments: Dict[str, FragmentDefinitionNode] root_value: Any context_value: Any operation: OperationDefinitionNode variable_values: Dict[str, Any] field_resolver: GraphQLFieldResolver type_resolver: GraphQLTypeResolver subscribe_field_resolver: GraphQLFieldResolver errors: List[GraphQLError] middleware_manager: Optional[MiddlewareManager] is_awaitable = staticmethod(default_is_awaitable) def __init__( self, schema: GraphQLSchema, fragments: Dict[str, FragmentDefinitionNode], root_value: Any, context_value: Any, operation: OperationDefinitionNode, variable_values: Dict[str, Any], field_resolver: GraphQLFieldResolver, type_resolver: GraphQLTypeResolver, subscribe_field_resolver: GraphQLFieldResolver, errors: List[GraphQLError], middleware_manager: Optional[MiddlewareManager], is_awaitable: Optional[Callable[[Any], bool]], ) -> None: self.schema = schema self.fragments = fragments self.root_value = root_value self.context_value = context_value self.operation = operation self.variable_values = variable_values self.field_resolver = field_resolver self.type_resolver = type_resolver self.subscribe_field_resolver = subscribe_field_resolver self.errors = errors self.middleware_manager = middleware_manager if is_awaitable: self.is_awaitable = is_awaitable # type: ignore self._subfields_cache: Dict[Tuple, Dict[str, List[FieldNode]]] = {} @classmethod def build( cls, schema: GraphQLSchema, document: DocumentNode, root_value: Any = None, context_value: Any = None, raw_variable_values: Optional[Dict[str, Any]] = None, operation_name: Optional[str] = None, field_resolver: Optional[GraphQLFieldResolver] = None, type_resolver: Optional[GraphQLTypeResolver] = None, subscribe_field_resolver: Optional[GraphQLFieldResolver] = None, middleware: Optional[Middleware] = None, is_awaitable: Optional[Callable[[Any], bool]] = None, ) -> Union[List[GraphQLError], "ExecutionContext"]: """Build an execution context Constructs a ExecutionContext object from the arguments passed to execute, which we will pass throughout the other execution methods. Throws a GraphQLError if a valid execution context cannot be created. For internal use only. """ operation: Optional[OperationDefinitionNode] = None fragments: Dict[str, FragmentDefinitionNode] = {} middleware_manager: Optional[MiddlewareManager] = None if middleware is not None: if isinstance(middleware, (list, tuple)): middleware_manager = MiddlewareManager(*middleware) elif isinstance(middleware, MiddlewareManager): middleware_manager = middleware else: raise TypeError( "Middleware must be passed as a list or tuple of functions" " or objects, or as a single MiddlewareManager object." f" Got {inspect(middleware)} instead." ) for definition in document.definitions: if isinstance(definition, OperationDefinitionNode): if operation_name is None: if operation: return [ GraphQLError( "Must provide operation name" " if query contains multiple operations." ) ] operation = definition elif definition.name and definition.name.value == operation_name: operation = definition elif isinstance(definition, FragmentDefinitionNode): fragments[definition.name.value] = definition if not operation: if operation_name is not None: return [GraphQLError(f"Unknown operation named '{operation_name}'.")] return [GraphQLError("Must provide an operation.")] coerced_variable_values = get_variable_values( schema, operation.variable_definitions or (), raw_variable_values or {}, max_errors=50, ) if isinstance(coerced_variable_values, list): return coerced_variable_values # errors return cls( schema, fragments, root_value, context_value, operation, coerced_variable_values, # coerced values field_resolver or default_field_resolver, type_resolver or default_type_resolver, subscribe_field_resolver or default_field_resolver, [], middleware_manager, is_awaitable, ) @staticmethod def build_response( data: Optional[Dict[str, Any]], errors: List[GraphQLError] ) -> ExecutionResult: """Build response. Given a completed execution context and data, build the (data, errors) response defined by the "Response" section of the GraphQL spec. """ if not errors: return ExecutionResult(data, None) # Sort the error list in order to make it deterministic, since we might have # been using parallel execution. errors.sort( key=lambda error: (error.locations or [], error.path or [], error.message) ) return ExecutionResult(data, errors) def execute_operation( self, operation: OperationDefinitionNode, root_value: Any ) -> Optional[AwaitableOrValue[Any]]: """Execute an operation. Implements the "Executing operations" section of the spec. """ root_type = self.schema.get_root_type(operation.operation) if root_type is None: raise GraphQLError( "Schema is not configured to execute" f" {operation.operation.value} operation.", operation, ) root_fields = collect_fields( self.schema, self.fragments, self.variable_values, root_type, operation.selection_set, ) path = None return ( self.execute_fields_serially if operation.operation == OperationType.MUTATION else self.execute_fields )(root_type, root_value, path, root_fields) def execute_fields_serially( self, parent_type: GraphQLObjectType, source_value: Any, path: Optional[Path], fields: Dict[str, List[FieldNode]], ) -> AwaitableOrValue[Dict[str, Any]]: """Execute the given fields serially. Implements the "Executing selection sets" section of the spec for fields that must be executed serially. """ results: AwaitableOrValue[Dict[str, Any]] = {} is_awaitable = self.is_awaitable for response_name, field_nodes in fields.items(): field_path = Path(path, response_name, parent_type.name) result = self.execute_field( parent_type, source_value, field_nodes, field_path ) if result is Undefined: continue if is_awaitable(results): # noinspection PyShadowingNames async def await_and_set_result( results: Awaitable[Dict[str, Any]], response_name: str, result: AwaitableOrValue[Any], ) -> Dict[str, Any]: awaited_results = await results awaited_results[response_name] = ( await result if is_awaitable(result) else result ) return awaited_results results = await_and_set_result( cast(Awaitable, results), response_name, result ) elif is_awaitable(result): # noinspection PyShadowingNames async def set_result( results: Dict[str, Any], response_name: str, result: Awaitable, ) -> Dict[str, Any]: results[response_name] = await result return results results = set_result( cast(Dict[str, Any], results), response_name, result ) else: cast(Dict[str, Any], results)[response_name] = result return results def execute_fields( self, parent_type: GraphQLObjectType, source_value: Any, path: Optional[Path], fields: Dict[str, List[FieldNode]], ) -> AwaitableOrValue[Dict[str, Any]]: """Execute the given fields concurrently. Implements the "Executing selection sets" section of the spec for fields that may be executed in parallel. """ results = {} is_awaitable = self.is_awaitable awaitable_fields: List[str] = [] append_awaitable = awaitable_fields.append for response_name, field_nodes in fields.items(): field_path = Path(path, response_name, parent_type.name) result = self.execute_field( parent_type, source_value, field_nodes, field_path ) if result is not Undefined: results[response_name] = result if is_awaitable(result): append_awaitable(response_name) # If there are no coroutines, we can just return the object if not awaitable_fields: return results # Otherwise, results is a map from field name to the result of resolving that # field, which is possibly a coroutine object. Return a coroutine object that # will yield this same map, but with any coroutines awaited in parallel and # replaced with the values they yielded. async def get_results() -> Dict[str, Any]: results.update( zip( awaitable_fields, await gather(*(results[field] for field in awaitable_fields)), ) ) return results return get_results() def build_resolve_info( self, field_def: GraphQLField, field_nodes: List[FieldNode], parent_type: GraphQLObjectType, path: Path, ) -> GraphQLResolveInfo: """Build the GraphQLResolveInfo object. For internal use only.""" # The resolve function's first argument is a collection of information about # the current execution state. return GraphQLResolveInfo( field_nodes[0].name.value, field_nodes, field_def.type, parent_type, path, self.schema, self.fragments, self.root_value, self.operation, self.variable_values, self.context_value, self.is_awaitable, ) def execute_field( self, parent_type: GraphQLObjectType, source: Any, field_nodes: List[FieldNode], path: Path, ) -> AwaitableOrValue[Any]: """Resolve the field on the given source object. Implements the "Executing fields" section of the spec. In particular, this method figures out the value that the field returns by calling its resolve function, then calls complete_value to await coroutine objects, serialize scalars, or execute the sub-selection-set for objects. """ field_def = get_field_def(self.schema, parent_type, field_nodes[0]) if not field_def: return Undefined return_type = field_def.type resolve_fn = field_def.resolve or self.field_resolver if self.middleware_manager: resolve_fn = self.middleware_manager.get_field_resolver(resolve_fn) info = self.build_resolve_info(field_def, field_nodes, parent_type, path) # Get the resolve function, regardless of if its result is normal or abrupt # (error). try: # Build a dictionary of arguments from the field.arguments AST, using the # variables scope to fulfill any variable references. args = get_argument_values(field_def, field_nodes[0], self.variable_values) # Note that contrary to the JavaScript implementation, we pass the context # value as part of the resolve info. result = resolve_fn(source, info, **args) if self.is_awaitable(result): # noinspection PyShadowingNames async def await_result() -> Any: try: completed = self.complete_value( return_type, field_nodes, info, path, await result ) if self.is_awaitable(completed): return await completed return completed except Exception as raw_error: error = located_error(raw_error, field_nodes, path.as_list()) self.handle_field_error(error, return_type) return None return await_result() completed = self.complete_value( return_type, field_nodes, info, path, result ) if self.is_awaitable(completed): # noinspection PyShadowingNames async def await_completed() -> Any: try: return await completed except Exception as raw_error: error = located_error(raw_error, field_nodes, path.as_list()) self.handle_field_error(error, return_type) return None return await_completed() return completed except Exception as raw_error: error = located_error(raw_error, field_nodes, path.as_list()) self.handle_field_error(error, return_type) return None def handle_field_error( self, error: GraphQLError, return_type: GraphQLOutputType, ) -> None: # If the field type is non-nullable, then it is resolved without any protection # from errors, however it still properly locates the error. if is_non_null_type(return_type): raise error # Otherwise, error protection is applied, logging the error and resolving a # null value for this field if one is encountered. self.errors.append(error) return None def complete_value( self, return_type: GraphQLOutputType, field_nodes: List[FieldNode], info: GraphQLResolveInfo, path: Path, result: Any, ) -> AwaitableOrValue[Any]: """Complete a value. Implements the instructions for completeValue as defined in the "Value completion" section of the spec. If the field type is Non-Null, then this recursively completes the value for the inner type. It throws a field error if that completion returns null, as per the "Nullability" section of the spec. If the field type is a List, then this recursively completes the value for the inner type on each item in the list. If the field type is a Scalar or Enum, ensures the completed value is a legal value of the type by calling the ``serialize`` method of GraphQL type definition. If the field is an abstract type, determine the runtime type of the value and then complete based on that type. Otherwise, the field type expects a sub-selection set, and will complete the value by evaluating all sub-selections. """ # If result is an Exception, throw a located error. if isinstance(result, Exception): raise result # If field type is NonNull, complete for inner type, and throw field error if # result is null. if is_non_null_type(return_type): completed = self.complete_value( cast(GraphQLNonNull, return_type).of_type, field_nodes, info, path, result, ) if completed is None: raise TypeError( "Cannot return null for non-nullable field" f" {info.parent_type.name}.{info.field_name}." ) return completed # If result value is null or undefined then return null. if result is None or result is Undefined: return None # If field type is List, complete each item in the list with inner type if is_list_type(return_type): return self.complete_list_value( cast(GraphQLList, return_type), field_nodes, info, path, result ) # If field type is a leaf type, Scalar or Enum, serialize to a valid value, # returning null if serialization is not possible. if is_leaf_type(return_type): return self.complete_leaf_value(cast(GraphQLLeafType, return_type), result) # If field type is an abstract type, Interface or Union, determine the runtime # Object type and complete for that type. if is_abstract_type(return_type): return self.complete_abstract_value( cast(GraphQLAbstractType, return_type), field_nodes, info, path, result ) # If field type is Object, execute and complete all sub-selections. if is_object_type(return_type): return self.complete_object_value( cast(GraphQLObjectType, return_type), field_nodes, info, path, result ) # Not reachable. All possible output types have been considered. raise TypeError( # pragma: no cover "Cannot complete value of unexpected output type:" f" '{inspect(return_type)}'." ) def complete_list_value( self, return_type: GraphQLList[GraphQLOutputType], field_nodes: List[FieldNode], info: GraphQLResolveInfo, path: Path, result: Union[AsyncIterable[Any], Iterable[Any]], ) -> AwaitableOrValue[List[Any]]: """Complete a list value. Complete a list value by completing each item in the list with the inner type. """ if not is_iterable(result): # experimental: allow async iterables if isinstance(result, AsyncIterable): # noinspection PyShadowingNames async def async_iterable_to_list( async_result: AsyncIterable[Any], ) -> Any: sync_result = [item async for item in async_result] return self.complete_list_value( return_type, field_nodes, info, path, sync_result ) return async_iterable_to_list(result) raise GraphQLError( "Expected Iterable, but did not find one for field" f" '{info.parent_type.name}.{info.field_name}'." ) result = cast(Iterable[Any], result) # This is specified as a simple map, however we're optimizing the path where # the list contains no coroutine objects by avoiding creating another coroutine # object. item_type = return_type.of_type is_awaitable = self.is_awaitable awaitable_indices: List[int] = [] append_awaitable = awaitable_indices.append completed_results: List[Any] = [] append_result = completed_results.append for index, item in enumerate(result): # No need to modify the info object containing the path, since from here on # it is not ever accessed by resolver functions. item_path = path.add_key(index, None) completed_item: AwaitableOrValue[Any] if is_awaitable(item): # noinspection PyShadowingNames async def await_completed(item: Any, item_path: Path) -> Any: try: completed = self.complete_value( item_type, field_nodes, info, item_path, await item ) if is_awaitable(completed): return await completed return completed except Exception as raw_error: error = located_error( raw_error, field_nodes, item_path.as_list() ) self.handle_field_error(error, item_type) return None completed_item = await_completed(item, item_path) else: try: completed_item = self.complete_value( item_type, field_nodes, info, item_path, item ) if is_awaitable(completed_item): # noinspection PyShadowingNames async def await_completed(item: Any, item_path: Path) -> Any: try: return await item except Exception as raw_error: error = located_error( raw_error, field_nodes, item_path.as_list() ) self.handle_field_error(error, item_type) return None completed_item = await_completed(completed_item, item_path) except Exception as raw_error: error = located_error(raw_error, field_nodes, item_path.as_list()) self.handle_field_error(error, item_type) completed_item = None if is_awaitable(completed_item): append_awaitable(index) append_result(completed_item) if not awaitable_indices: return completed_results # noinspection PyShadowingNames async def get_completed_results() -> List[Any]: for index, result in zip( awaitable_indices, await gather( *(completed_results[index] for index in awaitable_indices) ), ): completed_results[index] = result return completed_results return get_completed_results() @staticmethod def complete_leaf_value(return_type: GraphQLLeafType, result: Any) -> Any: """Complete a leaf value. Complete a Scalar or Enum by serializing to a valid value, returning null if serialization is not possible. """ serialized_result = return_type.serialize(result) if serialized_result is Undefined or serialized_result is None: raise TypeError( f"Expected `{inspect(return_type)}.serialize({inspect(result)})`" f" to return non-nullable value, returned: {inspect(serialized_result)}" ) return serialized_result def complete_abstract_value( self, return_type: GraphQLAbstractType, field_nodes: List[FieldNode], info: GraphQLResolveInfo, path: Path, result: Any, ) -> AwaitableOrValue[Any]: """Complete an abstract value. Complete a value of an abstract type by determining the runtime object type of that value, then complete the value for that type. """ resolve_type_fn = return_type.resolve_type or self.type_resolver runtime_type = resolve_type_fn(result, info, return_type) if self.is_awaitable(runtime_type): runtime_type = cast(Awaitable, runtime_type) async def await_complete_object_value() -> Any: value = self.complete_object_value( self.ensure_valid_runtime_type( await runtime_type, # type: ignore return_type, field_nodes, info, result, ), field_nodes, info, path, result, ) if self.is_awaitable(value): return await value # type: ignore return value # pragma: no cover return await_complete_object_value() runtime_type = cast(Optional[str], runtime_type) return self.complete_object_value( self.ensure_valid_runtime_type( runtime_type, return_type, field_nodes, info, result ), field_nodes, info, path, result, ) def ensure_valid_runtime_type( self, runtime_type_name: Any, return_type: GraphQLAbstractType, field_nodes: List[FieldNode], info: GraphQLResolveInfo, result: Any, ) -> GraphQLObjectType: if runtime_type_name is None: raise GraphQLError( f"Abstract type '{return_type.name}' must resolve" " to an Object type at runtime" f" for field '{info.parent_type.name}.{info.field_name}'." f" Either the '{return_type.name}' type should provide" " a 'resolve_type' function or each possible type should provide" " an 'is_type_of' function.", field_nodes, ) if is_object_type(runtime_type_name): # pragma: no cover raise GraphQLError( "Support for returning GraphQLObjectType from resolve_type was" " removed in GraphQL-core 3.2, please return type name instead." ) if not isinstance(runtime_type_name, str): raise GraphQLError( f"Abstract type '{return_type.name}' must resolve" " to an Object type at runtime" f" for field '{info.parent_type.name}.{info.field_name}' with value" f" {inspect(result)}, received '{inspect(runtime_type_name)}'.", field_nodes, ) runtime_type = self.schema.get_type(runtime_type_name) if runtime_type is None: raise GraphQLError( f"Abstract type '{return_type.name}' was resolved to a type" f" '{runtime_type_name}' that does not exist inside the schema.", field_nodes, ) if not is_object_type(runtime_type): raise GraphQLError( f"Abstract type '{return_type.name}' was resolved" f" to a non-object type '{runtime_type_name}'.", field_nodes, ) runtime_type = cast(GraphQLObjectType, runtime_type) if not self.schema.is_sub_type(return_type, runtime_type): raise GraphQLError( f"Runtime Object type '{runtime_type.name}' is not a possible" f" type for '{return_type.name}'.", field_nodes, ) return runtime_type def complete_object_value( self, return_type: GraphQLObjectType, field_nodes: List[FieldNode], info: GraphQLResolveInfo, path: Path, result: Any, ) -> AwaitableOrValue[Dict[str, Any]]: """Complete an Object value by executing all sub-selections.""" # Collect sub-fields to execute to complete this value. sub_field_nodes = self.collect_subfields(return_type, field_nodes) # If there is an `is_type_of()` predicate function, call it with the current # result. If `is_type_of()` returns False, then raise an error rather than # continuing execution. if return_type.is_type_of: is_type_of = return_type.is_type_of(result, info) if self.is_awaitable(is_type_of): async def execute_subfields_async() -> Dict[str, Any]: if not await is_type_of: # type: ignore raise invalid_return_type_error( return_type, result, field_nodes ) return self.execute_fields( return_type, result, path, sub_field_nodes ) # type: ignore return execute_subfields_async() if not is_type_of: raise invalid_return_type_error(return_type, result, field_nodes) return self.execute_fields(return_type, result, path, sub_field_nodes) def collect_subfields( self, return_type: GraphQLObjectType, field_nodes: List[FieldNode] ) -> Dict[str, List[FieldNode]]: """Collect subfields. A cached collection of relevant subfields with regard to the return type is kept in the execution context as ``_subfields_cache``. This ensures the subfields are not repeatedly calculated, which saves overhead when resolving lists of values. """ cache = self._subfields_cache # We cannot use the field_nodes themselves as key for the cache, since they # are not hashable as a list. We also do not want to use the field_nodes # themselves (converted to a tuple) as keys, since hashing them is slow. # Therefore we use the ids of the field_nodes as keys. Note that we do not # use the id of the list, since we want to hit the cache for all lists of # the same nodes, not only for the same list of nodes. Also, the list id may # even be reused, in which case we would get wrong results from the cache. key = ( (return_type, id(field_nodes[0])) if len(field_nodes) == 1 # optimize most frequent case else tuple((return_type, *map(id, field_nodes))) ) sub_field_nodes = cache.get(key) if sub_field_nodes is None: sub_field_nodes = collect_sub_fields( self.schema, self.fragments, self.variable_values, return_type, field_nodes, ) cache[key] = sub_field_nodes return sub_field_nodes def execute( schema: GraphQLSchema, document: DocumentNode, root_value: Any = None, context_value: Any = None, variable_values: Optional[Dict[str, Any]] = None, operation_name: Optional[str] = None, field_resolver: Optional[GraphQLFieldResolver] = None, type_resolver: Optional[GraphQLTypeResolver] = None, subscribe_field_resolver: Optional[GraphQLFieldResolver] = None, middleware: Optional[Middleware] = None, execution_context_class: Optional[Type["ExecutionContext"]] = None, is_awaitable: Optional[Callable[[Any], bool]] = None, ) -> AwaitableOrValue[ExecutionResult]: """Execute a GraphQL operation. Implements the "Executing requests" section of the GraphQL specification. Returns an ExecutionResult (if all encountered resolvers are synchronous), or a coroutine object eventually yielding an ExecutionResult. If the arguments to this function do not result in a legal execution context, a GraphQLError will be thrown immediately explaining the invalid input. """ # If arguments are missing or incorrect, throw an error. assert_valid_execution_arguments(schema, document, variable_values) if execution_context_class is None: execution_context_class = ExecutionContext # If a valid execution context cannot be created due to incorrect arguments, # a "Response" with only errors is returned. exe_context = execution_context_class.build( schema, document, root_value, context_value, variable_values, operation_name, field_resolver, type_resolver, subscribe_field_resolver, middleware, is_awaitable, ) # Return early errors if execution context failed. if isinstance(exe_context, list): return ExecutionResult(data=None, errors=exe_context) # Return a possible coroutine object that will eventually yield the data described # by the "Response" section of the GraphQL specification. # # If errors are encountered while executing a GraphQL field, only that field and # its descendants will be omitted, and sibling fields will still be executed. An # execution which encounters errors will still result in a coroutine object that # can be executed without errors. # # Errors from sub-fields of a NonNull type may propagate to the top level, # at which point we still log the error and null the parent field, which # in this case is the entire response. errors = exe_context.errors build_response = exe_context.build_response try: operation = exe_context.operation result = exe_context.execute_operation(operation, root_value) if exe_context.is_awaitable(result): # noinspection PyShadowingNames async def await_result() -> Any: try: return build_response(await result, errors) # type: ignore except GraphQLError as error: errors.append(error) return build_response(None, errors) return await_result() except GraphQLError as error: errors.append(error) return build_response(None, errors) else: return build_response(result, errors) # type: ignore def assume_not_awaitable(_value: Any) -> bool: """Replacement for isawaitable if everything is assumed to be synchronous.""" return False def execute_sync( schema: GraphQLSchema, document: DocumentNode, root_value: Any = None, context_value: Any = 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: Optional[Type["ExecutionContext"]] = None, check_sync: bool = False, ) -> ExecutionResult: """Execute a GraphQL operation synchronously. Also implements the "Executing requests" section of the GraphQL specification. However, it guarantees to complete synchronously (or throw an error) assuming that all field resolvers are also synchronous. Set check_sync to True to still run checks that no awaitable values are returned. """ is_awaitable = ( check_sync if callable(check_sync) else (None if check_sync else assume_not_awaitable) ) result = execute( schema, document, root_value, context_value, variable_values, operation_name, field_resolver, type_resolver, None, middleware, execution_context_class, is_awaitable, ) # Assert that the execution was synchronous. if isawaitable(result): ensure_future(result).cancel() raise RuntimeError("GraphQL execution failed to complete synchronously.") return result def assert_valid_execution_arguments( schema: GraphQLSchema, document: DocumentNode, raw_variable_values: Optional[Dict[str, Any]] = None, ) -> None: """Check that the arguments are acceptable. Essential assertions before executing to provide developer feedback for improper use of the GraphQL library. For internal use only. """ if not document: raise TypeError("Must provide document.") # If the schema used for execution is invalid, throw an error. assert_valid_schema(schema) # Variables, if provided, must be a dictionary. if not (raw_variable_values is None or isinstance(raw_variable_values, dict)): raise TypeError( "Variable values must be provided as a dictionary" " with variable names as keys. Perhaps look to see" " if an unparsed JSON string was provided." ) def get_field_def( schema: GraphQLSchema, parent_type: GraphQLObjectType, field_node: FieldNode ) -> GraphQLField: """Get field definition. This method looks up the field on the given type definition. It has special casing for the three introspection fields, ``__schema``, ``__type`, and ``__typename``. ``__typename`` is special because it can always be queried as a field, even in situations where no other fields are allowed, like on a Union. ``__schema`` and ``__type`` could get automatically added to the query type, but that would require mutating type definitions, which would cause issues. For internal use only. """ field_name = field_node.name.value if field_name == "__schema" and schema.query_type == parent_type: return SchemaMetaFieldDef elif field_name == "__type" and schema.query_type == parent_type: return TypeMetaFieldDef elif field_name == "__typename": return TypeNameMetaFieldDef return parent_type.fields.get(field_name) def invalid_return_type_error( return_type: GraphQLObjectType, result: Any, field_nodes: List[FieldNode] ) -> GraphQLError: """Create a GraphQLError for an invalid return type.""" return GraphQLError( f"Expected value of type '{return_type.name}' but got: {inspect(result)}.", field_nodes, ) def get_typename(value: Any) -> Optional[str]: """Get the ``__typename`` property of the given value.""" if isinstance(value, Mapping): return value.get("__typename") # need to de-mangle the attribute assumed to be "private" in Python for cls in value.__class__.__mro__: __typename = getattr(value, f"_{cls.__name__}__typename", None) if __typename: return __typename return None def default_type_resolver( value: Any, info: GraphQLResolveInfo, abstract_type: GraphQLAbstractType ) -> AwaitableOrValue[Optional[str]]: """Default type resolver function. If a resolve_type function is not given, then a default resolve behavior is used which attempts two strategies: First, See if the provided value has a ``__typename`` field defined, if so, use that value as name of the resolved type. Otherwise, test each possible type for the abstract type by calling :meth:`~graphql.type.GraphQLObjectType.is_type_of` for the object being coerced, returning the first type that matches. """ # First, look for `__typename`. type_name = get_typename(value) if isinstance(type_name, str): return type_name # Otherwise, test each possible type. possible_types = info.schema.get_possible_types(abstract_type) is_awaitable = info.is_awaitable awaitable_is_type_of_results: List[Awaitable] = [] append_awaitable_results = awaitable_is_type_of_results.append awaitable_types: List[GraphQLObjectType] = [] append_awaitable_types = awaitable_types.append for type_ in possible_types: if type_.is_type_of: is_type_of_result = type_.is_type_of(value, info) if is_awaitable(is_type_of_result): append_awaitable_results(cast(Awaitable, is_type_of_result)) append_awaitable_types(type_) elif is_type_of_result: return type_.name if awaitable_is_type_of_results: # noinspection PyShadowingNames async def get_type() -> Optional[str]: is_type_of_results = await gather(*awaitable_is_type_of_results) for is_type_of_result, type_ in zip(is_type_of_results, awaitable_types): if is_type_of_result: return type_.name return None return get_type() return None def default_field_resolver(source: Any, info: GraphQLResolveInfo, **args: Any) -> Any: """Default field resolver. If a resolve function is not given, then a default resolve behavior is used which takes the property of the source object of the same name as the field and returns it as the result, or if it's a function, returns the result of calling that function while passing along args and context. For dictionaries, the field names are used as keys, for all other objects they are used as attribute names. """ # Ensure source is a value for which property access is acceptable. field_name = info.field_name value = ( source.get(field_name) if isinstance(source, Mapping) else getattr(source, field_name, None) ) if callable(value): return value(info, **args) return value