import asyncio import inspect from contextlib import contextmanager from copy import deepcopy from typing import ( Any, Callable, Dict, List, Mapping, Optional, Sequence, Tuple, Type, Union, cast, ) from fastapi import params from fastapi.concurrency import ( AsyncExitStack, _fake_asynccontextmanager, asynccontextmanager, contextmanager_in_threadpool, ) from fastapi.dependencies.models import Dependant, SecurityRequirement from fastapi.logger import logger from fastapi.security.base import SecurityBase from fastapi.security.oauth2 import OAuth2, SecurityScopes from fastapi.security.open_id_connect_url import OpenIdConnect from fastapi.utils import create_response_field, get_path_param_names from pydantic import BaseModel, create_model from pydantic.error_wrappers import ErrorWrapper from pydantic.errors import MissingError from pydantic.fields import ( SHAPE_LIST, SHAPE_SEQUENCE, SHAPE_SET, SHAPE_SINGLETON, SHAPE_TUPLE, SHAPE_TUPLE_ELLIPSIS, FieldInfo, ModelField, Required, ) from pydantic.schema import get_annotation_from_field_info from pydantic.typing import ForwardRef, evaluate_forwardref from pydantic.utils import lenient_issubclass from starlette.background import BackgroundTasks from starlette.concurrency import run_in_threadpool from starlette.datastructures import FormData, Headers, QueryParams, UploadFile from starlette.requests import HTTPConnection, Request from starlette.responses import Response from starlette.websockets import WebSocket sequence_shapes = { SHAPE_LIST, SHAPE_SET, SHAPE_TUPLE, SHAPE_SEQUENCE, SHAPE_TUPLE_ELLIPSIS, } sequence_types = (list, set, tuple) sequence_shape_to_type = { SHAPE_LIST: list, SHAPE_SET: set, SHAPE_TUPLE: tuple, SHAPE_SEQUENCE: list, SHAPE_TUPLE_ELLIPSIS: list, } multipart_not_installed_error = ( 'Form data requires "python-multipart" to be installed. \n' 'You can install "python-multipart" with: \n\n' "pip install python-multipart\n" ) multipart_incorrect_install_error = ( 'Form data requires "python-multipart" to be installed. ' 'It seems you installed "multipart" instead. \n' 'You can remove "multipart" with: \n\n' "pip uninstall multipart\n\n" 'And then install "python-multipart" with: \n\n' "pip install python-multipart\n" ) def check_file_field(field: ModelField) -> None: field_info = field.field_info if isinstance(field_info, params.Form): try: # __version__ is available in both multiparts, and can be mocked from multipart import __version__ # type: ignore assert __version__ try: # parse_options_header is only available in the right multipart from multipart.multipart import parse_options_header # type: ignore assert parse_options_header except ImportError: logger.error(multipart_incorrect_install_error) raise RuntimeError(multipart_incorrect_install_error) except ImportError: logger.error(multipart_not_installed_error) raise RuntimeError(multipart_not_installed_error) def get_param_sub_dependant( *, param: inspect.Parameter, path: str, security_scopes: Optional[List[str]] = None ) -> Dependant: depends: params.Depends = param.default if depends.dependency: dependency = depends.dependency else: dependency = param.annotation return get_sub_dependant( depends=depends, dependency=dependency, path=path, name=param.name, security_scopes=security_scopes, ) def get_parameterless_sub_dependant(*, depends: params.Depends, path: str) -> Dependant: assert callable( depends.dependency ), "A parameter-less dependency must have a callable dependency" return get_sub_dependant(depends=depends, dependency=depends.dependency, path=path) def get_sub_dependant( *, depends: params.Depends, dependency: Callable[..., Any], path: str, name: Optional[str] = None, security_scopes: Optional[List[str]] = None, ) -> Dependant: security_requirement = None security_scopes = security_scopes or [] if isinstance(depends, params.Security): dependency_scopes = depends.scopes security_scopes.extend(dependency_scopes) if isinstance(dependency, SecurityBase): use_scopes: List[str] = [] if isinstance(dependency, (OAuth2, OpenIdConnect)): use_scopes = security_scopes security_requirement = SecurityRequirement( security_scheme=dependency, scopes=use_scopes ) sub_dependant = get_dependant( path=path, call=dependency, name=name, security_scopes=security_scopes, use_cache=depends.use_cache, ) if security_requirement: sub_dependant.security_requirements.append(security_requirement) sub_dependant.security_scopes = security_scopes return sub_dependant CacheKey = Tuple[Optional[Callable[..., Any]], Tuple[str, ...]] def get_flat_dependant( dependant: Dependant, *, skip_repeats: bool = False, visited: Optional[List[CacheKey]] = None, ) -> Dependant: if visited is None: visited = [] visited.append(dependant.cache_key) flat_dependant = Dependant( path_params=dependant.path_params.copy(), query_params=dependant.query_params.copy(), header_params=dependant.header_params.copy(), cookie_params=dependant.cookie_params.copy(), body_params=dependant.body_params.copy(), security_schemes=dependant.security_requirements.copy(), use_cache=dependant.use_cache, path=dependant.path, ) for sub_dependant in dependant.dependencies: if skip_repeats and sub_dependant.cache_key in visited: continue flat_sub = get_flat_dependant( sub_dependant, skip_repeats=skip_repeats, visited=visited ) flat_dependant.path_params.extend(flat_sub.path_params) flat_dependant.query_params.extend(flat_sub.query_params) flat_dependant.header_params.extend(flat_sub.header_params) flat_dependant.cookie_params.extend(flat_sub.cookie_params) flat_dependant.body_params.extend(flat_sub.body_params) flat_dependant.security_requirements.extend(flat_sub.security_requirements) return flat_dependant def get_flat_params(dependant: Dependant) -> List[ModelField]: flat_dependant = get_flat_dependant(dependant, skip_repeats=True) return ( flat_dependant.path_params + flat_dependant.query_params + flat_dependant.header_params + flat_dependant.cookie_params ) def is_scalar_field(field: ModelField) -> bool: field_info = field.field_info if not ( field.shape == SHAPE_SINGLETON and not lenient_issubclass(field.type_, BaseModel) and not lenient_issubclass(field.type_, sequence_types + (dict,)) and not isinstance(field_info, params.Body) ): return False if field.sub_fields: if not all(is_scalar_field(f) for f in field.sub_fields): return False return True def is_scalar_sequence_field(field: ModelField) -> bool: if (field.shape in sequence_shapes) and not lenient_issubclass( field.type_, BaseModel ): if field.sub_fields is not None: for sub_field in field.sub_fields: if not is_scalar_field(sub_field): return False return True if lenient_issubclass(field.type_, sequence_types): return True return False def get_typed_signature(call: Callable[..., Any]) -> inspect.Signature: signature = inspect.signature(call) globalns = getattr(call, "__globals__", {}) typed_params = [ inspect.Parameter( name=param.name, kind=param.kind, default=param.default, annotation=get_typed_annotation(param, globalns), ) for param in signature.parameters.values() ] typed_signature = inspect.Signature(typed_params) return typed_signature def get_typed_annotation(param: inspect.Parameter, globalns: Dict[str, Any]) -> Any: annotation = param.annotation if isinstance(annotation, str): annotation = ForwardRef(annotation) annotation = evaluate_forwardref(annotation, globalns, globalns) return annotation async_contextmanager_dependencies_error = """ FastAPI dependencies with yield require Python 3.7 or above, or the backports for Python 3.6, installed with: pip install async-exit-stack async-generator """ def check_dependency_contextmanagers() -> None: if AsyncExitStack is None or asynccontextmanager == _fake_asynccontextmanager: raise RuntimeError(async_contextmanager_dependencies_error) # pragma: no cover def get_dependant( *, path: str, call: Callable[..., Any], name: Optional[str] = None, security_scopes: Optional[List[str]] = None, use_cache: bool = True, ) -> Dependant: path_param_names = get_path_param_names(path) endpoint_signature = get_typed_signature(call) signature_params = endpoint_signature.parameters if is_gen_callable(call) or is_async_gen_callable(call): check_dependency_contextmanagers() dependant = Dependant(call=call, name=name, path=path, use_cache=use_cache) for param_name, param in signature_params.items(): if isinstance(param.default, params.Depends): sub_dependant = get_param_sub_dependant( param=param, path=path, security_scopes=security_scopes ) dependant.dependencies.append(sub_dependant) continue if add_non_field_param_to_dependency(param=param, dependant=dependant): continue param_field = get_param_field( param=param, default_field_info=params.Query, param_name=param_name ) if param_name in path_param_names: assert is_scalar_field( field=param_field ), "Path params must be of one of the supported types" if isinstance(param.default, params.Path): ignore_default = False else: ignore_default = True param_field = get_param_field( param=param, param_name=param_name, default_field_info=params.Path, force_type=params.ParamTypes.path, ignore_default=ignore_default, ) add_param_to_fields(field=param_field, dependant=dependant) elif is_scalar_field(field=param_field): add_param_to_fields(field=param_field, dependant=dependant) elif isinstance( param.default, (params.Query, params.Header) ) and is_scalar_sequence_field(param_field): add_param_to_fields(field=param_field, dependant=dependant) else: field_info = param_field.field_info assert isinstance( field_info, params.Body ), f"Param: {param_field.name} can only be a request body, using Body(...)" dependant.body_params.append(param_field) return dependant def add_non_field_param_to_dependency( *, param: inspect.Parameter, dependant: Dependant ) -> Optional[bool]: if lenient_issubclass(param.annotation, Request): dependant.request_param_name = param.name return True elif lenient_issubclass(param.annotation, WebSocket): dependant.websocket_param_name = param.name return True elif lenient_issubclass(param.annotation, HTTPConnection): dependant.http_connection_param_name = param.name return True elif lenient_issubclass(param.annotation, Response): dependant.response_param_name = param.name return True elif lenient_issubclass(param.annotation, BackgroundTasks): dependant.background_tasks_param_name = param.name return True elif lenient_issubclass(param.annotation, SecurityScopes): dependant.security_scopes_param_name = param.name return True return None def get_param_field( *, param: inspect.Parameter, param_name: str, default_field_info: Type[params.Param] = params.Param, force_type: Optional[params.ParamTypes] = None, ignore_default: bool = False, ) -> ModelField: default_value = Required had_schema = False if not param.default == param.empty and ignore_default is False: default_value = param.default if isinstance(default_value, FieldInfo): had_schema = True field_info = default_value default_value = field_info.default if ( isinstance(field_info, params.Param) and getattr(field_info, "in_", None) is None ): field_info.in_ = default_field_info.in_ if force_type: field_info.in_ = force_type # type: ignore else: field_info = default_field_info(default_value) required = default_value == Required annotation: Any = Any if not param.annotation == param.empty: annotation = param.annotation annotation = get_annotation_from_field_info(annotation, field_info, param_name) if not field_info.alias and getattr(field_info, "convert_underscores", None): alias = param.name.replace("_", "-") else: alias = field_info.alias or param.name field = create_response_field( name=param.name, type_=annotation, default=None if required else default_value, alias=alias, required=required, field_info=field_info, ) field.required = required if not had_schema and not is_scalar_field(field=field): field.field_info = params.Body(field_info.default) return field def add_param_to_fields(*, field: ModelField, dependant: Dependant) -> None: field_info = cast(params.Param, field.field_info) if field_info.in_ == params.ParamTypes.path: dependant.path_params.append(field) elif field_info.in_ == params.ParamTypes.query: dependant.query_params.append(field) elif field_info.in_ == params.ParamTypes.header: dependant.header_params.append(field) else: assert ( field_info.in_ == params.ParamTypes.cookie ), f"non-body parameters must be in path, query, header or cookie: {field.name}" dependant.cookie_params.append(field) def is_coroutine_callable(call: Callable[..., Any]) -> bool: if inspect.isroutine(call): return inspect.iscoroutinefunction(call) if inspect.isclass(call): return False call = getattr(call, "__call__", None) return inspect.iscoroutinefunction(call) def is_async_gen_callable(call: Callable[..., Any]) -> bool: if inspect.isasyncgenfunction(call): return True call = getattr(call, "__call__", None) return inspect.isasyncgenfunction(call) def is_gen_callable(call: Callable[..., Any]) -> bool: if inspect.isgeneratorfunction(call): return True call = getattr(call, "__call__", None) return inspect.isgeneratorfunction(call) async def solve_generator( *, call: Callable[..., Any], stack: AsyncExitStack, sub_values: Dict[str, Any] ) -> Any: if is_gen_callable(call): cm = contextmanager_in_threadpool(contextmanager(call)(**sub_values)) elif is_async_gen_callable(call): if not inspect.isasyncgenfunction(call): # asynccontextmanager from the async_generator backfill pre python3.7 # does not support callables that are not functions or methods. # See https://github.com/python-trio/async_generator/issues/32 # # Expand the callable class into its __call__ method before decorating it. # This approach will work on newer python versions as well. call = getattr(call, "__call__", None) cm = asynccontextmanager(call)(**sub_values) return await stack.enter_async_context(cm) async def solve_dependencies( *, request: Union[Request, WebSocket], dependant: Dependant, body: Optional[Union[Dict[str, Any], FormData]] = None, background_tasks: Optional[BackgroundTasks] = None, response: Optional[Response] = None, dependency_overrides_provider: Optional[Any] = None, dependency_cache: Optional[Dict[Tuple[Callable[..., Any], Tuple[str]], Any]] = None, ) -> Tuple[ Dict[str, Any], List[ErrorWrapper], Optional[BackgroundTasks], Response, Dict[Tuple[Callable[..., Any], Tuple[str]], Any], ]: values: Dict[str, Any] = {} errors: List[ErrorWrapper] = [] response = response or Response( content=None, status_code=None, # type: ignore headers=None, # type: ignore # in Starlette media_type=None, # type: ignore # in Starlette background=None, # type: ignore # in Starlette ) dependency_cache = dependency_cache or {} sub_dependant: Dependant for sub_dependant in dependant.dependencies: sub_dependant.call = cast(Callable[..., Any], sub_dependant.call) sub_dependant.cache_key = cast( Tuple[Callable[..., Any], Tuple[str]], sub_dependant.cache_key ) call = sub_dependant.call use_sub_dependant = sub_dependant if ( dependency_overrides_provider and dependency_overrides_provider.dependency_overrides ): original_call = sub_dependant.call call = getattr( dependency_overrides_provider, "dependency_overrides", {} ).get(original_call, original_call) use_path: str = sub_dependant.path # type: ignore use_sub_dependant = get_dependant( path=use_path, call=call, name=sub_dependant.name, security_scopes=sub_dependant.security_scopes, ) use_sub_dependant.security_scopes = sub_dependant.security_scopes solved_result = await solve_dependencies( request=request, dependant=use_sub_dependant, body=body, background_tasks=background_tasks, response=response, dependency_overrides_provider=dependency_overrides_provider, dependency_cache=dependency_cache, ) ( sub_values, sub_errors, background_tasks, _, # the subdependency returns the same response we have sub_dependency_cache, ) = solved_result dependency_cache.update(sub_dependency_cache) if sub_errors: errors.extend(sub_errors) continue if sub_dependant.use_cache and sub_dependant.cache_key in dependency_cache: solved = dependency_cache[sub_dependant.cache_key] elif is_gen_callable(call) or is_async_gen_callable(call): stack = request.scope.get("fastapi_astack") if stack is None: raise RuntimeError( async_contextmanager_dependencies_error ) # pragma: no cover solved = await solve_generator( call=call, stack=stack, sub_values=sub_values ) elif is_coroutine_callable(call): solved = await call(**sub_values) else: solved = await run_in_threadpool(call, **sub_values) if sub_dependant.name is not None: values[sub_dependant.name] = solved if sub_dependant.cache_key not in dependency_cache: dependency_cache[sub_dependant.cache_key] = solved path_values, path_errors = request_params_to_args( dependant.path_params, request.path_params ) query_values, query_errors = request_params_to_args( dependant.query_params, request.query_params ) header_values, header_errors = request_params_to_args( dependant.header_params, request.headers ) cookie_values, cookie_errors = request_params_to_args( dependant.cookie_params, request.cookies ) values.update(path_values) values.update(query_values) values.update(header_values) values.update(cookie_values) errors += path_errors + query_errors + header_errors + cookie_errors if dependant.body_params: ( body_values, body_errors, ) = await request_body_to_args( # body_params checked above required_params=dependant.body_params, received_body=body ) values.update(body_values) errors.extend(body_errors) if dependant.http_connection_param_name: values[dependant.http_connection_param_name] = request if dependant.request_param_name and isinstance(request, Request): values[dependant.request_param_name] = request elif dependant.websocket_param_name and isinstance(request, WebSocket): values[dependant.websocket_param_name] = request if dependant.background_tasks_param_name: if background_tasks is None: background_tasks = BackgroundTasks() values[dependant.background_tasks_param_name] = background_tasks if dependant.response_param_name: values[dependant.response_param_name] = response if dependant.security_scopes_param_name: values[dependant.security_scopes_param_name] = SecurityScopes( scopes=dependant.security_scopes ) return values, errors, background_tasks, response, dependency_cache def request_params_to_args( required_params: Sequence[ModelField], received_params: Union[Mapping[str, Any], QueryParams, Headers], ) -> Tuple[Dict[str, Any], List[ErrorWrapper]]: values = {} errors = [] for field in required_params: if is_scalar_sequence_field(field) and isinstance( received_params, (QueryParams, Headers) ): value = received_params.getlist(field.alias) or field.default else: value = received_params.get(field.alias) field_info = field.field_info assert isinstance( field_info, params.Param ), "Params must be subclasses of Param" if value is None: if field.required: errors.append( ErrorWrapper( MissingError(), loc=(field_info.in_.value, field.alias) ) ) else: values[field.name] = deepcopy(field.default) continue v_, errors_ = field.validate( value, values, loc=(field_info.in_.value, field.alias) ) if isinstance(errors_, ErrorWrapper): errors.append(errors_) elif isinstance(errors_, list): errors.extend(errors_) else: values[field.name] = v_ return values, errors async def request_body_to_args( required_params: List[ModelField], received_body: Optional[Union[Dict[str, Any], FormData]], ) -> Tuple[Dict[str, Any], List[ErrorWrapper]]: values = {} errors = [] if required_params: field = required_params[0] field_info = field.field_info embed = getattr(field_info, "embed", None) field_alias_omitted = len(required_params) == 1 and not embed if field_alias_omitted: received_body = {field.alias: received_body} for field in required_params: loc: Tuple[str, ...] if field_alias_omitted: loc = ("body",) else: loc = ("body", field.alias) value: Optional[Any] = None if received_body is not None: if ( field.shape in sequence_shapes or field.type_ in sequence_types ) and isinstance(received_body, FormData): value = received_body.getlist(field.alias) else: try: value = received_body.get(field.alias) except AttributeError: errors.append(get_missing_field_error(loc)) continue if ( value is None or (isinstance(field_info, params.Form) and value == "") or ( isinstance(field_info, params.Form) and field.shape in sequence_shapes and len(value) == 0 ) ): if field.required: errors.append(get_missing_field_error(loc)) else: values[field.name] = deepcopy(field.default) continue if ( isinstance(field_info, params.File) and lenient_issubclass(field.type_, bytes) and isinstance(value, UploadFile) ): value = await value.read() elif ( field.shape in sequence_shapes and isinstance(field_info, params.File) and lenient_issubclass(field.type_, bytes) and isinstance(value, sequence_types) ): awaitables = [sub_value.read() for sub_value in value] contents = await asyncio.gather(*awaitables) value = sequence_shape_to_type[field.shape](contents) v_, errors_ = field.validate(value, values, loc=loc) if isinstance(errors_, ErrorWrapper): errors.append(errors_) elif isinstance(errors_, list): errors.extend(errors_) else: values[field.name] = v_ return values, errors def get_missing_field_error(loc: Tuple[str, ...]) -> ErrorWrapper: missing_field_error = ErrorWrapper(MissingError(), loc=loc) return missing_field_error def get_schema_compatible_field(*, field: ModelField) -> ModelField: out_field = field if lenient_issubclass(field.type_, UploadFile): use_type: type = bytes if field.shape in sequence_shapes: use_type = List[bytes] out_field = create_response_field( name=field.name, type_=use_type, class_validators=field.class_validators, model_config=field.model_config, default=field.default, required=field.required, alias=field.alias, field_info=field.field_info, ) return out_field def get_body_field(*, dependant: Dependant, name: str) -> Optional[ModelField]: flat_dependant = get_flat_dependant(dependant) if not flat_dependant.body_params: return None first_param = flat_dependant.body_params[0] field_info = first_param.field_info embed = getattr(field_info, "embed", None) body_param_names_set = {param.name for param in flat_dependant.body_params} if len(body_param_names_set) == 1 and not embed: final_field = get_schema_compatible_field(field=first_param) check_file_field(final_field) return final_field # If one field requires to embed, all have to be embedded # in case a sub-dependency is evaluated with a single unique body field # That is combined (embedded) with other body fields for param in flat_dependant.body_params: setattr(param.field_info, "embed", True) model_name = "Body_" + name BodyModel = create_model(model_name) for f in flat_dependant.body_params: BodyModel.__fields__[f.name] = get_schema_compatible_field(field=f) required = any(True for f in flat_dependant.body_params if f.required) BodyFieldInfo_kwargs: Dict[str, Any] = dict(default=None) if any(isinstance(f.field_info, params.File) for f in flat_dependant.body_params): BodyFieldInfo: Type[params.Body] = params.File elif any(isinstance(f.field_info, params.Form) for f in flat_dependant.body_params): BodyFieldInfo = params.Form else: BodyFieldInfo = params.Body body_param_media_types = [ getattr(f.field_info, "media_type") for f in flat_dependant.body_params if isinstance(f.field_info, params.Body) ] if len(set(body_param_media_types)) == 1: BodyFieldInfo_kwargs["media_type"] = body_param_media_types[0] final_field = create_response_field( name="body", type_=BodyModel, required=required, alias="body", field_info=BodyFieldInfo(**BodyFieldInfo_kwargs), ) check_file_field(final_field) return final_field