import inspect
from contextlib import contextmanager
from copy import deepcopy
from typing import (
Any,
Callable,
Coroutine,
Dict,
ForwardRef,
List,
Mapping,
Optional,
Sequence,
Tuple,
Type,
Union,
cast,
)
import anyio
from fastapi import params
from fastapi._compat import (
PYDANTIC_V2,
ErrorWrapper,
ModelField,
Required,
Undefined,
_regenerate_error_with_loc,
copy_field_info,
create_body_model,
evaluate_forwardref,
field_annotation_is_scalar,
get_annotation_from_field_info,
get_missing_field_error,
is_bytes_field,
is_bytes_sequence_field,
is_scalar_field,
is_scalar_sequence_field,
is_sequence_field,
is_uploadfile_or_nonable_uploadfile_annotation,
is_uploadfile_sequence_annotation,
lenient_issubclass,
sequence_types,
serialize_sequence_value,
value_is_sequence,
)
from fastapi.concurrency import (
AsyncExitStack,
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.fields import FieldInfo
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
from typing_extensions import Annotated, get_args, get_origin
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) from None
except ImportError:
logger.error(multipart_not_installed_error)
raise RuntimeError(multipart_not_installed_error) from None
def get_param_sub_dependant(
*,
param_name: str,
depends: params.Depends,
path: str,
security_scopes: Optional[List[str]] = None,
) -> Dependant:
assert depends.dependency
return get_sub_dependant(
depends=depends,
dependency=depends.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)
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 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.annotation, globalns),
)
for param in signature.parameters.values()
]
typed_signature = inspect.Signature(typed_params)
return typed_signature
def get_typed_annotation(annotation: Any, globalns: Dict[str, Any]) -> Any:
if isinstance(annotation, str):
annotation = ForwardRef(annotation)
annotation = evaluate_forwardref(annotation, globalns, globalns)
return annotation
def get_typed_return_annotation(call: Callable[..., Any]) -> Any:
signature = inspect.signature(call)
annotation = signature.return_annotation
if annotation is inspect.Signature.empty:
return None
globalns = getattr(call, "__globals__", {})
return get_typed_annotation(annotation, globalns)
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
dependant = Dependant(
call=call,
name=name,
path=path,
security_scopes=security_scopes,
use_cache=use_cache,
)
for param_name, param in signature_params.items():
is_path_param = param_name in path_param_names
type_annotation, depends, param_field = analyze_param(
param_name=param_name,
annotation=param.annotation,
value=param.default,
is_path_param=is_path_param,
)
if depends is not None:
sub_dependant = get_param_sub_dependant(
param_name=param_name,
depends=depends,
path=path,
security_scopes=security_scopes,
)
dependant.dependencies.append(sub_dependant)
continue
if add_non_field_param_to_dependency(
param_name=param_name,
type_annotation=type_annotation,
dependant=dependant,
):
assert (
param_field is None
), f"Cannot specify multiple FastAPI annotations for {param_name!r}"
continue
assert param_field is not None
if is_body_param(param_field=param_field, is_path_param=is_path_param):
dependant.body_params.append(param_field)
else:
add_param_to_fields(field=param_field, dependant=dependant)
return dependant
def add_non_field_param_to_dependency(
*, param_name: str, type_annotation: Any, dependant: Dependant
) -> Optional[bool]:
if lenient_issubclass(type_annotation, Request):
dependant.request_param_name = param_name
return True
elif lenient_issubclass(type_annotation, WebSocket):
dependant.websocket_param_name = param_name
return True
elif lenient_issubclass(type_annotation, HTTPConnection):
dependant.http_connection_param_name = param_name
return True
elif lenient_issubclass(type_annotation, Response):
dependant.response_param_name = param_name
return True
elif lenient_issubclass(type_annotation, BackgroundTasks):
dependant.background_tasks_param_name = param_name
return True
elif lenient_issubclass(type_annotation, SecurityScopes):
dependant.security_scopes_param_name = param_name
return True
return None
def analyze_param(
*,
param_name: str,
annotation: Any,
value: Any,
is_path_param: bool,
) -> Tuple[Any, Optional[params.Depends], Optional[ModelField]]:
field_info = None
depends = None
type_annotation: Any = Any
if (
annotation is not inspect.Signature.empty
and get_origin(annotation) is Annotated
):
annotated_args = get_args(annotation)
type_annotation = annotated_args[0]
fastapi_annotations = [
arg
for arg in annotated_args[1:]
if isinstance(arg, (FieldInfo, params.Depends))
]
assert (
len(fastapi_annotations) <= 1
), f"Cannot specify multiple `Annotated` FastAPI arguments for {param_name!r}"
fastapi_annotation = next(iter(fastapi_annotations), None)
if isinstance(fastapi_annotation, FieldInfo):
# Copy `field_info` because we mutate `field_info.default` below.
field_info = copy_field_info(
field_info=fastapi_annotation, annotation=annotation
)
assert field_info.default is Undefined or field_info.default is Required, (
f"`{field_info.__class__.__name__}` default value cannot be set in"
f" `Annotated` for {param_name!r}. Set the default value with `=` instead."
)
if value is not inspect.Signature.empty:
assert not is_path_param, "Path parameters cannot have default values"
field_info.default = value
else:
field_info.default = Required
elif isinstance(fastapi_annotation, params.Depends):
depends = fastapi_annotation
elif annotation is not inspect.Signature.empty:
type_annotation = annotation
if isinstance(value, params.Depends):
assert depends is None, (
"Cannot specify `Depends` in `Annotated` and default value"
f" together for {param_name!r}"
)
assert field_info is None, (
"Cannot specify a FastAPI annotation in `Annotated` and `Depends` as a"
f" default value together for {param_name!r}"
)
depends = value
elif isinstance(value, FieldInfo):
assert field_info is None, (
"Cannot specify FastAPI annotations in `Annotated` and default value"
f" together for {param_name!r}"
)
field_info = value
if PYDANTIC_V2:
field_info.annotation = type_annotation
if depends is not None and depends.dependency is None:
depends.dependency = type_annotation
if lenient_issubclass(
type_annotation,
(Request, WebSocket, HTTPConnection, Response, BackgroundTasks, SecurityScopes),
):
assert depends is None, f"Cannot specify `Depends` for type {type_annotation!r}"
assert (
field_info is None
), f"Cannot specify FastAPI annotation for type {type_annotation!r}"
elif field_info is None and depends is None:
default_value = value if value is not inspect.Signature.empty else Required
if is_path_param:
# We might check here that `default_value is Required`, but the fact is that the same
# parameter might sometimes be a path parameter and sometimes not. See
# `tests/test_infer_param_optionality.py` for an example.
field_info = params.Path(annotation=type_annotation)
elif is_uploadfile_or_nonable_uploadfile_annotation(
type_annotation
) or is_uploadfile_sequence_annotation(type_annotation):
field_info = params.File(annotation=type_annotation, default=default_value)
elif not field_annotation_is_scalar(annotation=type_annotation):
field_info = params.Body(annotation=type_annotation, default=default_value)
else:
field_info = params.Query(annotation=type_annotation, default=default_value)
field = None
if field_info is not None:
if is_path_param:
assert isinstance(field_info, params.Path), (
f"Cannot use `{field_info.__class__.__name__}` for path param"
f" {param_name!r}"
)
elif (
isinstance(field_info, params.Param)
and getattr(field_info, "in_", None) is None
):
field_info.in_ = params.ParamTypes.query
use_annotation = get_annotation_from_field_info(
type_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_info.alias = alias
field = create_response_field(
name=param_name,
type_=use_annotation,
default=field_info.default,
alias=alias,
required=field_info.default in (Required, Undefined),
field_info=field_info,
)
return type_annotation, depends, field
def is_body_param(*, param_field: ModelField, is_path_param: bool) -> bool:
if is_path_param:
assert is_scalar_field(
field=param_field
), "Path params must be of one of the supported types"
return False
elif is_scalar_field(field=param_field):
return False
elif isinstance(
param_field.field_info, (params.Query, params.Header)
) and is_scalar_sequence_field(param_field):
return False
else:
assert isinstance(
param_field.field_info, params.Body
), f"Param: {param_field.name} can only be a request body, using Body()"
return True
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
dunder_call = getattr(call, "__call__", None) # noqa: B004
return inspect.iscoroutinefunction(dunder_call)
def is_async_gen_callable(call: Callable[..., Any]) -> bool:
if inspect.isasyncgenfunction(call):
return True
dunder_call = getattr(call, "__call__", None) # noqa: B004
return inspect.isasyncgenfunction(dunder_call)
def is_gen_callable(call: Callable[..., Any]) -> bool:
if inspect.isgeneratorfunction(call):
return True
dunder_call = getattr(call, "__call__", None) # noqa: B004
return inspect.isgeneratorfunction(dunder_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):
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[Any],
Optional[BackgroundTasks],
Response,
Dict[Tuple[Callable[..., Any], Tuple[str]], Any],
]:
values: Dict[str, Any] = {}
errors: List[Any] = []
if response is None:
response = Response()
del response.headers["content-length"]
response.status_code = None # type: ignore
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,
)
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")
assert isinstance(stack, AsyncExitStack)
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[Any]]:
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"
loc = (field_info.in_.value, field.alias)
if value is None:
if field.required:
errors.append(get_missing_field_error(loc=loc))
else:
values[field.name] = deepcopy(field.default)
continue
v_, errors_ = field.validate(value, values, loc=loc)
if isinstance(errors_, ErrorWrapper):
errors.append(errors_)
elif isinstance(errors_, list):
new_errors = _regenerate_error_with_loc(errors=errors_, loc_prefix=())
errors.extend(new_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[Dict[str, Any]]]:
values = {}
errors: List[Dict[str, Any]] = []
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 (is_sequence_field(field)) 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 is_sequence_field(field)
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 is_bytes_field(field)
and isinstance(value, UploadFile)
):
value = await value.read()
elif (
is_bytes_sequence_field(field)
and isinstance(field_info, params.File)
and value_is_sequence(value)
):
# For types
assert isinstance(value, sequence_types) # type: ignore[arg-type]
results: List[Union[bytes, str]] = []
async def process_fn(
fn: Callable[[], Coroutine[Any, Any, Any]]
) -> None:
result = await fn()
results.append(result) # noqa: B023
async with anyio.create_task_group() as tg:
for sub_value in value:
tg.start_soon(process_fn, sub_value.read)
value = serialize_sequence_value(field=field, value=results)
v_, errors_ = field.validate(value, values, loc=loc)
if isinstance(errors_, list):
errors.extend(errors_)
elif errors_:
errors.append(errors_)
else:
values[field.name] = v_
return values, errors
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:
check_file_field(first_param)
return first_param
# 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) # noqa: B010
model_name = "Body_" + name
BodyModel = create_body_model(
fields=flat_dependant.body_params, model_name=model_name
)
required = any(True for f in flat_dependant.body_params if f.required)
BodyFieldInfo_kwargs: Dict[str, Any] = {
"annotation": BodyModel,
"alias": "body",
}
if not required:
BodyFieldInfo_kwargs["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 = [
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