Enforce strict mypy checks

.mypy.ini

@@ -0,0 +1,24 @@
+[mypy]
+warn_unused_configs = True
+strict = True
+
+[mypy-aiodns]
+ignore_missing_imports = True
+
+[mypy-brotli]
+ignore_missing_imports = True
+
+[mypy-gunicorn.*]
+ignore_missing_imports = True
+
+[mypy-uvloop]
+ignore_missing_imports = True
+
+[mypy-cchardet]
+ignore_missing_imports = True
+
+[mypy-tokio]
+ignore_missing_imports = True
+
+[mypy-asynctest]
+ignore_missing_imports = True

CHANGES/3927.misc

@@ -0,0 +1 @@
+Use ``mypy --strict``

Makefile

@@ -74,7 +74,7 @@ fmt format:
 
 .PHONY: mypy
 mypy:
-	mypy aiohttp tests
+	mypy --show-error-codes aiohttp tests
 
 .develop: .install-deps $(call to-hash,$(PYS) $(CYS) $(CS))
 	pip install -e .

aiohttp/client.py

@@ -27,6 +27,7 @@
     Type,
     TypeVar,
     Union,
+    cast,
 )
 
 from multidict import CIMultiDict, MultiDict, MultiDictProxy, istr
@@ -133,7 +134,7 @@
 try:
     from ssl import SSLContext
 except ImportError:  # pragma: no cover
-    SSLContext = object  # type: ignore
+    SSLContext = object  # type: ignore[assignment,misc]
 
 
 @dataclasses.dataclass(frozen=True)
@@ -245,10 +246,10 @@ def __init__(
         self._default_auth = auth
         self._version = version
         self._json_serialize = json_serialize
-        if timeout is sentinel:
-            self._timeout = DEFAULT_TIMEOUT
+        if isinstance(timeout, ClientTimeout):
+            self._timeout = timeout
         else:
-            self._timeout = timeout  # type: ignore
+            self._timeout = DEFAULT_TIMEOUT
         self._raise_for_status = raise_for_status
         self._auto_decompress = auto_decompress
         self._trust_env = trust_env
@@ -378,10 +379,10 @@ async def _request(
                 raise InvalidURL(proxy) from e
 
         if timeout is sentinel:
-            real_timeout = self._timeout  # type: ClientTimeout
+            real_timeout: ClientTimeout = self._timeout
         else:
             if not isinstance(timeout, ClientTimeout):
-                real_timeout = ClientTimeout(total=timeout)  # type: ignore
+                real_timeout = ClientTimeout(total=cast(float, timeout))
             else:
                 real_timeout = timeout
         # timeout is cumulative for all request operations
@@ -690,7 +691,7 @@ async def _ws_connect(
                     DeprecationWarning,
                     stacklevel=2,
                 )
-                ws_timeout = ClientWSTimeout(ws_close=timeout)  # type: ignore
+                ws_timeout = ClientWSTimeout(ws_close=cast(float, timeout))
         else:
             ws_timeout = DEFAULT_WS_CLIENT_TIMEOUT
         if receive_timeout is not None:
@@ -1053,7 +1054,7 @@ def __init__(self, coro: Coroutine["asyncio.Future[Any]", None, _RetType]) -> No
     def send(self, arg: None) -> "asyncio.Future[Any]":
         return self._coro.send(arg)
 
-    def throw(self, arg: BaseException) -> None:  # type: ignore
+    def throw(self, arg: BaseException) -> None:  # type: ignore[override]
         self._coro.throw(arg)
 
     def close(self) -> None:

aiohttp/client_exceptions.py

@@ -11,7 +11,7 @@
 
     SSLContext = ssl.SSLContext
 except ImportError:  # pragma: no cover
-    ssl = SSLContext = None  # type: ignore
+    ssl = SSLContext = None  # type: ignore[assignment]
 
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -270,11 +270,11 @@ class ClientSSLError(ClientConnectorError):
     ssl_error_bases = (ClientSSLError,)
 
 
-class ClientConnectorSSLError(*ssl_error_bases):  # type: ignore
+class ClientConnectorSSLError(*ssl_error_bases):  # type: ignore[misc]
     """Response ssl error."""
 
 
-class ClientConnectorCertificateError(*cert_errors_bases):  # type: ignore
+class ClientConnectorCertificateError(*cert_errors_bases):  # type: ignore[misc]
     """Response certificate error."""
 
     def __init__(

aiohttp/client_reqrep.py

@@ -64,13 +64,13 @@
     import ssl
     from ssl import SSLContext
 except ImportError:  # pragma: no cover
-    ssl = None  # type: ignore
-    SSLContext = object  # type: ignore
+    ssl = None  # type: ignore[assignment]
+    SSLContext = object  # type: ignore[assignment,misc]
 
 try:
     import cchardet as chardet
 except ImportError:  # pragma: no cover
-    import chardet  # type: ignore
+    import chardet  # type: ignore[no-redef]
 
 
 __all__ = ("ClientRequest", "ClientResponse", "RequestInfo", "Fingerprint")
@@ -333,9 +333,9 @@ def update_headers(self, headers: Optional[LooseHeaders]) -> None:
 
         if headers:
             if isinstance(headers, (dict, MultiDictProxy, MultiDict)):
-                headers = headers.items()  # type: ignore
+                headers = headers.items()  # type: ignore[assignment]
 
-            for key, value in headers:  # type: ignore
+            for key, value in headers:  # type: ignore[misc]
                 # A special case for Host header
                 if key.lower() == "host":
                     self.headers[key] = value
@@ -347,7 +347,7 @@ def update_auto_headers(self, skip_auto_headers: Iterable[str]) -> None:
             (hdr, None) for hdr in sorted(skip_auto_headers)
         )
         used_headers = self.headers.copy()
-        used_headers.extend(self.skip_auto_headers)  # type: ignore
+        used_headers.extend(self.skip_auto_headers)  # type: ignore[arg-type]
 
         for hdr, val in self.DEFAULT_HEADERS.items():
             if hdr not in used_headers:
@@ -369,15 +369,15 @@ def update_cookies(self, cookies: Optional[LooseCookies]) -> None:
         if isinstance(cookies, Mapping):
             iter_cookies = cookies.items()
         else:
-            iter_cookies = cookies  # type: ignore
+            iter_cookies = cookies  # type: ignore[assignment]
         for name, value in iter_cookies:
             if isinstance(value, Morsel):
                 # Preserve coded_value
                 mrsl_val = value.get(value.key, Morsel())
                 mrsl_val.set(value.key, value.value, value.coded_value)
                 c[name] = mrsl_val
             else:
-                c[name] = value  # type: ignore
+                c[name] = value  # type: ignore[assignment]
 
         self.headers[hdrs.COOKIE] = c.output(header="", sep=";").strip()
 
@@ -519,10 +519,12 @@ async def write_bytes(
                 await self.body.write(writer)
             else:
                 if isinstance(self.body, (bytes, bytearray)):
-                    self.body = (self.body,)  # type: ignore
+                    body = (self.body,)
+                else:
+                    body = self.body
 
-                for chunk in self.body:
-                    await writer.write(chunk)  # type: ignore
+                for chunk in body:
+                    await writer.write(chunk)
 
             await writer.write_eof()
         except OSError as exc:
@@ -806,7 +808,7 @@ def links(self) -> "MultiDictProxy[MultiDictProxy[Union[str, URL]]]":
 
                 link.add(key, value)
 
-            key = link.get("rel", url)  # type: ignore
+            key = link.get("rel", url)  # type: ignore[assignment]
 
             link.add("url", self.url.join(URL(url)))
 
@@ -818,13 +820,14 @@ async def start(self, connection: "Connection") -> "ClientResponse":
         """Start response processing."""
         self._closed = False
         self._protocol = connection.protocol
+        assert self._protocol is not None
         self._connection = connection
 
         with self._timer:
             while True:
                 # read response
                 try:
-                    message, payload = await self._protocol.read()  # type: ignore
+                    message, payload = await self._protocol.read()
                 except http.HttpProcessingError as exc:
                     raise ClientResponseError(
                         self.request_info,
@@ -1007,11 +1010,12 @@ async def text(self, encoding: Optional[str] = None, errors: str = "strict") ->
         """Read response payload and decode."""
         if self._body is None:
             await self.read()
+            assert self._body is not None
 
         if encoding is None:
             encoding = self.get_encoding()
 
-        return self._body.decode(encoding, errors=errors)  # type: ignore
+        return self._body.decode(encoding, errors=errors)
 
     async def json(
         self,
@@ -1023,6 +1027,7 @@ async def json(
         """Read and decodes JSON response."""
         if self._body is None:
             await self.read()
+            assert self._body is not None
 
         if content_type:
             ctype = self.headers.get(hdrs.CONTENT_TYPE, "").lower()
@@ -1039,7 +1044,7 @@ async def json(
         if encoding is None:
             encoding = self.get_encoding()
 
-        return loads(self._body.decode(encoding))  # type: ignore
+        return loads(self._body.decode(encoding))
 
     async def __aenter__(self) -> "ClientResponse":
         return self

aiohttp/client_ws.py

@@ -2,7 +2,7 @@
 
 import asyncio
 import dataclasses
-from typing import Any, Optional
+from typing import Any, Optional, cast
 
 import async_timeout
 from typing_extensions import Final
@@ -68,10 +68,10 @@ def __init__(
         self._autoclose = autoclose
         self._autoping = autoping
         self._heartbeat = heartbeat
-        self._heartbeat_cb = None
+        self._heartbeat_cb: Optional[asyncio.TimerHandle] = None
         if heartbeat is not None:
             self._pong_heartbeat = heartbeat / 2.0
-        self._pong_response_cb = None
+        self._pong_response_cb: Optional[asyncio.TimerHandle] = None
         self._loop = loop
         self._waiting = None  # type: Optional[asyncio.Future[bool]]
         self._exception = None  # type: Optional[BaseException]
@@ -286,13 +286,13 @@ async def receive_str(self, *, timeout: Optional[float] = None) -> str:
         msg = await self.receive(timeout)
         if msg.type != WSMsgType.TEXT:
             raise TypeError(f"Received message {msg.type}:{msg.data!r} is not str")
-        return msg.data
+        return cast(str, msg.data)
 
     async def receive_bytes(self, *, timeout: Optional[float] = None) -> bytes:
         msg = await self.receive(timeout)
         if msg.type != WSMsgType.BINARY:
             raise TypeError(f"Received message {msg.type}:{msg.data!r} is not bytes")
-        return msg.data
+        return cast(bytes, msg.data)
 
     async def receive_json(
         self,

aiohttp/connector.py

@@ -55,8 +55,8 @@
 
     SSLContext = ssl.SSLContext
 except ImportError:  # pragma: no cover
-    ssl = None  # type: ignore
-    SSLContext = object  # type: ignore
+    ssl = None  # type: ignore[assignment]
+    SSLContext = object  # type: ignore[assignment,misc]
 
 
 __all__ = ("BaseConnector", "TCPConnector", "UnixConnector", "NamedPipeConnector")
@@ -218,18 +218,18 @@ def __init__(
         self._force_close = force_close
 
         # {host_key: FIFO list of waiters}
-        self._waiters = defaultdict(deque)  # type: ignore
+        self._waiters = defaultdict(deque)  # type: ignore[var-annotated]
 
         self._loop = loop
         self._factory = functools.partial(ResponseHandler, loop=loop)
 
         self.cookies = SimpleCookie()  # type: SimpleCookie[str]
 
         # start keep-alive connection cleanup task
-        self._cleanup_handle = None
+        self._cleanup_handle: Optional[asyncio.TimerHandle] = None
 
         # start cleanup closed transports task
-        self._cleanup_closed_handle = None
+        self._cleanup_closed_handle: Optional[asyncio.TimerHandle] = None
         self._cleanup_closed_disabled = not enable_cleanup_closed
         self._cleanup_closed_transports = []  # type: List[Optional[asyncio.Transport]]
         self._cleanup_closed()
@@ -744,7 +744,7 @@ def __init__(
         self._ssl = ssl
         if resolver is None:
             resolver = DefaultResolver()
-        self._resolver = resolver
+        self._resolver: AbstractResolver = resolver
 
         self._use_dns_cache = use_dns_cache
         self._cached_hosts = _DNSCacheTable(ttl=ttl_dns_cache)
@@ -943,7 +943,12 @@ async def _wrap_create_connection(
     ) -> Tuple[asyncio.Transport, ResponseHandler]:
         try:
             async with ceil_timeout(timeout.sock_connect):
-                return await self._loop.create_connection(*args, **kwargs)  # type: ignore  # noqa
+                transport, handler = await self._loop.create_connection(*args, **kwargs)
+                return (
+                    cast(asyncio.Transport, transport),
+                    cast(ResponseHandler, handler),
+                )
+
         except cert_errors as exc:
             raise ClientConnectorCertificateError(req.connection_key, exc) from exc
         except ssl_errors as exc:
@@ -1031,7 +1036,7 @@ async def _create_proxy_connection(
     ) -> Tuple[asyncio.Transport, ResponseHandler]:
         headers = {}  # type: Dict[str, str]
         if req.proxy_headers is not None:
-            headers = req.proxy_headers  # type: ignore
+            headers = req.proxy_headers  # type: ignore[assignment]
         headers[hdrs.HOST] = req.headers[hdrs.HOST]
 
         url = req.proxy
@@ -1202,7 +1207,9 @@ def __init__(
             limit=limit,
             limit_per_host=limit_per_host,
         )
-        if not isinstance(self._loop, asyncio.ProactorEventLoop):  # type: ignore
+        if not isinstance(
+            self._loop, asyncio.ProactorEventLoop  # type: ignore[attr-defined]
+        ):
             raise RuntimeError(
                 "Named Pipes only available in proactor " "loop under windows"
             )
@@ -1218,7 +1225,7 @@ async def _create_connection(
     ) -> ResponseHandler:
         try:
             async with ceil_timeout(timeout.sock_connect):
-                _, proto = await self._loop.create_pipe_connection(  # type: ignore
+                _, proto = await self._loop.create_pipe_connection(  # type: ignore[attr-defined]  # noqa: E501
                     self._factory, self._path
                 )
                 # the drain is required so that the connection_made is called

aiohttp/cookiejar.py

@@ -147,7 +147,7 @@ def update_cookies(self, cookies: LooseCookies, response_url: URL = URL()) -> No
         for name, cookie in cookies:
             if not isinstance(cookie, Morsel):
                 tmp = SimpleCookie()  # type: SimpleCookie[str]
-                tmp[name] = cookie  # type: ignore
+                tmp[name] = cookie  # type: ignore[assignment]
                 cookie = tmp[name]
 
             domain = cookie["domain"]

aiohttp/formdata.py

@@ -92,14 +92,14 @@ def add_fields(self, *fields: Any) -> None:
 
             if isinstance(rec, io.IOBase):
                 k = guess_filename(rec, "unknown")
-                self.add_field(k, rec)  # type: ignore
+                self.add_field(k, rec)
 
             elif isinstance(rec, (MultiDictProxy, MultiDict)):
                 to_add.extend(rec.items())
 
             elif isinstance(rec, (list, tuple)) and len(rec) == 2:
                 k, fp = rec
-                self.add_field(k, fp)  # type: ignore
+                self.add_field(k, fp)
 
             else:
                 raise TypeError(