Update mypy to 0.950 and fix complaints

changelog.d/12650.misc

@@ -0,0 +1 @@
+Update to mypy 0.950.

pyproject.toml

@@ -248,8 +248,8 @@ flake8-bugbear = "==21.3.2"
 flake8 = "*"
 
 # Typechecking
-mypy = "==0.931"
-mypy-zope = "==0.3.5"
+mypy = "*"
+mypy-zope = "*"
 types-bleach = ">=4.1.0"
 types-commonmark = ">=0.9.2"
 types-jsonschema = ">=3.2.0"

stubs/sortedcontainers/sorteddict.pyi

@@ -85,12 +85,19 @@ class SortedDict(Dict[_KT, _VT]):
  def popitem(self, index: int = ...) -> Tuple[_KT, _VT]: ...
  def peekitem(self, index: int = ...) -> Tuple[_KT, _VT]: ...
  def setdefault(self, key: _KT, default: Optional[_VT] = ...) -> _VT: ...
- @overload
- def update(self, __map: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
- @overload
- def update(self, __iterable: Iterable[Tuple[_KT, _VT]], **kwargs: _VT) -> None: ...
- @overload
- def update(self, **kwargs: _VT) -> None: ...
+ # Mypy now reports the first overload as an error, because typeshed widened the type
+ # of `__map` to its internal `_typeshed.SupportsKeysAndGetItem` type in
+ # https://github.com/python/typeshed/pull/6653
+ # Since sorteddicts don't change the signature of `update` from that of `dict`, we
+ # let the stubs for `update` inherit from the stubs for `dict`. (I suspect we could
+ # do the same for many othe methods.) We leave the stubs commented to better track
+ # how this file has evolved from the original stubs.
+ # @overload
+ # def update(self, __map: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
+ # @overload
+ # def update(self, __iterable: Iterable[Tuple[_KT, _VT]], **kwargs: _VT) -> None: ...
+ # @overload
+ # def update(self, **kwargs: _VT) -> None: ...
  def __reduce__(
  self,
  ) -> Tuple[

synapse/appservice/api.py

@@ -17,6 +17,7 @@
 from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Tuple
 
 from prometheus_client import Counter
+from typing_extensions import TypeGuard
 
 from synapse.api.constants import EventTypes, Membership, ThirdPartyEntityKind
 from synapse.api.errors import CodeMessageException
@@ -66,7 +67,7 @@ def _is_valid_3pe_metadata(info: JsonDict) -> bool:
  return True
 
 
-def _is_valid_3pe_result(r: JsonDict, field: str) -> bool:
+def _is_valid_3pe_result(r: object, field: str) -> TypeGuard[JsonDict]:
  if not isinstance(r, dict):
  return False
 

synapse/config/appservice.py

@@ -56,7 +56,8 @@ def load_appservices(
 ) -> List[ApplicationService]:
  """Returns a list of Application Services from the config files."""
  if not isinstance(config_files, list):
- logger.warning("Expected %s to be a list of AS config files.", config_files)
+ # type-ignore: this function gets arbitrary json value; we do use this path.
+ logger.warning("Expected %s to be a list of AS config files.", config_files) # type: ignore[unreachable]
  return []
 
  # Dicts of value -> filename

synapse/events/presence_router.py

@@ -147,7 +147,9 @@ async def get_users_for_states(
  # run all the callbacks for get_users_for_states and combine the results
  for callback in self._get_users_for_states_callbacks:
  try:
- result = await callback(state_updates)
+ # Note: result is an object here, because we don't trust modules to
+ # return the types they're supposed to.
+ result: object = await callback(state_updates)
  except Exception as e:
  logger.warning("Failed to run module API callback %s: %s", callback, e)
  continue

synapse/handlers/message.py

@@ -1427,7 +1427,7 @@ async def persist_and_notify_client_event(
  # Validate a newly added alias or newly added alt_aliases.
 
  original_alias = None
- original_alt_aliases: List[str] = []
+ original_alt_aliases: object = []
 
  original_event_id = event.unsigned.get("replaces_state")
  if original_event_id:
@@ -1455,6 +1455,7 @@ async def persist_and_notify_client_event(
  # If the old version of alt_aliases is of an unknown form,
  # completely replace it.
  if not isinstance(original_alt_aliases, (list, tuple)):
+ # TODO: check that the original_alt_aliases' entries are all strings
  original_alt_aliases = []
 
  # Check that each alias is currently valid.

synapse/metrics/background_process_metrics.py

@@ -28,11 +28,11 @@
  Type,
  TypeVar,
  Union,
- cast,
 )
 
 from prometheus_client import Metric
 from prometheus_client.core import REGISTRY, Counter, Gauge
+from typing_extensions import ParamSpec
 
 from twisted.internet import defer
 
@@ -256,24 +256,48 @@ async def run() -> Optional[R]:
  return defer.ensureDeferred(run())
 
 
-F = TypeVar("F", bound=Callable[..., Awaitable[Optional[Any]]])
+P = ParamSpec("P")
 
 
-def wrap_as_background_process(desc: str) -> Callable[[F], F]:
- """Decorator that wraps a function that gets called as a background
- process.
+def wrap_as_background_process(
+ desc: str,
+) -> Callable[
+ [Callable[P, Awaitable[Optional[R]]]],
+ Callable[P, "defer.Deferred[Optional[R]]"],
+]:
+ """Decorator that wraps an asynchronous function `func`, returning a synchronous
+ decorated function. Calling the decorated version runs `func` as a background
+ process, forwarding all arguments verbatim.
+
+ That is,
+
+ @wrap_as_background_process
+ def func(*args): ...
+ func(1, 2, third=3)
+
+ is equivalent to:
+
+ def func(*args): ...
+ run_as_background_process(func, 1, 2, third=3)
 
- Equivalent to calling the function with `run_as_background_process`
+ The former can be convenient if `func` needs to be run as a background process in
+ multiple places.
  """
 
- def wrap_as_background_process_inner(func: F) -> F:
+ def wrap_as_background_process_inner(
+ func: Callable[P, Awaitable[Optional[R]]]
+ ) -> Callable[P, "defer.Deferred[Optional[R]]"]:
  @wraps(func)
  def wrap_as_background_process_inner_2(
- *args: Any, **kwargs: Any
+ *args: P.args, **kwargs: P.kwargs
  ) -> "defer.Deferred[Optional[R]]":
- return run_as_background_process(desc, func, *args, **kwargs)
+ # type-ignore: mypy is confusing kwargs with the bg_start_span kwarg.
+ # Argument 4 to "run_as_background_process" has incompatible type
+ # "**P.kwargs"; expected "bool"
+ # See https://github.com/python/mypy/issues/8862
+ return run_as_background_process(desc, func, *args, **kwargs) # type: ignore[arg-type]
 
- return cast(F, wrap_as_background_process_inner_2)
+ return wrap_as_background_process_inner_2
 
  return wrap_as_background_process_inner
 

tests/storage/test_monthly_active_users.py

@@ -222,19 +222,19 @@ def test_reap_monthly_active_users_reserved_users(self):
  self.store.user_add_threepid(user, "email", email, now, now)
  )
 
- d = self.store.db_pool.runInteraction(
- "initialise", self.store._initialise_reserved_users, threepids
+ self.get_success(
+ self.store.db_pool.runInteraction(
+ "initialise", self.store._initialise_reserved_users, threepids
+ )
  )
- self.get_success(d)
 
  count = self.get_success(self.store.get_monthly_active_count())
  self.assertEqual(count, initial_users)
 
  users = self.get_success(self.store.get_registered_reserved_users())
  self.assertEqual(len(users), reserved_user_number)
 
- d = self.store.reap_monthly_active_users()
- self.get_success(d)
+ self.get_success(self.store.reap_monthly_active_users())
 
  count = self.get_success(self.store.get_monthly_active_count())
  self.assertEqual(count, self.hs.config.server.max_mau_value)