Please check our new types!

[A5rocks]

trio now has some level of typed-ness! Unfortunately, we did not just copy over trio-typing meaning the type hints are slightly different.

If your project:

1. uses trio-typing or some custom type stubs (!?!)
2. is typechecked against a recent trio version

then please help us check our new typed interface by checking your code against git+https://github.com/python-trio/trio and telling us your results here! I expect a couple minor-ish typing changes before releasing 0.23.0 (TypeVarTuples, #2761, and fixes for any type issues) but the current state of things should be final-ish.

[agronholm]

I ran this against AnyIO and got 7 errors about unused type: ignore comments 👍

[A5rocks]

Checking against tricycle, it just looks like over-adaptation to trio-typing AND that _NurseryStartFunc isn't typed correctly:

(venv) PS C:\Users\A5rocks\Documents\Temp\tricycle> mypy --strict --implicit-reexport -p tricycle
tricycle\_service_nursery.py:4: error: Cannot find implementation or library stub for module named "trio_typing"  [import]
tricycle\_service_nursery.py:4: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
tricycle\_service_nursery.py:121: error: Unused "type: ignore" comment
tricycle\_service_nursery.py:128: error: Unused "type: ignore" comment
tricycle\_service_nursery.py:132: error: Argument 2 to "start" of "Nursery" has incompatible type "Callable[[NamedArg(Any, 'task_status')], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[Any]"  [arg-type]
tricycle\_tests\test_tree_var.py:5: error: Cannot find implementation or library stub for module named "trio_typing"  [import]
tricycle\_tests\test_tree_var.py:96: error: Need type annotation for "target_nursery"  [var-annotated]
tricycle\_tests\test_tree_var.py:96: error: Argument 1 to "start" of "Nursery" has incompatible type "Callable[[Any], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[<nothing>]"  [arg-type]
tricycle\_tests\test_tree_var.py:100: error: Argument 1 to "start" of "Nursery" has incompatible type "Callable[[str, DefaultNamedArg(Any, 'task_status')], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[<nothing>]"  [arg-type]

(this is just the start of the output)

[jakkdl]

Checking against tricycle, it just looks like over-adaptation to trio-typing AND that _NurseryStartFunc isn't typed correctly:

(venv) PS C:\Users\A5rocks\Documents\Temp\tricycle> mypy --strict --implicit-reexport -p tricycle
tricycle\_service_nursery.py:4: error: Cannot find implementation or library stub for module named "trio_typing"  [import]
tricycle\_service_nursery.py:4: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
tricycle\_service_nursery.py:121: error: Unused "type: ignore" comment
tricycle\_service_nursery.py:128: error: Unused "type: ignore" comment
tricycle\_service_nursery.py:132: error: Argument 2 to "start" of "Nursery" has incompatible type "Callable[[NamedArg(Any, 'task_status')], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[Any]"  [arg-type]
tricycle\_tests\test_tree_var.py:5: error: Cannot find implementation or library stub for module named "trio_typing"  [import]
tricycle\_tests\test_tree_var.py:96: error: Need type annotation for "target_nursery"  [var-annotated]
tricycle\_tests\test_tree_var.py:96: error: Argument 1 to "start" of "Nursery" has incompatible type "Callable[[Any], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[<nothing>]"  [arg-type]
tricycle\_tests\test_tree_var.py:100: error: Argument 1 to "start" of "Nursery" has incompatible type "Callable[[str, DefaultNamedArg(Any, 'task_status')], Coroutine[Any, Any, None]]"; expected "_NurseryStartFunc[<nothing>]"  [arg-type]

(this is just the start of the output)

Ah no, that's an incorrect type hint that's getting fixed in #2773 (comment)

[apollo13]

I am running with pyright and it shows this error:

error: Object of type "Lock" cannot be used with "with" because it does not implement __aenter__ (reportGeneralTypeIssues)
error: Object of type "Lock" cannot be used with "with" because it does not implement __aexit__ (reportGeneralTypeIssues)

for this code (trio from master as of now):

import trio


async def test():
    async with trio.Lock():
        print("HI")


trio.run(test)

[A5rocks]

My first guess is that pyright doesn't support the self-type pattern we use in trio/_sync for async with, added in e97bcb6

If someone could confirm this with a small reproduction and make an issue on pyright's repository, I believe that will be fixed quickly.

EDIT: actually, no longer sure cause I couldn't make a simple reproduction of what I thought the bug was. I'll check this out later.

[apollo13]

This is going way over my head. I played around a bit with it and replaced AsyncContextManagerMixin with the following:

class AsyncContextManagerMixin:
    #@enable_ki_protection
    async def __aenter__(self: _HasAcquireRelease) -> None:
        await self.acquire()
    __aenter__ = enable_ki_protection(__aenter__)

    #@enable_ki_protection
    async def __aexit__(
        self: _HasAcquireRelease,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        traceback: TracebackType | None,
    ) -> None:
        self.release()
    __aexit__ = enable_ki_protection(__aexit__)        

so essentially I replaced @enable_ki_protection with __aexit__ = enable_ki_protection(__aexit__). Which should be equivalent?

Now pyright complains:

Could not bind method "__aenter__" because "Lock" is not assignable to parameter "self"
  "Lock" is incompatible with protocol "_HasAcquireRelease"
    "acquire" is an incompatible type
      Type "(**ArgsT) -> RetT" cannot be assigned to type "() -> Coroutine[Any, Any, object]"
        Function return type "RetT" is incompatible with type "Coroutine[Any, Any, object]"
          "object*" is incompatible with "Coroutine[Any, Any, object]"
Could not bind method "__aexit__" because "Lock" is not assignable to parameter "self"
  "Lock" is incompatible with protocol "_HasAcquireRelease"
    "acquire" is an incompatible type
      Type "(**ArgsT) -> RetT" cannot be assigned to type "() -> Coroutine[Any, Any, object]"
        Function return type "RetT" is incompatible with type "Coroutine[Any, Any, object]"
          "object*" is incompatible with "Coroutine[Any, Any, object]"

[agronholm]

Why is self even annotated here?

[apollo13]

According to the doc-string of _HasAcquireRelease to prevent misusing it (though I guess that goes a bit over the top):

class _HasAcquireRelease(Protocol):
    """Only classes with acquire() and release() can use the mixin's implementations."""

    async def acquire(self) -> object:
        ...

    def release(self) -> object:
        ...

[agronholm]

I'm very uncomfortable with the amount of "defensive" code in Trio.

[GalaxySnail]

The py.typed file is missing in wheels, I have created a pull request to fix it: #2780.

[A5rocks]

Why is self even annotated here?

Either we could annotate it like so or we could add type ignores (what we had before); might as well be type safe as this should be guaranteed to work (and if it doesn't that's indicative of a type checker bug somewhere).

I'm not sure why pyright is erroring though -- it looks like it's wrong about the Lock.acquire's value.