Pyright: spurious unbound error for complicated closure

[christopher-hesse]

Describe the bug

There looks to be a spurious unbound error when doing some stuff with a complicated closure. I'm not sure if this is a typeshed issue or what, since the error will disappear if the code changes too much.

To Reproduce

from typing import Callable


def perform_request(build_req: Callable[[], str]) -> str:
    return "purr"


def make_api_request(auth: str) -> str:
    return "meow"


def testfunc() -> None:
    resp = open("test")
    auth = resp.read()

    def build_req():
        # switching out this line makes the error go away
        # def build_req() -> str:
        return make_api_request(auth=auth)

    resp = perform_request(build_req)

pyright --project misc\pyright_test\pyright_test20
Loading configuration file at c:\p\misc\pyright_test\pyright_test20\pyrightconfig.json
typingsPath c:\p\misc\pyright_test\pyright_test20\typings is not a valid directory.
Searching for source files
Found 1 source file
c:\p\misc\pyright_test\pyright_test20\test.py
  38:38 - error: 'auth' is unbound
1 error, 0 warnings
Completed in 1.246sec

Expected behavior

This code is a little suspicious (assigning a different type to resp for instance), but it seems likely that the error printed is not the correct one.

VS Code extension or command-line

pyright --version
pyright 1.1.8

[christopher-hesse]

mypy calls out the missing annotation as well as the overwritten value of resp:

mypy --strict misc\pyright_test\pyright_test20\test.py 
misc\pyright_test\pyright_test20\test.py:36: error: Function is missing a type annotation
misc\pyright_test\pyright_test20\test.py:41: error: Incompatible types in assignment (expression has type "str", variable has type "TextIO")

[erictraut]

Thanks for reporting the bug. This will be fixed in the next version. I've also added your sample as a unit test to prevent regressions in the future.

[erictraut]

This is now implemented in version 1.1.9, which I just published.