mypy error on progress bar usage

[decaz]

xxx.py:

import click

with click.progressbar([1, 2, 3]) as bar:
    for x in bar:
        pass

mypy error:

$ mypy xxx.py 
xxx.py:4: error: "Iterable[<nothing>]" has no attribute "__next__"  [attr-defined]
Found 1 error in 1 file (checked 1 source file)

Environment:

• Python version: 3.9.5
• Click version: 8.0.0
• mypy version: 0.812

[jcrotts]

Changing the return type in ProgressBar.__iter__

click/src/click/_termui_impl.py

Line 104 in 9da1669

def __iter__(self) -> t.Iterable[V]:

from t.Iterable[V] to t.Iterator[V] fixes the mypy error, but it requires that you declare the type of x.
I'm also not sure if it's the correct thing to do type wise.

[davidism]

I'm working in this, going to use generics since it shouldn't affect performance in this case