3.11 StrEnum members are reduced to str in some cases

[layday]

Describe the bug
This is the most peculiar set of preconditions, but if all of the following are true:

• If click is installed and
• if a function within a package is decorated with click.group or click.command and
• if the function is imported in the package's __main__ module and
• if the function is called

... then StrEnum members are reduced down to simple strs.

I was not able to repro this if I renamed __main__, or if I used a locally-defined decorator, or if I did not call the function, or if I constructed a custom StrEnum by subclassing str and Enum.

To Reproduce

1. (Optionally?) install Python 3.11.0rc2
2. Clone https://github.com/layday/pyright-311-strenum-repro
3. Ensure click is installed
4. Type check the pkg with npx -y pyright --pythonversion 3.11

The output is:

No configuration file found.
No pyproject.toml file found.
stubPath /[...]/typings is not a valid directory.
Assuming Python platform Darwin
Searching for source files
Auto-excluding /[...]/venv
Found 2 source files
pyright 1.1.273
/[...]/pkg/module1.py
  /[...]/pkg/module1.py:17:13 - information: Type of "Foo.bar" is "str"
  /[...]/pkg/module1.py:18:13 - information: Type of "some_foos" is "set[str]"
0 errors, 0 warnings, 2 informations

Expected behavior
That Foo.bar would be of type Foo and some_foos of type set[Foo].

VS Code extension or command-line
CLI, 1.1.273

[erictraut]

Thanks for the bug report and clear repro. This will be addressed in the next release.

[erictraut]

This is addressed in pyright 1.1.274, which I just published. It will also be included in a future release of pylance.

[layday]

@erictraut I believe this has resurfaced in v1.1.290:

No configuration file found.
No pyproject.toml file found.
stubPath /[...]/typings is not a valid directory.
Assuming Python platform Darwin
Searching for source files
Found 2 source files
pyright 1.1.290
/[...]/pkg/module1.py
  /[...]/pkg/module1.py:18:13 - information: Type of "Foo.bar" is "str"
  /[...]/pkg/module1.py:19:13 - information: Type of "some_foos" is "set[str]"
0 errors, 0 warnings, 2 informations
Completed in 1.078sec

[erictraut]

Same repro steps as above? If the repro steps are different, please open a new issue. If they're the same, I'll reopen this one.

[layday]

They are the same.

[erictraut]

Yes, this was a regression introduced in another recent bug fix. Normally our tests prevent such regressions, but I haven't been able to repro this bug under conditions of our test suite. It's extremely dependent on the order in which evaluation occurs, and any small change in the ordering makes the problem go away.

The underlying problem is caused by a circular dependency in the way that StrEnum is declared. It derives from ReprEnum which derives from Enum which is based on the metaclass EnumMeta which has a __new__ method that accepts an argument of type FlagBoundary which itself derives from StrEnum.

I've made our circular dependency detection logic more robust to accommodate this case. This will be included in the next release.

[layday]

Thank you for the detailed explanation.

[erictraut]

This is included in pyright 1.1.291, which I just published. It will also be included in a future release of pylance.