Pylance should be able to recognize docstrings for type aliases

[macintacos]

I can't seem to get VSCode to recognize docstrings for type aliases that I define. Say I have the following type alias and docstring:

SomeType = List[Union[dict, str]]
"""Here's some documentation about SomeType"""

For an example of how I'd like it to work, Pycharm shows the following when I hover over SomeType:

In VSCode I only seem to see documentation related to the underlying types instead of the documentation I provided for the alias:

In an ideal world, I'd be able to see both the underlying type documentation and the documentation that I added for the alias myself, but honestly I'd settle for at least always showing the documentation that I specified in the project itself.

Can this be added? This felt like something that should be implemented in Pylance, but I wasn't 100% sure - please feel free to move it to whatever project makes the most sense!

[jakebailey]

Interesting; this should have worked as we explicitly intend to support these types of docstrings (see #1576).

This may be something specific to aliases.

[erictraut]

We do support variable doc strings, but type aliases are distinct from other types of variables. It should be feasible to extend the support for type aliases.

[jakebailey]

Yep, it's a small change (I'm making it now).

[jakebailey]

In this case, it's hitting the fact that it's an instantiable type before it hits the code that checks if it's a variable.

[jakebailey]

This will be fixed in the next release.

[macintacos]

That's great, thanks!

[jakebailey]

This issue has been fixed in version 2021.9.2, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md#202192-16-september-2021