stubgen: Allow aliases below the top level

[chadrik]

(Explain how this PR changes mypy.)

stubgen currently allows a variable to be an alias to another, but only at the module level.

For example:

def func() -> int:
    return 2

aliased_func = func

class Foo:
    def meth() -> int:
        return 2
    
    aliased_meth = meth

produces:

def func() -> int: ...
aliased_func = func

class Foo:
    def meth() -> int: ...
    aliased_meth: Incomplete   # <--- should be  `aliased_meth = meth`

At the class level, these aliased variables are marked as Incomplete.

In my experience, enabling aliases below the top level produces better stubs.

I'm not sure what the original reservations were around use of these aliases. If the concerns about class-level aliases are still valid, I can add an option to enable them.

[chadrik]

@hauntsaninja do you mind giving this a review?

[chadrik]

Anyone have a minute for this PR?

[hauntsaninja]

Thanks, this looks reasonable.

Can we just make this the default and not have it be configurable? Could you also add some assignment statements inside methods in the test case to prove that they don't get included.

[chadrik]

Can we just make this the default and not have it be configurable?

I was inclined to do that, but I don't know why it was specifically limited to module aliases in the first place. I can't see the scenario where that's preferable. I'm happy to delegate that decision to you or anyone else in the mypy crew.

Could you also add some assignment statements inside methods in the test case to prove that they don't get included.

sure.

[hauntsaninja]

Let's make it the default

[chadrik]

I backed out the commit that added the cli arg, and added a function level alias to the test. waiting for CI tests to pass.

[chadrik]

ready to go!

[hauntsaninja]

Thanks!