Should check nested functions

[PeterJCLaw]

python: 3.5.2, 3.6.5
pyre: 0.0.7 (from pip list)

Given a file thing.py:

def outer() -> str:
    def inner(x: int, y: str) -> str:
        return x
    return inner(42, None)

outer()

# Copy of 'inner' to prove that it errors at the top level
def outer_inner(x: int, y: str) -> str:
    return x

outer_inner(42, None)

I'd expect to get errors from the bad types in the nested inner function. For reference, here's what mypy (0.600) outputs:

$ mypy thing.py 
thing.py:3: error: Incompatible return value type (got "int", expected "str")
thing.py:4: error: Argument 2 to "inner" has incompatible type "None"; expected "str"
thing.py:10: error: Incompatible return value type (got "int", expected "str")
thing.py:12: error: Argument 2 to "outer_inner" has incompatible type "None"; expected "str"

Yet while pyre does not find errors in the top level equivalent function outer_inner, it doesn't emit any errors about the nested function:

$ pyre check
 ƛ Found 1 type error!
thing.py:2:4 Incompatible return type [7]: Expected `str` but got `int`.

[dark]

Hi @PeterJCLaw, thanks for the report.
We are aware of this limitation, and adding support to type-check nested functions is in our todo list.

[PeterJCLaw]

@dark Thanks! Is there a list of known limitations somewhere, to save us reporting (and you having to triage) known limitations?

[dark]

Unfortunately we don't have such a list in the repo. We should add one.

[dark]

This feature has been implemented a while ago, I had forgot to ping this task. The example above now triggers errors on all relevant lines.

[PeterJCLaw]

Nice, thanks for fixing 😊