run no_implicit_optional

[AllSeeingEyeTolledEweSew]

mypy has recently disabled implicit Optional by default (so def f(x: int = None): is no longer allowed)

They created a tool, no_implicit_optional, to auto-modify code.

However, I found that since my app's tests use asgi-lifespan, I cannot just run the no_implicit_optional tool on my own code. Since mypy now defaults to implicit_optional = False, this results in wrong typing for asgi_lifespan.LifespanManager. mypy then complains about my own correct use of LifespanManager.

For now, I'm working around my use of LifespanManager with # type: ignore, but it would be nice to make asgi-lifespan use strict Optional.

Before:

$ mypy .
src/asgi_lifespan/_concurrency/trio.py:54: error: Incompatible return value type (got "Background", expected "AbstractAsyncContextManager[Any]")  [return-value]
src/asgi_lifespan/_concurrency/trio.py:54: note: Following member(s) of "Background" have conflicts:
src/asgi_lifespan/_concurrency/trio.py:54: note:     Expected:
src/asgi_lifespan/_concurrency/trio.py:54: note:         def __aexit__(self, Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType], /) -> Coroutine[Any, Any, Optional[bool]]
src/asgi_lifespan/_concurrency/trio.py:54: note:     Got:
src/asgi_lifespan/_concurrency/trio.py:54: note:         def __aexit__(self, exc_type: Optional[Type[BaseException]] = ..., exc_value: BaseException = ..., traceback: TracebackType = ...) -> Coroutine[Any, Any, None]
src/asgi_lifespan/_concurrency/trio.py:69: error: Incompatible default for argument "exc_value" (default has type "None", argument has type "BaseException")  [assignment]
src/asgi_lifespan/_concurrency/trio.py:69: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_concurrency/trio.py:69: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_concurrency/trio.py:70: error: Incompatible default for argument "traceback" (default has type "None", argument has type "TracebackType")  [assignment]
src/asgi_lifespan/_concurrency/trio.py:70: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_concurrency/trio.py:70: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_concurrency/asyncio.py:51: error: Incompatible return value type (got "Background", expected "AbstractAsyncContextManager[Any]")  [return-value]
src/asgi_lifespan/_concurrency/asyncio.py:51: note: Following member(s) of "Background" have conflicts:
src/asgi_lifespan/_concurrency/asyncio.py:51: note:     Expected:
src/asgi_lifespan/_concurrency/asyncio.py:51: note:         def __aexit__(self, Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType], /) -> Coroutine[Any, Any, Optional[bool]]
src/asgi_lifespan/_concurrency/asyncio.py:51: note:     Got:
src/asgi_lifespan/_concurrency/asyncio.py:51: note:         def __aexit__(self, exc_type: Optional[Type[BaseException]] = ..., exc_value: BaseException = ..., traceback: TracebackType = ...) -> Coroutine[Any, Any, None]
src/asgi_lifespan/_concurrency/asyncio.py:71: error: Incompatible default for argument "exc_value" (default has type "None", argument has type "BaseException")  [assignment]
src/asgi_lifespan/_concurrency/asyncio.py:71: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_concurrency/asyncio.py:71: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_concurrency/asyncio.py:72: error: Incompatible default for argument "traceback" (default has type "None", argument has type "TracebackType")  [assignment]
src/asgi_lifespan/_concurrency/asyncio.py:72: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_concurrency/asyncio.py:72: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_manager.py:97: error: Incompatible default for argument "exc_type" (default has type "None", argument has type "Type[BaseException]")  [assignment]
src/asgi_lifespan/_manager.py:97: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_manager.py:97: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_manager.py:98: error: Incompatible default for argument "exc_value" (default has type "None", argument has type "BaseException")  [assignment]
src/asgi_lifespan/_manager.py:98: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_manager.py:98: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase
src/asgi_lifespan/_manager.py:99: error: Incompatible default for argument "traceback" (default has type "None", argument has type "TracebackType")  [assignment]
src/asgi_lifespan/_manager.py:99: note: PEP 484 prohibits implicit Optional. Accordingly, mypy has changed its default to no_implicit_optional=True
src/asgi_lifespan/_manager.py:99: note: Use https://github.com/hauntsaninja/no_implicit_optional to automatically upgrade your codebase

I ran:

$ no_implicit_optional .
Calculating full-repo metadata...
Executing codemod...
Finished codemodding 15 files!
 - Transformed 15 files successfully.
 - Skipped 0 files.
 - Failed to codemod 0 files.
 - 0 warnings were generated.
$ isort  src/ tests/
Fixing /home/amnesia/Persistent/checkout/asgi-lifespan/src/asgi_lifespan/_manager.py
Fixing /home/amnesia/Persistent/checkout/asgi-lifespan/src/asgi_lifespan/_concurrency/trio.py
Fixing /home/amnesia/Persistent/checkout/asgi-lifespan/src/asgi_lifespan/_concurrency/asyncio.py

After:

$ mypy .
Success: no issues found in 15 source files

[codecov-commenter]

Codecov Report

Merging #53 (a660a26) into master (8ef110d) will not change coverage.
The diff coverage is n/a.

❗ Current head a660a26 differs from pull request most recent head c907554. Consider uploading reports for the commit c907554 to get more accurate results

@@            Coverage Diff            @@
##            master       #53   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           13        13           
  Lines          321       321           
=========================================
  Hits           321       321           

Impacted Files	Coverage Δ
src/asgi_lifespan/_concurrency/asyncio.py	100.00% <ø> (ø)
src/asgi_lifespan/_concurrency/trio.py	100.00% <ø> (ø)
src/asgi_lifespan/_manager.py	100.00% <ø> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[AllSeeingEyeTolledEweSew]

I realized no_implicit_optional inserts

from typing import Optional
def f(x: Optional[int] = None) -> None:
   ...

But your local code style uses

import typing
def f(x: typing.Optional[int] = None) -> None:
   ...

I updated the change appropriately

[florimondmanca]

Thanks @AllSeeingEyeTolledEweSew. I've also pushed a commit to explicitly set the mypy version we're testing against.

[florimondmanca]

Some cleanup to do on the repo, as things haven't been updated in a while. Hold on…

[florimondmanca]

Thanks @AllSeeingEyeTolledEweSew! I'll do some more cleanup and updates, then release a new version.