python / python/mypy

"Missing return statement" error for functions having infinite loop unconditionally by looping on non-exhaustive generator

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#7,374 12 comments 13 reactions 0 assignees View on GitHub

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false-positive feature priority-2-low
Dominant language
Python
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Description

When having functions having infinite loop unconditionally by looping on non-exhaustive generator, there should be no return statements after the infinite looping block since all statements after the looping block are unreachable. Therefore, this "Missing return statement" error is a false-positive. The test case exposing this false-positive is implemented in https://github.com/python/mypy/pull/7373 .

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Research direction

Start with the test case in pull request #7373 and trace the missing-return analysis it exercises for a non-exhaustive generator loop. Confirm the existing test reproduces the false positive, then verify that the test passes without reporting a missing return for code after the unconditional loop.

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Assessment

Tech stack
python
Domain
devtools
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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