Unexpected unused type ignore alt #16680
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This test currently fails with this error:
AssertionError: Command 3 (dmypy check -- bar.py) did not give expected output
--- Captured stderr call ---
Expected:
bar.py:2: error: Unused "type: ignore" comment (diff)
== Return code: 1 (diff)
Actual:
(empty)
It demonstrates a bug that when an module is removed using
`FineGrainedBuildManager.update` because it is not "seen" by
`fine_grained_increment_follow_imports`, then "unused type: ignore"
warnings disappear from subsequent checks.
Ref: python#9655
This test fails with the error:
AssertionError: Command 3 (dmypy check -- bar.py) did not give expected output
--- Captured stderr call ---
Expected:
bar.py:2: error: "type: ignore" comment without error code [ignore-without-code] (diff)
== Return code: 1 (diff)
Actual:
(empty)
This test illustrates that '"type: ignore" comment without error code'
errors currently disappear in the same way that 'Unused "type: ignore"'
errors do as described in python#9655.
Ref: python#9655
This test fails with the error:
AssertionError: Command 3 (dmypy check -- bar.py) did not give expected output
--- Captured stderr call ---
Expected:
bar.py:4: error: Name "a" may be undefined [possibly-undefined] (diff)
== Return code: 1 (diff)
Actual:
(empty)
This test illustrates that possibly-undefined errors currently disappear
in the same way that 'Unused "type: ignore"' errors do as described in python#9655.
Ref: python#9655
These tests show how some errors disappear on a re-run of dmypy after a file is altered.
This which fixes issue python#9655 wherein some types of error would be lost when a file was re-processed by dmypy. Regression tests are also included. This also fixes another error where sometimes files would not be re-processed by dmypy if the only error in the file was either "unused type ignore" or "ignore without code".
This catches a regression caused by the previous commits where "type: ignore" comments are erroneously marked as unused in re-runs of dmypy. As far as I can tell, this only happens in modules which contain an import that we don't know how to type (such as a module which does not exist), and a submodule which is unused.
Before this change, fine-grained builds could spuriously mark ignored legitimate errors as "unused ignores". By keeping track of these ignored errors we ensure that enough analysis is done to know that the ignored lines are actually useful. We have to change is_errors_for_file so that we don't consider files as faulty when all of their errors were hidden.
seddonym
commented
Dec 19, 2023
| @@ -3078,7 +3078,7 @@ def load_graph( | |||
| path=bs.path, | |||
| source=bs.text, | |||
| manager=manager, | |||
| root_source=not bs.followed, | |||
| root_source=not (bs.followed or bs.module == "builtins"), | |||
There was a problem hiding this comment.
Prior to this, root_source was True for builtins, which seemed incorrect? But I'm not sure of the intent.
The reason for adding this here is because of this check when constructing the State:
https://github.com/seddonym/mypy/blob/7e61402902f14fae93c0327d146172657f43c4c4/mypy/build.py#L1941
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Prior to this commit, messages would sometimes not be present in only_once_messages, causing an error. This uses the discard method which won't error if the message isn't present.
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for more information, see https://pre-commit.ci
|
According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
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(Explain how this PR changes mypy.)