python
Add a way to ignore `type: ignore`, disabled error codes
Feature
My goal is to check all the ignored inline mypy errors/warnings
Pitch
People often added inline comment # type: ignore to ignore mypy error for a specific line, but it's difficult to trace for other developers, or for audit purpose. Now I would like to have something similar to flake8 --disable-noqa, which show all the mypy errors/warnings regardless of these inline ignores.
There is --warn-unused-ignores, which warns if a type ignore is unused, but there's no option to ignore them completely.
type: ignore does not just change the error reporting, it also changes types of things. Most of the time type: ignore means that the thing behind it becomes Any.
And all parts of code matter for mypy (unlike flake8).
So, I don't think we need such a flag: un-silencing errors in this case can bring very confusing results.
@sobolevn, what do you mean that "it also changes types of things"? My understanding is that mypy simply suppresses any errors on a line with a # type: ignore, and that the comment has no other effect in terms of type checking.
FWIW, pyright has an option that does what @copdips is requesting here (`"enableTypeIgnoreComments": false) to accommodate this use case.
@erictraut, Thx for your trick with vscode, but in fact, I need the option during CICD time. For e.g. with flake8, I run two commands:
flake8
flake8 --disable-noqa --exit-zero
The first one is for the real CI check, and the second one is just for the review/audit. That's why I asked if we have similar thing in mypy.
@erictraut is correct, a #type: ignore comment should only suppress errors on the line, so the proposed feature is a reasonable one.
If you know which code is type checked by mypy, it's easy enough to use some grep-like tool to find type ignores, for example something like this:
$ rg '# *type: *ignore\b'
This doesn't show the errors that are ignored, however.
As a quick hack, you could use sed to temporarily replace, say, # type: ignore with # xtype: ignore, and run mypy normally.
I am in a conundrum because the Unused "type: ignore" comment error seems impossible to ignore in a specific location.
I do have a file that might be missing:
try:
from ._version import version as __version__ # type: ignore
except ImportError: # pragma: no cover
__version__ = "0.1.dev1"
Once mypy is configured to detect unused ignores (useful feature), I cannot make it really ignore this line. Keep in mind that there are two cases here, one where the file exists and one where the file does not exist.
I want to ensure mypy does not annoy me about this particular line only.
@ssbarnea your issue is unrelated to the feature request here, I think it's more related to https://github.com/python/mypy/pull/15164 which should fix your kind of thing (will be included in next release). In particular, see this test case . For now, you can likely hack around it using __import__ or cast or if not TYPE_CHECKING (see some of the examples in #8823)
