pylint's return code is still 0 when analysed code contains useless-suppressions

[MarkCBell]

Steps to reproduce

Given a file a.py:

def foo(x):  # pylint: disable=unused-argument
    return x+1

Current behavior

Result of pylint a.py --disable=all --enable=useless-suppression:

a.py:1:0: I0021: Useless suppression of 'unused-argument' (useless-suppression)

however the return code of this is command 0. This makes it much more difficult create CI/CD pipelines that check whether there are unneeded suppressions, for example.

This appears to be because of the fact that even though a message is added to the reporter, the MSG_TYPES_STATUS of info messages is 0. Hence when this message is parsed, msg_status is or'ed with 0 and so the return code of the command is still 0.

Expected behavior

The return code should be non-zero since a check which was enabled has failed.

There are a number of different ways to achieve this including:

1. Change MSG_TYPES_STATUS['I'] to a non-zero number so that raising any info messages results in a non-zero exit code
2. Change the useless-suppression from type info to be type warning

pylint --version output

Result of pylint --version output:

pylint 2.7.4
astroid 2.5.2
Python 3.8.5 (default, Jan 27 2021, 15:41:15) 
[GCC 9.3.0]

[dbaty]

In the meantime, you may be interested in the pylint-strict-informational plugin which, once installed, transforms informational messages as warnings.

[TylerYep]

Though 1) sounds fine, I really hope 2) is eventually implemented (enabling useless-suppression by default), even though it's a breaking change. Enabling useless-suppression by default helps clean up repositories considerably as Pylint improves, and matches the behavior of tools like mypy or flake8+yesqa.

[papb]

@dbaty That plugin did not work for me unfortunately, should it still work with latest pylint?

[papb]

@TylerYep @dbaty I managed to make another workaround, see Polyconseil/pylint-strict-informational#2