Fixed invalid regex handling in filterwarnings

[virendrapatil24]

closes #13119

• Updated the parse_warning_filter method to handle invalid regex pattern provided to message/module args.
• Added a test case in testing/test_warnings.py to validate the new behavior.
• Created a changelog fragment to document this improvement.

[The-Compiler]

Nice! Definitely much better. New output (with my small suggestion added):

ERROR: while parsing the following warning configuration:

  ignore::DeprecationWarning:*

This error occurred:

Invalid regex '*': nothing to repeat at position 0

[nicoddemus]

LGTM, thanks!

[graingert]

I think it would be more thorough to test on the whole "while parsing ..." output?

[graingert]

it looks like there's no tests for "invalid lineno (negative AND not an integer)", too many fields, invalid action or resolving the warning category

perhaps you'd be interested in adding these tests? Should be very similar to test_invalid_regex_in_filterwarning perhaps in this PR or perhaps in a followup?

[virendrapatil24]

Thanks for the review!

I’m a bit confused about what else is required for this PR. Could you summarize the key changes you’d like to see here? From my understanding, the missing tests you mentioned might be better suited for a follow-up rather than this ticket. Let me know your thoughts!

[graingert]

Thanks for the review!

I’m a bit confused about what else is required for this PR. Could you summarize the key changes you’d like to see here? From my understanding, the missing tests you mentioned might be better suited for a follow-up rather than this ticket. Let me know your thoughts!

So yeah could you:

• Assert on the exit code of pytester
• Assert on the full output starting with "while parsing the following warning configuration: ..." in the stderr.fnmatch_lines assertion

[virendrapatil24]

Thanks for the review!
I’m a bit confused about what else is required for this PR. Could you summarize the key changes you’d like to see here? From my understanding, the missing tests you mentioned might be better suited for a follow-up rather than this ticket. Let me know your thoughts!

So yeah could you:

• Assert on the exit code of pytester
• Assert on the full output starting with "while parsing the following warning configuration: ..." in the stderr.fnmatch_lines assertion

sure will make those asserts, thanks for clarifying.

[graingert]

I think you need to escape this star or it will treat it as a wildcard/fnmatch syntax. I'm not sure how to escape it though

Suggested change

	"Invalid regex '*': nothing to repeat at position 0",
	r"Invalid regex '\*': nothing to repeat at position 0",

[virendrapatil24]

makes sense, I will check what I can do here.

[virendrapatil24]

we can escape * using [*]
ref: https://docs.python.org/3/library/fnmatch.html