`python.linting.ignorePatterns` config value is ignored even if `python.analysis.ignore` is not set

[debonte]

Environment data

• Language Server version: 2023.3.23

Code Snippet

test.py

x: int = "str"

settings.json

"python.linting.ignorePatterns": ["test.py"]

Repro Steps

1. Create Python file that generates any diagnostics. Example above.
2. Ignore that file via python.linting.ignorePatterns in settings.json. Ensure python.analysis.ignore is not set.

Expected behavior

No diagnostics reported for Python file.

Actual behavior

Diagnostics. Looks like the problem is that python.analysis.ignore defaults to an empty list, so the following assignment does not cause serverSettings.ignoreFileSpecs to be set to the python.linting.ignorePatterns value as expected:

serverSettings.ignoreFileSpecs = tryGetStringValues(
    pythonAnalysisSection.ignore ?? pythonSection?.linting?.ignorePatterns
);

[erictraut]

Why would pylance pay attention to the setting python.linting.ignorePatterns? Shouldn't this setting be reserved for linters like pylint?

[Spitfire1900]

@erictraut

[Spitfire1900]

I tried the following workaround to no avail: "python.analysis.ignore": null

[erictraut]

My point is that I don't think that Pylance should pay any attention to the python.linting.ignorePatterns setting under any conditions. It's a setting that is not applicable to Pylance. It's designed for use with other tools — specifically, linters like pylint or flake8. Pylance should honor the setting python.analysis.ignore, which accepts an array of globs patterns for files or directories that you would like it to ignore.

[debonte]

@heejaechang, what was the argument for supporting python.linting.ignorePatterns in Pylance?

[heejaechang]

we had a bug about supporting ignorePatterns - #3261

we can discuss whether we should use ignorePatterns or not, but our previous decision was using it (since we accepted the request as enhencement)

and regardless how we decide, it looks like there is a bug how we check both ignored and ignorePatterns settings.

[erictraut]

My recommendation is to consider removing support for python.linter.ignorePatterns in pylance. IMO, this is not a setting that pylance should honor. It is intended for linters, not type analyzers. The python.analysis.ignore is the setting that should be used for pylance.

[heejaechang]

tagging @judej @luabud for decision.

[luabud]

@karthiknadig can correct me if I'm wrong, but I think the plan is to deprecate the python.linting.ignorePatterns namespace once there's no longer built-in support for linters in the Python extension. So it might be better to remove support for it in Pylance, and only use the analysis namespace for Pylance's settings.
I think there was a similar discussion happening around another setting on the Python extension side, but I don't recall what it was. Do you remember, Karthik?

[karthiknadig]

the plan is to deprecate the python.linting.ignorePatterns namespace once there's no longer built-in support for linters in the Python extension.

Yes, once linters are fully moved to their own extensions we plan on removing the support for the ignorePatterns in the Python extension.

[Spitfire1900]

In practice why would the two settings ever be set to different values?

I can’t think of one and that’s sounds like the probable rationale for the current behavior as documented.

[erictraut]

Because linters and type checkers are two different classes of tools that have different purposes. There is some overlap, but they're quite distinct. The settings for one tool should not impact the settings for another tool. If you happen to want to set the same settings for both, you should be able to do this, but you shouldn't be forced to have the same settings for both.