Whether `lint.per-file-ignores` is respected depends on the file pattern when working in multi-root workspaces

[shunichironomura]

Description

When working in Multi-root Workspaces in Visual Studio Code, whether lint.per-file-ignores takes effect depends on the file pattern.

The extension settings are all set to defaults, except for the ruff.configuration.

Reproduction

Set-up

Follow the steps below or clone https://github.com/shunichironomura/ruff-vscode-ws

1. Prepare a directory with the following structure and contents:

(EDIT: Fixed the structure by adding the subfolder/)

.
├── a.code-workspace
├── b
│   └── a.py
├── ruff.toml
├── subfolder/
└── t
    └── a.py

a.code-workspace:

{
    "folders": [
        {
            "name": "root",
            "path": "."
        },
        {
            "name": "subfolder",
            "path": "./subfolder"
        }
    ],
    "settings": {
        "ruff.configuration": "${workspaceFolder:root}/ruff.toml"
    }
}

b/a.py and t/a.py (both have the same contents):

import os

ruff.toml:

[lint.per-file-ignores]
"b/**.py" = ["F401"]
"t/**.py" = ["F401"]  # This can be `"t/*.py" = ...` and still get the same issue

2. Open the directory as a multi-root workspace by code a.code-workspace

Expected behavior

• Running ruff check . in the root results in reporting no error.
• For both scripts (b/a.py and t/a.py), no error is shown in the editor.

Actual behavior

• Running ruff check . in the root results in reporting no error. (As expected)
• The error message of F401 is not shown in b/a.py, but is shown in t/a.py. (Unexpected)

Environment

• Ruff version: 0.5.4
• Ruff VS Code extension version: v2024.36.0
• Operating system: WSL2 Linux (Ubuntu 22.04)
• Python version: 3.12.4

[dhruvmanila]

Thanks for preparing a way for us to reproduce this very easily! It really helps.

This seems like a bug. I can look at it later today.

[dhruvmanila]

Ok, if I remove the ruff.configuration settings from a.code-workspace, then it works correctly.

    "settings": {
        "ruff.configuration": "${workspaceFolder:root}/ruff.toml"
    }

[dhruvmanila]

I'm curious as to why do you want to specify the ruff.configuration setting as it's going to be taken by default even if you don't specify it.

[shunichironomura]

In my actual codebase, specifying the ruff.configuration setting makes the extension show some rule (I001 to be specific) correctly in the editor (maybe it's another, related bug). I tried to make a minimal reproducible example but I couldn't.