Support for disabling specific rules from auto-fixing on save

[foucdeg]

When coding, it is annoying that our temporary imports and variables that we haven't yet used are removed every time we save the file.

We'd like the Ruff extension to auto-fix on save in general (and we have that activated using editor.codeActionsOnSave), but not F401 (unused imports) and F841 (unused variables).

We do want the rule to autofix in other contexts (pre-commit hook, CI). Is there a way to do that?

[phillies]

I totally agree. Especially once #247 is fixed the automatic fix of F401 and F841 might lead to confusion and annoyance. I guess we would need 2 configuration sets, one for creating the warnings/highlights and one for fixing.

I would propose maybe something like this

    "ruff.args": [
        "--line-length=97",
        "--select=C,E,F,W,B,E501,I001",
        "--extend-ignore=E203"
    ],
    "ruff.fixAll.args": [
        "--line-length=97",
        "--select=C,E,F,W,B,E501,I001",
        "--extend-ignore=E203,F841,F401"
    ],

[francesco086]

I'm also interested as F401 drives me nut. I had to disable it altogether for now.

[albertotb]

This feature would be awesome, I have to keep re-typing imports whenever I comment out parts of the code while developing.

[charliermarsh]

Totally hear you. I should note that you can disable the fix for F401 entirely via:

    "ruff.args": [
        "--unfixable=F401"
    ],

This'll prevent Ruff from removing unused imports on save. But it'll also prevent Ruff from removing unused imports when you run "Fix all" and such, so it's not a perfect solution.

[aneeshusa]

Just discussed this with Charlie live at PyCon - we currently have "ruff.lint.args": ["--ignore=F401"] in VSCode workspace settings to set the default for our org, but not ruff.toml so this is still enforced in CI. We would like to be able to "opt-in" to removing unused imports in VSCode, some ideas we discussed:

• VSCode user settings don't work as workspace settings take precedence
• Having an explicit VSCode action for this - either as part of Organize Imports or a standalone "Remove unused imports" action
• Making F401 only run when saving a file, but not while just editing (not sure if this is too aggressive)

[T-256]

• VSCode user settings don't work as workspace settings take precedence

@aneeshusa Does #457 solve it? you can set new ruff.configurationPreference in your VSCode settings.

[Cito]

Note that in newer versions of ruff you need to set

    "ruff.lint.args": [
        "--unfixable=F401"
    ],

[amaurygelin]

Note that in newer versions of ruff you need to set

    "ruff.lint.args": [
        "--unfixable=F401"
    ],

Hello, it does not work for me, unused imports are still deleted.
Here is my settings.json:

"[python]": {
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "source.fixAll": "explicit",
    "source.organizeImports": "explicit"
  },
  "editor.defaultFormatter": "charliermarsh.ruff"
},
"ruff.nativeServer": true,
"ruff.lint.args": [
  "--unfixable=F401"
],

[dhruvmanila]

@amaurygelin The ruff.lint.args setting isn't used by the native server (you've set ruff.nativeServer to true). For the native server, there are multiple options based on your use-case:

1. You can use a local configuration file (pyproject.toml) which will be picked up by Ruff
2. Use a global configuration file and define it in ruff.configuration

[T-256]

We do want the rule to autofix in other contexts (pre-commit hook, CI). Is there a way to do that?

2. Use a global configuration file and define it in ruff.configuration

Could we make it to accept json values?
It'd be easier for user than creating files manually and pass cross-platform aware paths.

"ruff.nativeServer": true,
"ruff.configuration": {
   "unfixable": ["F401", "F801"]
}

we can either drop string value support for ruff.configuration in favor of {"extend": "path/to/ruff.toml"} value, Or we can separate this setting.

I believe this setting also helps to:

• Support Ruff configuration settings as VS Code extension options #6
• A problem when using format file for ruff in Windows and Linux  #441
• Using config file in devcontainers #450

[dhruvmanila]

Could we make it to accept json values?
It'd be easier for user than creating files manually and pass cross-platform aware paths.

We considered this for the configuration proposal but decided against it for now because:

1. We want to provide auto-completion, which requires including the entire schema in package.json.
2. Compatibility with different Ruff versions is a challenge. Shipping a schema tied to a specific extension version could limit flexibility since we allow users to use a specific Ruff version with ruff.path.

There's an option to allow any value to pass through to Ruff, leaving validation to the executable. However, this might result in a less optimal user experience due to the lack of auto-completion and delayed feedback on settings correctness.

[dhruvmanila]

I'm interested in supporting this and have created an issue with more details at astral-sh/ruff#12709. If anyone wants to work on this, feel free to ping me / comment on the Ruff issue.