vscode-rubocop

This is the official VS Code extension for RuboCop.

You can install this VS Code extension from the Visual Studio Marketplace.

For VS Code-based IDEs like VSCodium or Eclipse Theia, the extension can be installed from the Open VSX Registry.

Language Server Capabilities

These are the capabilities of this extension, each enabled by RuboCop's built-in LSP server.

It supports the following capabilities:

• Fast Diagnostics (Linting)
• Fast Document Formatting
• Execute Command (Trigger autocorrect)

:star2: Pro tip: Enabling Format On Save is recommended. By activating just this one setting, code gets autocorrected every time a file is saved. Don't miss out on this game-changing boost to your development experience!

Requirements

• RuboCop 1.53.0+
• VS Code 1.75.0+

Configuration

The extension only offers a few of its own configuration options, but because it conforms to the VS Code Formatting API, several general editor settings can impact the extension's behavior as well.

Configuring the VS Code editor to use RuboCop

There are two general editor settings that you'll want to verify are set in order to use RuboCop as your formatter.

editor.formatOnSave

To automatically format your Ruby with RuboCop, check Format on Save in the Formatting settings under Text Editor:

Or, in settings.json:

"editor.formatOnSave": true,

editor.defaultFormatter

Next, if you have installed multiple extensions that provide formatting for Ruby files (it's okay if you're not sure—it can be hard to tell), you can specify RuboCop as your formatter of choice by setting editor.defaultFormatter under a "[ruby]" section of settings.json like this:

"[ruby]": {
  "editor.defaultFormatter": "rubocop.vscode-rubocop"
},

Configuring RuboCop extension options

To edit RuboCop's own options, first expand Extensions and select RuboCop from the sidebar of the Settings editor.

rubocop.mode

The Mode setting determines how (and whether) RuboCop runs in a given workspace. Generally, it will try to execute rubocop via bundle exec if possible, and fall back on searching for a global rubocop bin in your PATH.

• "Always run—whether via Bundler or globally" (JSON: enableUnconditionally) this mode will first attempt to run via Bundler, but if that fails for any reason, it will attempt to run rubocop in your PATH
• [Default] "Run unless the bundle excludes rubocop" (JSON: enableViaGemfileOrMissingGemfile) this mode will attempt to run RuboCop via Bundler, but if a bundle exists and the rubocop gem isn't in it (i.e. you're working in a project doesn't use RuboCop), the extension will disable itself. If, however, no bundle is present in the workspace, it will fall back on the first rubocop executable in your PATH
• "Run only via Bundler, never globally" (JSON: enableViaGemfile) the same as the default enableViaGemfileOrMissingGemfile, but will never run rubocop from your PATH (as a result, single-file windows and workspace folders without a Gemfile may never activate the extension)
• "Run only globally, never via Bundler" (JSON: onlyRunGlobally) if you want to avoid running the bundled version of RuboCop, this mode will never interact with Bundler and will only run rubocop on your PATH
• "Disable the extension" (JSON: disable) disable the extension entirely

Or, in settings.json:

"rubocop.mode": "enableViaGemfile",

rubocop.autocorrect

The autocorrect option does what it says on the tin. if you don't want RuboCop to automatically edit your documents on save, you can disable it here:

You might want to disable this if you're using RuboCop to highlight problems but don't want it to edit your files automatically. You could also accomplish this by disabling editor.formatOnSave, but as that's a global setting across all languages, it's more straightforward to uncheck this extension setting.

Or, in settings.json:

"rubocop.autocorrect": true,

rubocop.safeAutocorrect

This feature requires RuboCop 1.54+ to be enabled.

When autocorrect is enabled, safeAutocorrect controls its safety. By default, it is enabled to perform safe autocorrections. If you disable it, unsafe autocorrections will also be performed, you can disable it here:

Or, in settings.json:

"rubocop.safeAutocorrect": false,

rubocop.lintMode

This feature requires RuboCop 1.55+ to be enabled.

Run lint only cops (rubocop -l). If you only want to enable the feature as a linter like ruby -w, you can conveniently set it here:

Or, in settings.json:

"rubocop.lintMode": true,

rubocop.layoutMode

This feature requires RuboCop 1.55+ to be enabled.

Run layout only cops. If you only want to enable the feature as a formatter, you can conveniently set it here:

Or, in settings.json:

"rubocop.layoutMode": true,

Furthermore, enabling autocorrect with the editor.formatOnSave to the effect of rubocop -x command line option.

rubocop.commandPath

As described above, the extension contains logic to determine which version of rubocop to launch. If you want a specific binary to run instead, you can set it here.

This will override whatever search strategy is set in rubocop.mode (except for disable, in which case the extension will remain disabled).

Or, in settings.json:

{
  "rubocop.commandPath": "${userHome}/.rbenv/shims/rubocop"
}

rubocop.yjitEnabled

This extension supports YJIT, which can speed up the built-in language server in RuboCop. The rubocop.yjitEnabled option is enabled by default.

You can disable YJIT by unchecking.

Or, in settings.json:

"rubocop.yjitEnabled": false

Changing settings only for a specific project

You may want to apply certain settings to a specific project, which you can do by configuring them in the Workspace scope as opposed to the global User scope.

Clicking "Workspace" before changing a setting will save it to .vscode/settings.json inside the root workspace directory and will not affect the extension's behavior in other workspace folders.

Manually triggering a format with autocorrects

In addition to the built-in VS Code Formatting API, you can trigger the extension to format and autocorrect the current file listing by running the command "RuboCop: Format with Autocorrects". This is equivalent to rubocop -a:

This is handy if you don't want to enable format-on-save, already have another formatter associated with Ruby files, want to format your code before saving, or just want to bind a shortcut to RuboCop's formatting action.

To map a keybind to the command, search for it by name in the Keyboard Shortcuts editor:

Or, in keybindings.json:

[
  {
    "key": "ctrl+alt+cmd+f",
    "command": "rubocop.formatAutocorrects"
  }
]

You can also trigger the extension to format and autocorrect all the current file listing by running the command "RuboCop: Format All with Autocorrects". This is equivalent to rubocop -A:

This command "RuboCop: Format All with Autocorrects" requires RuboCop 1.56+ to be enabled.

You can use two autocorrect commands depending on the purpose.

Decoding the Status Bar item

The extension also includes a status bar item to convey the status of the current file listing at a glance.

When the file conforms to RuboCop without issue:

When the file contains a low-severity formatting issue:

When the file contains a normal linter error:

When the file fails to parse at all:

Clicking the status bar item will open the problems tab:

Limitations

There's some room for improvement yet, but it isn't yet clear whether these limitations will be a big deal in practice:

• The extension will only launch a single instance of rubocop --lsp per workspace. If you're using a multi-root workspace, they'll all be handled by whatever RuboCop version is found in the first one
• RuboCop's LSP only supports "Full" text document synchronization, both because it seemed hard to implement incremental sync correctly and because attempting to pass RuboCop's runner a partial document would result in inconsistent formatting results

Acknowledgements

This extension's codebase was initially based on Standard Ruby's vscode-standard-ruby and Kevin Newton's vscode-syntax-tree extension, which has a similar architecture (VS Code language client communicating with a long-running Ruby process via STDIO). Thank you!

Code of Conduct

This project follows The RuboCop Community Code of Conduct.