Settings

Published Nov 5, 2026 · Updated Nov 6, 2026 by Claude

All settings live under rubyTemplates. and can be set per user or per workspace. For example, in .vscode/settings.json:

{
  "rubyTemplates.erb.disabledDiagnostics": ["Html/ImgAlt"],
  "rubyTemplates.slim.extraEngines": ["mjml"],
  "rubyTemplates.preview.useRails": true
}

A .ruby-templates.toml in the project sets the diagnostics, formatting and Slim engine settings below too, and wins over them where it says something; see the rules reference.

Editor settings for one template language use its language id, such as [erb], [haml], [slim] or [erb-js]; File types lists the ids.

Diagnostics

Setting	Default	Description
`rubyTemplates.erb.disabledDiagnostics`	`[]`	Built-in ERB diagnostics to turn off, by rule name.
`rubyTemplates.haml.disabledDiagnostics`	`[]`	Built-in Haml diagnostics to turn off, by rule name.
`rubyTemplates.jbuilder.disabledDiagnostics`	`[]`	Built-in diagnostics to turn off in Jbuilder and Builder views, by rule name.
`rubyTemplates.slim.disabledDiagnostics`	`[]`	Built-in Slim diagnostics to turn off, by rule name.
`rubyTemplates.erb.diagnostics.enabled`	`true`	Show the language server’s diagnostics in ERB files. Turn off to silence them all.
`rubyTemplates.haml.diagnostics.enabled`	`true`	Show the language server’s diagnostics in Haml files. Turn off to silence them all.
`rubyTemplates.slim.diagnostics.enabled`	`true`	Show the language server’s diagnostics in Slim and Skim files. Turn off to silence them all.

Each disabledDiagnostics setting takes the rule names of that language’s checks (Html/ImgAlt; the kebab-case codes of earlier versions still work); the diagnostics reference lists them. Errors as you type shows examples.

Formatting

Setting	Default	Description
`rubyTemplates.erb.format.enabled`	`true`	Let the language server format ERB files (Format Document and Format Selection with the built-in formatter). Turn off for no edits.
`rubyTemplates.erb.format.alignComments`	`false`	Move the lines inside an ERB template’s HTML comments (`<!-- … -->`) and multi-line `<%# … %>` comments with the line the comment opens on, keeping their relative indentation. Off: those lines keep their bytes.
`rubyTemplates.haml.format.enabled`	`true`	Let the language server format Haml files (Format Document and Format Selection). Turn off for no edits.
`rubyTemplates.slim.format.enabled`	`true`	Let the language server format Slim and Skim files (Format Document and Format Selection). Turn off for no edits.

The indentation width isn’t a setting of its own: it comes from the editor’s tab size, then .editorconfig, then 2. See Formatting.

Editing

Setting	Default	Description
`rubyTemplates.erb.autoCloseTags`	`true`	Typing the `>` of an HTML start tag in ERB inserts its end tag after the cursor (like html.autoClosingTags for plain HTML).

Rails

Setting	Default	Description
`rubyTemplates.routes.enabled`	`true`	Read the app’s routes with `bin/rails runner` (boots the app once, and again when config/routes.rb or config/routes/.rb changes) for completion, hover and go to definition of `_path` / `*_url` helpers in views.

Routes are read in trusted workspaces only.

Slim

Setting	Default	Description
`rubyTemplates.slim.extraEngines`	`[]`	Embedded engine names registered by your app (e.g. `mjml`) that the unknown-engine check should accept.

.skim files use the slim settings.

Preview and compiled source

Setting	Default	Description
`rubyTemplates.slim.compileForRails`	`false`	Show Compiled Ruby Source for Slim runs `slimrb --rails`: ActionView output buffer and no capture, as Rails compiles it.
`rubyTemplates.preview.refreshOnSave`	`true`	Re-render the HTML preview whenever the template is saved.
`rubyTemplates.preview.useBundler`	`false`	Prefix render commands with `bundle exec` when a Gemfile exists in the workspace.
`rubyTemplates.preview.useRails`	`false`	Render the preview through the app’s `bin/rails runner` (`ApplicationController.render(inline:, type:)`) when the file is inside a Rails app, so helpers, routes and partials work. Boots the app on every refresh and gives up after 60 seconds.

Ruby tools

Setting	Default	Description
`rubyTemplates.commands.slimrb`	`"slimrb"`	Executable used to render Slim (gem install slim).
`rubyTemplates.commands.haml`	`"haml"`	Executable used to render Haml (gem install haml).
`rubyTemplates.commands.html2haml`	`"html2haml"`	Executable for ERB → Haml (gem install html2haml).
`rubyTemplates.commands.haml2slim`	`"haml2slim"`	Executable for Haml → Slim (gem install haml2slim).
`rubyTemplates.commands.erb2slim`	`"erb2slim"`	Executable for ERB → Slim (gem install html2slim).
`rubyTemplates.commands.ruby`	`"ruby"`	Ruby used to preview and compile ERB through Erubi (gem install erubi; stdlib ERB without it) and for Haml → ERB through the haml_to_erb library (gem install haml_to_erb).

These are the executables that preview, Show Compiled Ruby Source and the converters call; see Commands.

Language server

Setting	Default	Description
`rubyTemplates.server.enabled`	`true`	Run the Rust language server (diagnostics, go to partial, completions, hover, and the built-in ERB, Haml and Slim formatting).
`rubyTemplates.server.path`	`""`	Path to the ruby-templates-ls binary. Leave empty to use the bundled one.