Stylelint

Stylelint is an open-source style sheet linter for CSS and CSS-like syntaxes. It helps teams enforce consistent conventions and catch errors in stylesheets, supporting CSS and, with the appropriate tools, preprocessors such as SCSS or Less.

Stylelint operates on a rule-based system. It ships with a comprehensive set of core rules that cover syntax, property ordering, naming, and formatting, and it can be extended with presets and plugins. Users can enable, disable, or customize rules, and can build their own rule sets or adopt widely used configurations such as stylelint-config-standard.

Configuration is defined in a stylelint.config.js file, a .stylelintrc.json, or via package.json, using extends to reuse presets and a rules object to enforce preferences. The ignoreFiles option lets teams exclude certain directories or files.

Stylelint can be run from the command line, as a Node API, or integrated into editors, build systems, and continuous integration pipelines. The --fix flag enables automatic correction of a subset of issues. It can parse CSS directly or use a custom syntax (for example postcss-scss) or plugins like stylelint-scss for SCSS-specific rules.

The project is maintained by the Stylelint community and contributors. It is released under the MIT license and has a large ecosystem of plugins and shareable configurations, including stylelint-config-standard and stylelint-config-recommended-scss.

Usage typically involves installing the package as a development dependency and running stylelint on source files, with the option to extend configurations and enable automatic fixes where supported.