stylelint

What is stylelint?

Stylelint is a powerful, modern linter that helps you avoid errors and enforce consistent conventions in your stylesheets. It is configurable and supports the latest CSS syntax as well as CSS-like syntaxes, such as SCSS.

What are stylelint's main functionalities?

Linting CSS files

This command will lint all CSS files in the 'src' directory and its subdirectories. It will check for errors and code quality issues based on the rules defined in the configuration.

"stylelint 'src/**/*.css'"

Fixing CSS files

This command will not only lint the CSS files but also attempt to fix any fixable issues, such as formatting inconsistencies, automatically.

"stylelint 'src/**/*.css' --fix"

Custom configuration

This JSON represents a custom Stylelint configuration object where specific rules are defined, such as disallowing invalid hex colors, setting indentation preferences, and enforcing no leading zero for numbers.

{ "rules": { "color-no-invalid-hex": true, "indentation": [2, { "except": ["block"] }], "number-leading-zero": "never" } }

Extending configurations

This JSON represents a Stylelint configuration that extends a shared configuration, in this case, 'stylelint-config-standard', which is a popular set of rules that enforce common stylistic conventions.

{ "extends": "stylelint-config-standard" }

Using plugins

This JSON represents a Stylelint configuration that includes a plugin, 'stylelint-scss', which adds SCSS-specific linting rules to Stylelint. The configuration then enables a rule from that plugin to disallow unknown at-rules in SCSS.

{ "plugins": ["stylelint-scss"], "rules": { "scss/at-rule-no-unknown": true } }

Other packages similar to stylelint

eslint

ESLint is a static code analysis tool for identifying problematic patterns in JavaScript code. It is similar to Stylelint in its extensibility and plugin ecosystem but is focused on JavaScript rather than stylesheets.

prettier

Prettier is an opinionated code formatter that supports many languages, including CSS. Unlike Stylelint, which can both lint and fix code, Prettier is solely focused on code formatting and does not provide linting functionalities.

sass-lint

Sass-lint is a node-only Sass linter for both sass and scss syntax. It is similar to Stylelint when working with SCSS files but does not support plain CSS or other CSS-like syntaxes.

csslint

CSSLint is a tool that helps to point out problems with your CSS code. It is less configurable than Stylelint and has a smaller set of rules and plugins, but it serves a similar purpose in linting CSS files.

README

Stylelint

A mighty, modern linter that helps you avoid errors and enforce conventions in your styles.

Features

It's mighty as it:

• has over 170 built-in rules for modern CSS syntax and features
• supports plugins so you can create your own rules
• automatically fixes problems where possible
• is well tested with over 15000 unit tests
• supports shareable configs that you can extend or create
• is unopinionated so that you can customize it to your exact needs
• complements pretty printers like Prettier
• has a growing community and is used by Google, GitHub and WordPress

And can be extended to:

• parse CSS-like syntaxes like SCSS, Sass, Less and SugarSS
• extract embedded styles from HTML, Markdown and CSS-in-JS object & template literals

How it'll help you

It'll help you avoid errors, for example:

• invalid things, e.g. malformed hex colors and named grid areas
• unknown things, e.g. units and functions that aren't in the CSS specs
• valid things that are problematic, e.g. duplicated selectors and overridden properties

And enforce non-stylistic conventions, for example:

• what units, functions, at-rules etc are allowed
• consistent patterns for selector names, at-rule names, custom properties etc
• maximum specificity or maximum quantity of each selector type
• your preferred notation for color functions, font weight etc

There are also rules for enforcing stylistic conventions, but we now recommend you use Stylelint alongside a pretty printer like Prettier. Linters and pretty printers are complementary tools that work together.

Example output

Guides

• User guide
  • Getting started
  • Configuration
  • Rules
  • Usage
    • CLI
    • Node.js API
    • PostCSS plugin
    • Options
  • Integrations
    • Editor integrations
    • Task runner integrations
    • Other integrations
  • Ignoring code
  • Combining rules
  • Using regex
  • Errors & warnings
• Developer guide
  • Working on rules
  • Writing plugins
  • Writing custom syntaxes
  • Writing custom formatters
  • Writing system tests
  • Writing processors
• Migration guide
  • Migrating to 14.0.0
• Maintainer guide
  • Managing issues
  • Managing pull requests
  • Performing releases
• About
  • Vision
  • Semantic versioning

Contributors

Stylelint is maintained by volunteers. Without the code contributions from all these fantastic people, Stylelint would not exist. Become a contributor.

Sponsors

Thank you to all our sponsors! Become a sponsor.

Backers

Thank you to all our backers! Become a backer.

Website hosting

License

The MIT License.

Changelog

14.16.1

• Fixed: customSyntax resolution with configBasedir (#6536) (@ybiquitous).
• Fixed: declaration-block-no-duplicate-properties autofix for !important (#6528) (@sidx1024).
• Fixed: function-no-unknown false positives for scroll, -webkit-gradient, color-stop, from, and to (#6539) (@Mouvedia).
• Fixed: value-keyword-case false positives for mixed case ignoreFunctions option (#6517) (@kimulaco).
• Fixed: unexpected output in Node.js API lint result when any rule contains disableFix: true (#6543) (@adrianjost).