Modern CSS Formatter

stylefmt is a tool that automatically formats CSS according to stylelint rules.

stylefmt'd code is:

easier to write : never worry about minor formatting concerns while hacking away.
easier to read : when all code looks the same you need not mentally convert others' formatting style into something you can understand.
easier to maintain : mechanical changes to the source don't cause unrelated changes to the file's formatting; diffs show only the real changes.
uncontroversial : never have a debate about spacing or brace position ever again!

NOTICE: Consider other tools before adopting stylefmt

If you are using stylefmt with stylelint configuration to format according to its rules, you can now use stylelint's --fix option (from v7.11.0) to autofix.

Another on the other hand, prettier supports to format not only JavaScript but also CSS, SCSS and Less code.

Features

Supports the latest CSS syntax: Including custom properties, range context for media features, calc() and nesting.
Understands CSS-like syntaxes: stylefmt is powered by PostCSS, so it understands any syntax that PostCSS can parse, including SCSS.
Works well with stylelint: stylelint is a mighty, modern CSS linter. stylefmt can understand the formatting rules specified in your stylelint configuration file (.stylelintrc).

Examples

Future CSS syntax (cssnext)

Input (input.css):

/* custom properties */
:root{--fontSize: 1rem;
  --mainColor       :#12345678;
--highlightColor:hwb(190, 35%, 20%);
}

/* custom media queries */
@custom-media

--viewport-medium(width<=50rem);

/* some var() & calc() */
body{color:var(--mainColor);
    font-size:var(--fontSize);
 line-height: calc(var(--fontSize) * 1.5);
padding: calc((var(--fontSize) / 2) + 1px)}

/* custom media query usage */
@media (--viewport-medium) {
body {font-size: calc(var(--fontSize) * 1.2); }
}

/* custom selectors */
@custom-selector :--heading h1,h2,h3,    h4,h5,h6;
:--heading { margin-top:0 }

/* colors stuff */
a{
color:var(--highlightColor);
    transition:color 1s;
}
a:hover{color  :gray(255,50%) }
a:active{color : rebeccapurple }
a:any-link { color:color(var(--highlightColor) blackness(+20%)) }

/* font stuff */
h2 {font-variant-caps:small-caps;
}table{font-variant-numeric: lining-nums;
}

/* filters */
.blur{filter:blur(4px)}.sepia{
filter: sepia(.8);}

Yield:

/* custom properties */
:root {
  --fontSize: 1rem;
  --mainColor: #12345678;
  --highlightColor: hwb(190, 35%, 20%);
}

/* custom media queries */
@custom-media --viewport-medium (width <= 50rem);

/* some var() & calc() */
body {
  color: var(--mainColor);
  font-size: var(--fontSize);
  line-height: calc(var(--fontSize) * 1.5);
  padding: calc((var(--fontSize) / 2) + 1px);
}

/* custom media query usage */
@media (--viewport-medium) {
  body {
    font-size: calc(var(--fontSize) * 1.2);
  }
}

/* custom selectors */
@custom-selector :--heading h1, h2, h3, h4, h5, h6;

:--heading {
  margin-top: 0;
}

/* colors stuff */
a {
  color: var(--highlightColor);
  transition: color 1s;
}

a:hover {
  color: gray(255, 50%);
}

a:active {
  color: rebeccapurple;
}

a:any-link {
  color: color(var(--highlightColor) blackness(+20%));
}

/* font stuff */
h2 {
  font-variant-caps: small-caps;
}

table {
  font-variant-numeric: lining-nums;
}

/* filters */
.blur {
  filter: blur(4px);
}

.sepia {
  filter: sepia(.8);
}

SCSS syntax

Input (input.scss):

// mixin for clearfix


        @mixin      clearfix    ()      { &:before,
  &:after {
                content:" ";
    display              : table;  }

  &:after        {clear: both;}
   }.class
{
       padding:10px;@include        clearfix();}
     .base {  color: red;  }

// placeholder
%base
{


padding: 12px
}

.foo{
@extend      .base;}

.bar
      {     @extend            %base;

}

Yield:

// mixin for clearfix
@mixin clearfix () {
  &:before,
  &:after {
    content: " ";
    display: table;
  }

  &:after {
    clear: both;
  }
}

.class {
  padding: 10px;
  @include clearfix();
}

.base {
  color: red;
}

// placeholder
%base {
  padding: 12px;
}

.foo {
  @extend .base;
}

.bar {
  @extend %base;
}

Installation

$ npm install stylefmt

Usage

in Command Line

CLI Help:

$ stylefmt --help

Usage: stylefmt [options] input-name [output-name]

Options:

  -b, --config-basedir   Path to the directory that relative paths defining "extends"
  -c, --config           Path to a specific configuration file (JSON, YAML, or CommonJS)
  -d, --diff             Output diff against original file
  -r, --recursive        Format list of space seperated files(globs) in place
  -v, --version          Output the version number
  -h, --help             Output usage information
  -i, --ignore-path      Path to a file containing patterns that describe files to ignore.
  --stdin-filename       A filename to assign stdin input.

stylefmt can also read a file from stdin if there are no input-file as argument in CLI.

$ cat input.css | stylefmt --stdin-filename input.css

in Node.js

var fs = require('fs');
var postcss = require('postcss');
var scss = require('postcss-scss'); // when you use scss syntax
var stylefmt = require('stylefmt');

var css = fs.readFileSync('input.css', 'utf-8');

postcss([
  stylefmt
]).process(css, {
    from: 'input.css',
    syntax: scss
  })
  .then(function (result) {
    result.css; // formatted code
  });

in Task Runners

We can use stylefmt in Grunt, gulp, and Fly.

stylelint rules that stylefmt can handle

stylefmt :heart: stylelint

stylefmt supports the following stylelint rules:

and we can also format from the other stylelint's configration files or packages (e.g. stylelint-config-standard, stylelint-config-suitcss and so on) using extends property.

Default formatting rules (without stylelint config file)

Basic

2 spaces indentation
require 1 space between a simple selector and combinator
require 1 space between selectors and {
require new line after {
disallow any spaces between property and :
require 1 space between : and values
require new line after declarations
require ; in last declaration
require 1 space between values and !important
disallow any spaces between ! and important
leave 1 blank line between rules
leave 1 blank line between rules in atrules
disallow any blank lines between @import

for nested selector syntax

leave 1 line between declarations and nested rules

SCSS

require 1 space between @mixin and mixin name
require 1 space between mixin name and (
require 1 space between @extend and base rules
require 1 space between @include and mixin name
disallow any spaces between $variable and :
require 1 space between : and name of variable

stylefmt

stylefmt is a tool that automatically formats stylesheets.