Style Sheets Formatter

CSSfmt is a tool that automatically formats CSS source code, inspired by Gofmt, and built on top of the PostCSS ecosystem.

CSSfmt can format following code:

• Vanilla CSS
• Future CSS syntax using cssnext
• SCSS syntax of Sass
• Nested selectors syntax like SCSS, Less, Stylus and processor using postcss-nested.

CSSfmt'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!

Example

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;
}

Nested selectors

Input (input.css):

      @media screen and (    min-width :699px)
 {.foo    +       .bar,.hoge{
    font-size   :12px      !   important   ;  ~       .fuga     {
      padding      : 10px       5px;
   color:green;
 >p

 {
        line-height             : 1.5          ;
      }}}
     }                /* comment for .class, #id */


.class,           #id
 {     color       : blue;

  border        :solid  #ddd                1px}

Yield:

@media screen and (min-width: 699px) {
  .foo + .bar,
  .hoge {
    font-size: 12px !important;

    ~ .fuga {
      padding: 10px 5px;
      color: green;

      > p {
        line-height: 1.5;
      }
    }
  }
}

/* comment for .class, #id */
.class,
#id {
  color: blue;
  border: 1px solid #ddd;
}

Installation

$ npm install cssfmt 

Usage

in Command Line

CLI Help:

$ cssfmt --help

Usage: cssfmt [options] input-file [output-file]

Options:

  -d, --diff        output diff against original file
  -R, --recursive   format files recursively
  -V, --versions    output the version number
  -h, --help        output usage information

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

$ cat input.css | cssfmt

in Node.js

var fs = require('fs');
var postcss = require('postcss');
var fmt = require('cssfmt');

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

var output = postcss()
  .use(fmt())
  .process(css)
  .css;

in Task Runners

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

Rules

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
• open 1 brank line between rules
• open 1 brank line between rules in atrules
• open 1 brank lines before comments
• require new line between a comment and rules
• disallow any brank lines between @import

for nested selector syntax

• open 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

Option projects

Editor plugins

• atom-cssfmt by @1000ch
• cssfmt.el by @KeenS
• vim-cssfmt by @kewah
• sublime-cssfmt by @dmnsgn

for Task Runners

• grunt-cssfmt
• gulp-cssfmt
• fly-cssfmt
• laravel-elixir-cssfmt by @appleboy

License

The MIT License (MIT)

Copyright (c) 2015 Masaaki Morishita