PostCSS Hash

PostCSS plugin to replace output file names with HASH algorithms (md5, sha256, sha512, etc) and string length of your choice - for cache busting.

# input 
postcss input.css -o output.css
 
# output 
output.a1b2c3d4e5.css
 
# ./manifest.json 
{
  "output.css": "output.a1b2c3d4e5.css",
}
 

# input 
postcss css/in/*.css --dir css/out/
 
# output 
file1.a516675ef8.css
file2.aa36634cc4.css
file3.653f682ad9.css
file4.248a1e8f9e.css
file5.07534806bd.css
 
# ./manifest.json 
{
  "file1.css": "file1.a516675ef8.css",
  "file2.css": "file2.aa36634cc4.css",
  "file3.css": "file3.653f682ad9.css",
  "file4.css": "file4.248a1e8f9e.css",
  "file5.css": "file5.07534806bd.css"
}

Usage

// postcss.config.js
module.exports = (ctx) => ({
    plugins: {
        'postcss-hash': {
            algorithm: 'sha256',
            trim: 20,
            manifest: './manifest.json'
        },
    }
});

Options

algorithm (string, default: 'md5')

Uses node's inbuilt crypto module. Pass any digest algorithm that is supported in your environment. Possible values are: md5, md4, md2, sha, sha1, sha224, sha256, sha384, sha512.

includeMap (boolean, default: false)

Setting includeMap to true will allow postcss-hash to hash the name of the sourcemap, as well hash the CSS including the sourceMappingURL comment. You can set this option to true if you care about the hashed fingerprints matching the contents of the CSS file, and don't mind a performance hit of regenerating the CSS twice.

trim (number, default: 10)

Hash's length.

manifest (string, default: './manifest.json')

Will output a manifest file with key: value pairs.

name `(function, default: ({dir, name, hash, ext}) => path.join(dir, name + '.' + hash + ext)

Pass a function to customise the name of the output file. The function is given an object of string values:

• dir: the directory name as a string
• name: the name of the file, excluding any extensions
• hash: the resulting hash digest of the file
• ext: the extension of the file

NOTE:

1. The values will be either appended or replaced. If this file needs be recreated on each run, you'll have to manually delete it.
2. keys are generated with files' basename. If you have ./input/A/one.css & ./input/B/one.css, only the last entry will exist.

See PostCSS docs for examples for your environment.

Version: 0.2.0
Updated on: August 29, 2017