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#minify #svg #js #html #css #cli #minify-selectors

minify_selectors_utils

Utilities for minify-selectors

by Adam Gian

5 releases (stable)

2.6.0 Mar 7, 2024
2.4.0 Feb 18, 2023
2.3.3 Feb 4, 2023
2.1.3 Jan 17, 2023
0.2.0 Oct 21, 2022

#2078 in Web programming


Used in 2 crates

Apache-2.0

22KB
487 lines

Latest release version  Apache 2.0 license

minify-selectors

Post-processor that minifies class and ID selector names in CSS, HTML, Javascript and SVG files. minify-selectors aims to offer comprehensive out of the box support with minimal fuss.

Enhance your front-end assets and build optimisations pipeline — wring even more out from your already minified and optimised payload sizes. Additionally can offer a certain degree of obfuscation to your code.


What it can do

HTML and SVGs

Input

<body id="page--default">
  <nav class="site-nav">
    <div class="search has-content">
      <label for="site-search" class="text--muted text--c
        enter">
        Search app
      </label>
      <input type="text" id="site-search" class="form-inp
        ut--single form-input--lg border--thick">
    </div>
  </nav>
</body>

Output:

<body id="a">                                            ‎
  <nav class="b">
    <div class="c a1">
      <label for="y" class="F j">
        Search app
      </label>
      <input type="text" id="y" class="A9 t Av">
    </div>
  </nav>
</body>

Input

<svg xmlns="http://www.w3.org/2000/svg">                 ‎
  <style>
    .icon-background { … }
  </style>
  <g class="icon">
    <circle class="icon-background" fill="url(#dotted)"
      />
  </g>
</svg>

Output:

<svg xmlns="http://www.w3.org/2000/svg">                 ‎
  <style>
    .dz { … }
  </style>
  <g class="d8">
    <circle class="dz" fill="url(#Y)" />
  </g>
</svg>

CSS (and HTML embedded styles)

Input

.sidebar, .site-nav { … }                                ‎
.sidebar .search:focus-within { … }
.sidebar--expanded a.is-active { … }
#page--default { … }

Output:

.a, .b { … }                                             ‎
.a .c:focus-within { … }
.d a.e { … }
#a { … }

JS (and HTML embedded scripts)

Input

for (let link of document.querySelectorAll('a.anchor')) {‎
  link.classList.remove('is-active');
}

Output:

for (let link of document.querySelectorAll('a.Bd')) {    ‎
  link.classList.remove('e');
}

Opt-in or opt-out of selector encoding

In cases where minify-selectors is unable to parse selectors, for example: in custom HTML attributes or JS variables. Or forcing a selector to be encoded when it otherwise would not be, such as in a HTML code element or comments. You can prefix your selector names so that minify-selectors knows to parse it and how to encode it:

  • .__-- or #__-- instead of the selector type ('#' or '.') before selector names
  • __class-- or __id-- for "name only" selectors, use '__class--' for class selectors and '__id--' for ID selectors

Input

<main class="page page-dark">                            ‎
  <button
    class="btn btn-warning"
    data-toggle="modal"
    data-target="#__--prompt-delete-user">
  </button>
</main>
<script>
  view.className = isDarkMode
    ? '__class--page __class--page--dark'
    : '__class--page __class--page--light';
</script>

Output:

<main class="b2 b3">                                     ‎
  <button
    class="a4 a7"
    data-toggle="modal"
    data-target="#bc">
  </button>
</main>
<script>
  view.className = isDarkMode
    ? 'b2 b3'
    : 'b2 b4;
</script>

Or, you do not want minify-selectors to encode certain selectors (for reasons such as SEO). You can prefix your selector names so minify-selectors will leave the name as is (the prefix will be omitted):

  • .__ignore-- and #__ignore-- instead of the selector type ('#' or '.') before selector names
  • __ignore-- for selectors that are "name only"

Input

<nav class="site-nav">                                   ‎
  <a href="/faq/#__ignore--new-user"><a>
<nav>

Output:

<nav class="b">                                          ‎
  <a href="/faq/#new-user"><a>
</div>

How to use

Please note:

  • minify-selectors only supports regular CSS, HTML, JS and SVG files. SASS/SCSS, LESS, TypeScript, JQuery, Handlebars, etc. should be compiled or transpiled first into its respective vanilla form.
  • minify-selectors is currently limited to UTF-8 encoded files.

Via npm and npm scripts

  1. Install minify-selectors via npm:

    npm i minify-selectors

  2. Include minify-selectors in your package.json 'scripts' property, for example:

    "scripts": {
  "build": "npm run build:webpack && npm run build:minify-selectors",
  "build:minify-selectors": "minify-selectors --input \"example/dir/src/\" --output \"example/dir/dist/\"",
  "build:webpack": "webpack --config config/webpack-prod.config.js"
},

  3. Run npm script command, for example:

    npm run build

Running as a CLI tool

  1. Install via homebrew:

    brew tap adamgian/minify-selectors && brew install minify-selectors

  2. Run in command line:

    minify-selectors --input "example/dir/src" --output "example/dir/dist"

Configuration

Command line options

Option Description
--input, -i Directory to process. Any CSS, HTML, JS and SVG files in the given directory and sub-directories will be parsed.
--output, -o Directory to place processed files into. Setting the output path to be the same as the input path will overwrite existing files.
--config, -c Alternatively instead of using CLI arguments, an external JSON config file can be provided instead. See section below: 'External JSON config options' for more information.
--alphabet Optional
String sequence of characters to use when encoding.

Default: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
--start-index Optional
Index to start incrementing and encoding from.

Default: 0
--parallel Optional
Enable concurrent processing.

Default: false
--sort Optional
Reorder selectors by descending frequency before assigning indexes and minifying.

Default: true
--custom-id-attribute Optional
Custom HTML and SVG attributes that contain an ID (or space-separated list of IDs). For example, in Bootstrap you may have data-bs-target="#exampleModal" and data-bs-parent="#accordionExample"

Usage: --custom-id-attribute data-bs-target data-bs-parent
--custom-class-attribute Optional
Custom HTML and SVG attributes that contain a space-separated list of classes.
--custom-selector-attribute Optional
Custom HTML and SVG attributes that contain a selector string.
--custom-anchor-attribute Optional
Custom HTML and SVG attributes that contain a URL.
--custom-style-attribute Optional
Custom HTML and SVG attributes that contain CSS styles.
--custom-script-attribute Optional
Custom HTML and SVG attributes that contain JS code.

External JSON config options

An example config file:

{
    "input": "/User/Adam/Github/project/dist",
    "output": "/User/Adam/Github/project/dist",
    "parallel": true,
    "customAttributes": {
        "id": [
            "data-bs-target",
            "data-bs-parent"
        ]
    }
}
Option Description
input Directory to process. Any CSS, HTML, JS and SVG files in the given directory and sub-directories will be parsed.
output Directory to place processed files into. Setting the output path to be the same as the input path will overwrite existing files.
alphabet Optional
String sequence of characters to use when encoding.

Default: "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
start-index Optional
Index to start incrementing and encoding from.

Default: 0
parallel Optional
Enable concurrent processing.

Default: false
sort Optional
Reorder selectors by descending frequency before assigning indexes and minifying.

Default: true
customAttributes.id Optional
Custom HTML and SVG attributes that contain an ID (or space-separated list of IDs).

Usage: "id": [ "foo", ..., "baz" ]
customAttributes.class Optional
Custom HTML and SVG attributes that contain a space-separated list of classes.

Usage: "class": [ "foo", ..., "baz" ]
customAttributes.selector Optional
Custom HTML and SVG attributes that contain a selector string.

Usage: "selector": [ "foo", ..., "baz" ]
customAttributes.anchor Optional
Custom HTML and SVG attributes that contain a URL.

Usage: "anchor": [ "foo", ..., "baz" ]
customAttributes.style Optional
Custom HTML and SVG attributes that contain CSS styles.

Usage: "style": [ "foo", ..., "baz" ]
customAttributes.script Optional
Custom HTML and SVG attributes that contain JS code.

Usage: "script": [ "foo", ..., "baz" ]

Dependencies

~6.5MB
~163K SLoC