gulp-css-usage

A Gulp task which scans your JavaScript classes, including React JSX files support ( .jsx / .js ) as well as HTML files, your CSS files, and gives you a report of CSS coverage.
.i.e how many class names are needless and which are those class names.

In this way, you can tremendously accelerate the rendering time of your app by reducing network latency, loading and parsing time, as the CSS file is smaller with less properties to process and etc.

Install

npm install gulp-css-usage --save-dev

Usage

include the plug-in

// ECMAScript 5 code, using require()
var gulp = require('gulp');
var gulpCssUsage = require('gulp-css-usage').default;

// ECMAScript 6 code, using module import
import gulp from 'gulp';
import gulpCssUsage from 'gulp-css-usage';

using the plug-in

gulp.task('check-css-usage', function () {
  return gulp.src('/.../path/to/your/jsx/files/**/*.{jsx,js}')
    .pipe(gulpCssUsage({css: '/.../path/to/your/css/file/style.css', babylon:[]}));
});

console output

// selectors that matched complete strings in js files
needless selectors:
.myClass
#myId

// selectors that partialy matched an ES6 template string in js files
probably needless selectors:
.myClassTemplate
#myIdTemplate

options

css

mandatory Type: String || Array

The file path/pattern to the CSS file which this plug-in will test.
Supports multiple files either via glob pattern or via array of paths/patterns.

e.g.

gulpCssUsage({css: '/.../path/to/css/*.css'});
gulpCssUsage({css: ['/.../path/to/css/*.css', '/.../another/path/*.css', '/.../just/a/file/style.css']});

threshold

Type: Number, (between 0-100)

If set, gulp-css-usage will check the amount of unused selectors, and if the amount of it is above the threshold then it fails the task.

babylon

Type: Array:String Default: ['jsx', 'flow', 'classProperties']

Array containing the plugins that you want to enable.
Since we're using babel 6.4+ and babylon to parse and extract the class names from the jsx files, you might need to add which plug-ins to enable to parse your code if you're using more ES6 or ES7 features.

Example: if you're using objectRestSpread capability which is not in ECMAScript2015 standards - you'll need to add it

For more available plug-ins, go to babel-babylon

outputFile

Type: String

A Path to a report file. If set, gulp-css-usage will write it's analysis both to console and to the file specified with a .txt extension.

Having some trouble? Have an issue?

For bugs and issues, please use the Issues page.

For trouble in usage or unclear stuff, please use the awesome StackOverflow and tag your question with gulp-css-usage, as well as other tags as you see fit

Road map

• support of more CSS selectors
• support of precompiled SCSS files as well

Contribute

Sure! just fork this repository and join in!