The streaming build system

[![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][travis-image]][travis-url] [![AppVeyor Build Status][appveyor-image]][appveyor-url] [![Coveralls Status][coveralls-image]][coveralls-url] [![OpenCollective Backers][backer-badge]][backer-url] [![OpenCollective Sponsors][sponsor-badge]][sponsor-url] [![Gitter chat][gitter-image]][gitter-url] ## What is gulp? - **Automation** - gulp is a toolkit that helps you automate painful or time-consuming tasks in your development workflow. - **Platform-agnostic** - Integrations are built into all major IDEs and people are using gulp with PHP, .NET, Node.js, Java, and other platforms. - **Strong Ecosystem** - Use npm modules to do anything you want + over 2000 curated plugins for streaming file transformations - **Simple** - By providing only a minimal API surface, gulp is easy to learn and simple to use ## Installation There are a few ways to install: * gulp v4.0.0 - `npm install gulp@next` * gulp v4.0.0-alpha.3 - `npm install gulpjs/gulp#v4.0.0-alpha.3` * gulp v3.9.1 - `npm install gulp` ## Documentation For a Getting started guide, API docs, recipes, making a plugin, etc. check out our docs! - Check out the [documentation for v4.0.0](/docs/README.md)! __Excuse our dust; these docs might be behind while we get everything updated. Please open an issue if something isn't working.__ - Using the older v3.9.1? Check out the [documentation at the v3.9.1 tag](https://github.com/gulpjs/gulp/tree/v3.9.1/docs)! ## Sample `gulpfile.js` This file will give you a taste of what gulp does. ```js var gulp = require('gulp'); var less = require('gulp-less'); var babel = require('gulp-babel'); var concat = require('gulp-concat'); var uglify = require('gulp-uglify'); var rename = require('gulp-rename'); var cleanCSS = require('gulp-clean-css'); var del = require('del'); var paths = { styles: { src: 'src/styles/**/*.less', dest: 'assets/styles/' }, scripts: { src: 'src/scripts/**/*.js', dest: 'assets/scripts/' } }; /* Not all tasks need to use streams, a gulpfile is just another node program * and you can use all packages available on npm, but it must return either a * Promise, a Stream or take a callback and call it */ function clean() { // You can use multiple globbing patterns as you would with `gulp.src`, // for example if you are using del 2.0 or above, return its promise return del([ 'assets' ]); } /* * Define our tasks using plain functions */ function styles() { return gulp.src(paths.styles.src) .pipe(less()) .pipe(cleanCSS()) // pass in options to the stream .pipe(rename({ basename: 'main', suffix: '.min' })) .pipe(gulp.dest(paths.styles.dest)); } function scripts() { return gulp.src(paths.scripts.src, { sourcemaps: true }) .pipe(babel()) .pipe(uglify()) .pipe(concat('main.min.js')) .pipe(gulp.dest(paths.scripts.dest)); } function watch() { gulp.watch(paths.scripts.src, scripts); gulp.watch(paths.styles.src, styles); } /* * You can use CommonJS `exports` module notation to declare tasks */ exports.clean = clean; exports.styles = styles; exports.scripts = scripts; exports.watch = watch; /* * Specify if tasks run in series or parallel using `gulp.series` and `gulp.parallel` */ var build = gulp.series(clean, gulp.parallel(styles, scripts)); /* * You can still use `gulp.task` to expose tasks */ gulp.task('build', build); /* * Define default task that can be called by just running `gulp` from cli */ gulp.task('default', build); ``` ## Use latest JavaScript version in your gulpfile Node already supports a lot of **ES2015**, to avoid compatibility problem we suggest to install Babel and rename your `gulpfile.js` as `gulpfile.babel.js`. ```sh npm install --save-dev babel-register babel-preset-es2015 ``` Then create a **.babelrc** file with the preset configuration. ```js { "presets": [ "es2015" ] } ``` And here's the same sample from above written in **ES2015**. ```js import gulp from 'gulp'; import less from 'gulp-less'; import babel from 'gulp-babel'; import concat from 'gulp-concat'; import uglify from 'gulp-uglify'; import rename from 'gulp-rename'; import cleanCSS from 'gulp-clean-css'; import del from 'del'; const paths = { styles: { src: 'src/styles/**/*.less', dest: 'assets/styles/' }, scripts: { src: 'src/scripts/**/*.js', dest: 'assets/scripts/' } }; /* * For small tasks you can export arrow functions */ export const clean = () => del([ 'assets' ]); /* * You can also declare named functions and export them as tasks */ export function styles() { return gulp.src(paths.styles.src) .pipe(less()) .pipe(cleanCSS()) // pass in options to the stream .pipe(rename({ basename: 'main', suffix: '.min' })) .pipe(gulp.dest(paths.styles.dest)); } export function scripts() { return gulp.src(paths.scripts.src, { sourcemaps: true }) .pipe(babel()) .pipe(uglify()) .pipe(concat('main.min.js')) .pipe(gulp.dest(paths.scripts.dest)); } /* * You could even use `export as` to rename exported tasks */ function watchFiles() { gulp.watch(paths.scripts.src, scripts); gulp.watch(paths.styles.src, styles); } export { watchFiles as watch }; /* * You can still use `gulp.task` * for example to set task names that would otherwise be invalid */ const clean = gulp.series(clean, gulp.parallel(styles, scripts)); gulp.task('clean', clean); /* * Export a default task */ export default build; ``` ## Incremental Builds You can filter out unchanged files between runs of a task using the `gulp.src` function's `since` option and `gulp.lastRun`: ```js const paths = { ... images: { src: 'src/images/**/*.{jpg,jpeg,png}', dest: 'build/img/' } } function images() { return gulp.src(paths.images.src, {since: gulp.lastRun(images)}) .pipe(imagemin({optimizationLevel: 5})) .pipe(gulp.dest(paths.images.dest)); } function watch() { gulp.watch(paths.images.src, images); } ``` Task run times are saved in memory and are lost when gulp exits. It will only save time during the `watch` task when running the `images` task for a second time. If you want to compare modification time between files instead, we recommend these plugins: - [gulp-changed]; - or [gulp-newer] - supports many:1 source:dest. [gulp-newer] example: ```js function images() { var dest = 'build/img'; return gulp.src(paths.images) .pipe(newer(dest)) // pass through newer images only .pipe(imagemin({optimizationLevel: 5})) .pipe(gulp.dest(dest)); } ``` If you can't simply filter out unchanged files, but need them in a later phase of the stream, we recommend these plugins: - [gulp-cached] - in-memory file cache, not for operation on sets of files - [gulp-remember] - pairs nicely with gulp-cached [gulp-remember] example: ```js function scripts() { return gulp.src(scriptsGlob) .pipe(cache('scripts')) // only pass through changed files .pipe(header('(function () {')) // do special things to the changed files... .pipe(footer('})();')) // for example, // add a simple module wrap to each file .pipe(remember('scripts')) // add back all files to the stream .pipe(concat('app.js')) // do things that require all files .pipe(gulp.dest('public/')) } ``` ## Want to contribute? Anyone can help make this project better - check out our [Contributing guide](/CONTRIBUTING.md)! ## Backers Support us with a monthly donation and help us continue our activities. [![Backers][backers-image]][support-url] ## Sponsors Become a sponsor to get your logo on our README on Github. [![Sponsors][sponsors-image]][support-url] [downloads-image]: https://img.shields.io/npm/dm/gulp.svg [npm-url]: https://www.npmjs.com/package/gulp [npm-image]: https://img.shields.io/npm/v/gulp.svg [travis-url]: https://travis-ci.org/gulpjs/gulp [travis-image]: https://img.shields.io/travis/gulpjs/gulp.svg?label=travis-ci [appveyor-url]: https://ci.appveyor.com/project/gulpjs/gulp [appveyor-image]: https://img.shields.io/appveyor/ci/gulpjs/gulp.svg?label=appveyor [coveralls-url]: https://coveralls.io/r/gulpjs/gulp [coveralls-image]: https://img.shields.io/coveralls/gulpjs/gulp/master.svg [gitter-url]: https://gitter.im/gulpjs/gulp [gitter-image]: https://badges.gitter.im/gulpjs/gulp.svg [backer-url]: #backers [backer-badge]: https://opencollective.com/gulpjs/backers/badge.svg?color=blue [sponsor-url]: #sponsors [sponsor-badge]: https://opencollective.com/gulpjs/sponsors/badge.svg?color=blue [support-url]: https://opencollective.com/gulpjs#support [backers-image]: https://opencollective.com/gulpjs/backers.svg [sponsors-image]: https://opencollective.com/gulpjs/sponsors.svg [gulp-cached]: https://github.com/contra/gulp-cached [gulp-remember]: https://github.com/ahaurw01/gulp-remember [gulp-changed]: https://github.com/sindresorhus/gulp-changed [gulp-newer]: https://github.com/tschaub/gulp-newer