gem-hunter

This plugin allows gulp to populate a virtual filesystem and feed it to the Rollup ES6 module bundler.

Note: This plugin is not appropriate for most use cases, as it requires every file expected to be imported by Rollup to be loaded into memory preemptively. rollup-stream is preferred for almost all purposes. If you want to transform/synthesize/alias/etc. the files Rollup processes, use Rollup plugins; if there's no Rollup plugin to do what you want, try the gulp-to-Rollup plugin adapter, rollup-plugin-gulp. If you really need to synthesize your files in gulp, go ahead and use gulp-rollup—that's what it's made for.

npm install --save-dev gulp-rollup

var gulp       = require('gulp'),
    rollup     = require('gulp-rollup');

gulp.task('bundle', function() {
  gulp.src('./src/**/*.js')
    // transform the files here.
    .pipe(rollup({
      // any option supported by Rollup can be set here.
      input: './src/main.js'
    }))
    .pipe(gulp.dest('./dist'));
});

var gulp       = require('gulp'),
    rollup     = require('gulp-rollup'),
    sourcemaps = require('gulp-sourcemaps');

gulp.task('bundle', function() {
  gulp.src('./src/**/*.js')
    .pipe(sourcemaps.init())
      // transform the files here.
      .pipe(rollup({
        input: './src/main.js'
      }))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest('./dist'));
});

If an array of strings is passed into options.input, a separate bundle will be rolled up from each entry point. They will be processed in parallel and output in no particular order. As usual, each bundle will have the same path as the associated entry file.

In addition, a Promise that resolves to a string or array of strings can be passed into options.input. This is to make it more convenient to use asynchronous methods to locate entry files.

In addition to the standard Rollup options, gulp-rollup supports options.rollup, allowing you to use an older, newer, or custom version of Rollup by passing in the module like so:

gulp.src('./src/**/*.js')
  .pipe(rollup({
    rollup: require('rollup'),
    input: './src/main.js'
  }))
  //...

If options.allowRealFiles is set to true, gulp-rollup will break the gulp plugin guidelines just for you and allow Rollup to read files directly from the filesystem when a file with a matching name isn't found in the gulp stream. You could use this to weasel your way out of having to use rollup-stream, but that would make you a terrible person.

By default, gulp-rollup will mimic Rollup by adding a .js extension to imports if necessary. You can customize this behavior by setting options.impliedExtensions to an array of extensions, like ['.js', '.es', '.jsx']. If options.impliedExtensions is set to false or an empty array, file extensions in imports will be treated as mandatory.

If options.separateCaches is supplied, it should be an object with property names corresponding to entry files. For each of those entry files, options.cache will be overridden with the corresponding property value. This is most useful in conjunction with the 'bundle' event:

var gulp       = require('gulp'),
    rollup     = require('gulp-rollup');

var caches = {};
gulp.task('bundle', function() {
  gulp.src('./src/**/*.js')
    .pipe(rollup({
      input: ['./src/main1.js', './src/main2.js'],
      separateCaches: caches
    }))
    .on('bundle', function(bundle, name) {
      caches[name] = bundle;
    })
    .pipe(gulp.dest('./dist'));
});

If options.generateUnifiedCache is set to true, gulp-rollup will try to construct a cache representing every file imported by any entry point, to be passed into future Rollup invocations (thus obviating the need for options.separateCaches) and deliver it via the 'unifiedcache' event. This should always work as long as all of the plugins you use have deterministic output. Since the internal structure of Rollup's cache objects can't be expected to remain stable, this option isn't guaranteed to work if you specify an options.rollup.

tl;dr: It works like this:

var gulp       = require('gulp'),
    rollup     = require('gulp-rollup');

var cache;
gulp.task('bundle', function() {
  gulp.src('./src/**/*.js')
    .pipe(rollup({
      input: ['./src/main1.js', './src/main2.js'],
      cache: cache,
      generateUnifiedCache: true
    }))
    .on('unifiedcache', function(unifiedCache) {
      cache = unifiedCache;
    })
    .pipe(gulp.dest('./dist'));
});