Bundling framework files only

build.js

var gulp = require('gulp');
var runSequence = require('run-sequence');
var changed = require('gulp-changed');
var plumber = require('gulp-plumber');
var to5 = require('gulp-babel');
var sourcemaps = require('gulp-sourcemaps');
var paths = require('../paths');
var compilerOptions = require('../babel-options');
var assign = Object.assign || require('object.assign');

// transpiles changed es6 files to SystemJS format
// the plumber() call prevents 'pipe breaking' caused
// by errors from other gulp plugins
// https://www.npmjs.com/package/gulp-plumber
gulp.task('build-system', function () {
  return gulp.src(paths.source)
    .pipe(plumber())
    .pipe(changed(paths.output, {extension: '.js'}))
    .pipe(sourcemaps.init({loadMaps: true}))
    .pipe(to5(assign({}, compilerOptions, {modules:'system'})))
    .pipe(sourcemaps.write({includeContent: false, sourceRoot: paths.sourceMapRelativePath }))
    .pipe(gulp.dest(paths.output));
});

// copies changed html files to the output directory
gulp.task('build-html', function () {
  return gulp.src(paths.html)
    .pipe(changed(paths.output, {extension: '.html'}))
    .pipe(gulp.dest(paths.output));
});

// this task calls the clean task (located
// in ./clean.js), then runs the build-system
// and build-html tasks in parallel
// https://www.npmjs.com/package/gulp-run-sequence
gulp.task('build', function(callback) {
  return runSequence(
    'clean',
    ['build-system', 'build-html', 'bundle'],
    callback
  );
});

bundle.js

var gulp = require('gulp');
var jspm = require('jspm/api');
var paths = require('../paths');
var fs = require('fs');

var bundleIt = function () {
  return jspm.bundle(
    [
      // '*',
      'aurelia-bootstrapper',
      'aurelia-http-client',
      'aurelia-dependency-injection',
      'aurelia-router',
      'github:aurelia/[email protected]',
      'github:aurelia/[email protected]',
      'github:aurelia/[email protected]',
      'github:aurelia/[email protected]',
      'github:aurelia/[email protected]'
    ].join(' + '),
    'app-bundle.js',
    {inject:true, minify: true}
  )
};

gulp.task('bundle', function (done) {
  bundleIt().then(function () {
    fs.rename('app-bundle.js', 'dist/app-bundle.js', done);
  });
});

gulp.task('copy-bundle', function (done) {
  if (fs.existsSync('app-bundle.js')) {
    fs.rename('app-bundle.js', 'dist/app-bundle.js', done);
  } else {
    bundleIt()
  }
});

watch.js

var gulp = require('gulp');
var paths = require('../paths');
var browserSync = require('browser-sync');

// outputs changes to files to the console
function reportChange(event){
  console.log('File ' + event.path + ' was ' + event.type + ', running tasks...');
}

// this task wil watch for changes
// to js, html, and css files and call the
// reportChange method. Also, by depending on the
// serve task, it will instantiate a browserSync session
gulp.task('watch', ['serve'], function() {
  gulp.watch(paths.source, ['build-system', 'copy-bundle', browserSync.reload]).on('change', reportChange);
  gulp.watch(paths.html, ['build-html', browserSync.reload]).on('change', reportChange);
  gulp.watch(paths.style, browserSync.reload).on('change', reportChange);
});