understrap/gulpfile.js

// Defining requirements
var gulp = require( 'gulp' );
var plumber = require( 'gulp-plumber' );
var sass = require( 'gulp-sass' );
var watch = require( 'gulp-watch' );
var cssnano = require( 'gulp-cssnano' );
var rename = require( 'gulp-rename' );
var concat = require( 'gulp-concat' );
var uglify = require( 'gulp-uglify' );
var merge2 = require( 'merge2' );
var imagemin = require( 'gulp-imagemin' );
var ignore = require( 'gulp-ignore' );
var rimraf = require( 'gulp-rimraf' );
var clone = require( 'gulp-clone' );
var merge = require( 'gulp-merge' );
var sourcemaps = require( 'gulp-sourcemaps' );
var browserSync = require( 'browser-sync' ).create();
var del = require( 'del' );
var cleanCSS = require( 'gulp-clean-css' );
var gulpSequence = require( 'gulp-sequence' );
var replace = require( 'gulp-replace' );
var autoprefixer = require( 'gulp-autoprefixer' );

// Configuration file to keep your code DRY
var cfg = require( './gulpconfig.json' );
var paths = cfg.paths;

// Run:
// gulp sass + cssnano + rename
// Prepare the min.css for production (with 2 pipes to be sure that "theme.css" == "theme.min.css")
gulp.task( 'scss-for-prod', function() {
    var source =  gulp.src( paths.sass + '/*.scss' )
        .pipe( plumber({
            errorHandler: function( err ) {
                console.log( err );
                this.emit( 'end' );
            }
        }) )
        .pipe( sourcemaps.init({ loadMaps: true }) )
        .pipe( sass() );

    var pipe1 = source.pipe( clone() )
        .pipe( sourcemaps.write(undefined, { sourceRoot: null }) )
        .pipe( gulp.dest( paths.css ) )
        .pipe( rename( 'custom-editor-style.css' ) );


    var pipe2 = source.pipe( clone() )
        .pipe( minify-css() )
        .pipe( rename( {suffix: '.min'} ) )
        .pipe( gulp.dest( paths.css ) );

    return merge(pipe1, pipe2);
});


// Run:
// gulp sourcemaps + sass + reload(browserSync)
// Prepare the child-theme.css for the development environment
gulp.task( 'scss-for-dev', function() {
    gulp.src( paths.sass + '/*.scss' )
        .pipe(plumber({
            errorHandler: function( err ) {
                console.log( err );
                this.emit( 'end' );
            }
        }))
        .pipe( sourcemaps.init({ loadMaps: true }) )
        .pipe( sass() )
        .pipe( sourcemaps.write(undefined, { sourceRoot: null }) )
        .pipe( gulp.dest(paths.css) );
});

gulp.task( 'watch-scss', ['browser-sync'], function() {
    gulp.watch( paths.sass + '/**/*.scss', ['scss-for-dev'] );
});


// Run:
// gulp sass
// Compiles SCSS files in CSS
gulp.task( 'sass', function() {
    var stream = gulp.src( paths.sass + '/*.scss' )
        .pipe( plumber({
            errorHandler: function( err ) {
                console.log( err );
                this.emit( 'end' );
            }
        }) )
        .pipe( sass() )
        .pipe( autoprefixer( 'last 2 versions' ) )
        .pipe( gulp.dest(paths.css) )
        .pipe( rename( 'custom-editor-style.css' ) );
    return stream;
});


// Run:
// gulp watch
// Starts watcher. Watcher runs gulp sass task on changes
gulp.task( 'watch', function() {
    gulp.watch( paths.sass + '/**/*.scss', ['styles'] );
    gulp.watch( [paths.dev + '/js/**/*.js','js/**/*.js','!js/theme.js','!js/theme.min.js'], ['scripts'] );

    //Inside the watch task.
    gulp.watch( paths.imgsrc + '/**', ['imagemin-watch'] );
});

/**
 * Ensures the 'imagemin' task is complete before reloading browsers
 * @verbose
 */
gulp.task( 'imagemin-watch', ['imagemin'], function(done) {
  browserSync.reload();
  done();
});

// Run:
// gulp imagemin
// Running image optimizing task
gulp.task( 'imagemin', function(){
    gulp.src( paths.imgsrc + '/**' )
    .pipe( imagemin() )
    .pipe( gulp.dest(paths.img) );
});


// Run:
// gulp cssnano
// Minifies CSS files
gulp.task( 'cssnano', function(){
  return gulp.src( paths.css + '/theme.css' )
    .pipe( sourcemaps.init({ loadMaps: true }) )
    .pipe( plumber({
            errorHandler: function( err ) {
                console.log( err );
                this.emit( 'end' );
            }
        }) )
    .pipe( rename({ suffix: '.min' }) )
    .pipe( cssnano({ discardComments: { removeAll: true } }) )
    .pipe( sourcemaps.write('./') )
    .pipe( gulp.dest( paths.css ) );
});

gulp.task( 'minify-css', function() {
  return gulp.src( paths.css + '/theme.css' )
  .pipe( sourcemaps.init({loadMaps: true}) )
    .pipe( cleanCSS({ compatibility: '*' }) )
    .pipe( plumber({
            errorHandler: function( err ) {
                console.log( err );
                this.emit( 'end' );
            }
        }) )
    .pipe( rename({ suffix: '.min' }) )
     .pipe( sourcemaps.write('./' ))
    .pipe( gulp.dest( paths.css ));
});

gulp.task( 'cleancss', function() {
  return gulp.src( paths.css + '/*.min.css', { read: false } ) // much faster
    .pipe(ignore( 'theme.css' ))
    .pipe( rimraf() );
});

gulp.task( 'styles', function(callback){
    gulpSequence( 'sass', 'minify-css' )(callback);
});
 

// Run:
// gulp browser-sync
// Starts browser-sync task for starting the server.
gulp.task( 'browser-sync', function() {
    browserSync.init(cfg.browserSyncWatchFiles, cfg.browserSyncOptions);
});


// Run:
// gulp watch-bs
// Starts watcher with browser-sync. Browser-sync reloads page automatically on your browser
gulp.task( 'watch-bs', ['browser-sync', 'watch', 'scripts'], function() { });


// Run: 
// gulp scripts. 
// Uglifies and concat all JS files into one
gulp.task( 'scripts', function() {
    var scripts = [

        // Start - All BS4 stuff
        paths.dev + '/js/bootstrap4/bootstrap.js',

        // End - All BS4 stuff

        paths.dev + '/js/skip-link-focus-fix.js'
    ];
  gulp.src(scripts)
    .pipe( concat( 'theme.min.js' ) )
    .pipe( uglify() )
    .pipe( gulp.dest(paths.js) );

  gulp.src(scripts)
    .pipe( concat( 'theme.js' ) )
    .pipe( gulp.dest(paths.js) );
});

// Deleting any file inside the /src folder
gulp.task( 'clean-source', function() {
  return del(['src/**/*']);
});

// Run:
// gulp copy-assets.
// Copy all needed dependency assets files from bower_component assets to themes /js, /scss and /fonts folder. Run this task after bower install or bower update

////////////////// All Bootstrap SASS  Assets /////////////////////////
gulp.task( 'copy-assets', function() {

////////////////// All Bootstrap 4 Assets /////////////////////////
// Copy all JS files

  
    var stream = gulp.src(paths.node + 'bootstrap/dist/js/**/*.js')
        .pipe(gulp.dest(paths.dev + '/js/bootstrap4'));
// Copy all Bootstrap SCSS files
    gulp.src(paths.node + 'bootstrap/scss/**/*.scss')
        .pipe(gulp.dest(paths.dev + '/sass/bootstrap4'));
    return stream;

////////////////// End Bootstrap 4 Assets /////////////////////////

// Copy all Font Awesome Fonts
    var stream = gulp.src(paths.node + 'font-awesome/fonts/**/*.{ttf,woff,woff2,eof,svg}')
        .pipe( gulp.dest( './fonts' ) );

// Copy all Font Awesome SCSS files
    gulp.src(paths.node + 'font-awesome/scss/*.scss')
        .pipe( gulp.dest(paths.dev + '/sass/fontawesome') );

// _s SCSS files
    gulp.src(paths.node + 'undescores-for-npm/sass/media/*.scss')
        .pipe( gulp.dest(paths.dev + '/sass/underscores') );

// _s JS files into /src/js
    gulp.src(paths.node + 'undescores-for-npm/js/skip-link-focus-fix.js')
        .pipe( gulp.dest(paths.dev + '/js') );

// _s JS files into /js
    gulp.src(paths.node + 'undescores-for-npm/js/skip-link-focus-fix.js')
        .pipe( gulp.dest(paths.js + paths.vendor) );

// Copy Popper JS files
        
    gulp.src(paths.node + 'popper.js/dist/umd/popper.min.js')
        .pipe( gulp.dest(paths.js + paths.vendor) );
    gulp.src(paths.node + 'popper.js/dist/umd/popper.js')
        .pipe( gulp.dest(paths.js + paths.vendor) );
    return stream;
});

// Deleting the files distributed by the copy-assets task
gulp.task( 'clean-vendor-assets', function() {
  return del([paths.dev+'/js/bootstrap4/**', paths.dev+'/sass/bootstrap4/**', './fonts/*wesome*.{ttf,woff,woff2,eof,svg}', paths.dev+'/sass/fontawesome/**', paths.dev+'/sass/underscores/**', paths.dev+'/js/skip-link-focus-fix.js', paths.js+'/**/skip-link-focus-fix.js', paths.js+'/**/popper.min.js', paths.js+'/**/popper.js', (paths.vendor!=''?(paths.js+paths.vendor+'/**'):'')]);
});

// Run
// gulp dist
// Copies the files to the /dist folder for distribution as simple theme
gulp.task( 'dist', ['clean-dist'], function() {
  return gulp.src(['**/*', '!'+paths.bower, '!'+paths.bower+'/**', '!'+paths.node, '!'+paths.node+'/**', '!'+paths.dev, '!'+paths.dev+'/**', '!'+paths.dist, '!'+paths.dist+'/**', '!'+paths.distprod, '!'+paths.distprod+'/**', '!'+paths.sass, '!'+paths.sass+'/**', '!readme.txt', '!readme.md', '!package.json', '!package-lock.json', '!gulpfile.js', '!gulpconfig.json', '!CHANGELOG.md', '!.travis.yml', '!jshintignore',  '!codesniffer.ruleset.xml',  '*'], {'buffer': false})
  .pipe( replace('/js/jquery.slim.min.js', '/js'+paths.vendor+'/jquery.slim.min.js', { 'skipBinary': true }) )
  .pipe( replace('/js/popper.min.js', '/js'+paths.vendor+'/popper.min.js', {'skipBinary': true}) )
  .pipe( replace('/js/skip-link-focus-fix.js', '/js'+paths.vendor+'/skip-link-focus-fix.js', {'skipBinary': true}) )
    .pipe( gulp.dest(paths.dist) );
});

// Deleting any file inside the /dist folder
gulp.task( 'clean-dist', function() {
  return del([paths.dist + '/**']);
});

// Run
// gulp dist-product
// Copies the files to the /dist-prod folder for distribution as theme with all assets
gulp.task( 'dist-product', ['clean-dist-product'], function() {
  return gulp.src(['**/*', '!'+paths.bower, '!'+paths.bower+'/**', '!'+paths.node, '!'+paths.node+'/**', '!'+paths.dist, '!'+paths.dist+'/**', '!'+paths.distprod, '!'+paths.distprod+'/**', '*'])
    .pipe( gulp.dest(paths.distprod) );
});

// Deleting any file inside the /dist-product folder
gulp.task( 'clean-dist-product', function() {
  return del([paths.distprod + '/**']);
});