gulpfile.js

var gulp = require('gulp'),
    jshint = require('gulp-jshint'),
    gulpif = require('gulp-if'),
    concat = require('gulp-concat'),
    uglify = require('gulp-uglify'),
    cleanCSS = require('gulp-clean-css'),
    removeCode = require('gulp-remove-code'),
    merge = require('merge-stream'),
    del = require('del'),
    zip = require('gulp-zip'),
    gzip = require('gulp-gzip'),
    htmlmin = require('gulp-htmlmin'),
    replace = require('gulp-replace'),
    fs = require('fs'),
    smoosher = require('gulp-smoosher');

var demoMode = false;
var testMode = false;

function clean() {
    return del(['dist']);
}

function clean2() {
    return del(['dist/js', 'dist/css']);
}
function lint() {
    return gulp.src('www/js/**/app.js')
        .pipe(jshint())
        .pipe(jshint.reporter('default'));
}

function Copytest() {
    return merge(
        gulp.src(['www/index.html'])
        .pipe(removeCode({production: false}))
        .pipe(removeCode({cleanheader: true}))
         .pipe(gulp.dest('dist')),
        gulp.src(['www/images/**/*.*'])
            .pipe(gulp.dest('dist/images'))
    )
}

function Copy() {
    return merge(
        gulp.src(['www/index.html'])
        .pipe(removeCode({production: true}))
        .pipe(removeCode({cleanheader: true}))
         .pipe(gulp.dest('dist')),
        gulp.src(['www/images/**/*.*'])
            .pipe(gulp.dest('dist/images'))
    )
}

function concatApptest() {
    return merge(
        gulp.src([ 'www/js/**/*.js'])
            .pipe(concat('app.js'))
            .pipe(removeCode({production: false}))
            .pipe(removeCode({cleanheader: true}))
            .pipe(gulp.dest('./dist/js')),

        gulp.src([ 'www/css/**/*.css'])
            .pipe(concat('style.css'))
            .pipe(gulp.dest('./dist/css/'))
    )
}

function concatApp() {
    return merge(
        gulp.src([ 'www/js/**/*.js'])
            .pipe(concat('app.js'))
            .pipe(removeCode({production: true}))
            .pipe(removeCode({cleanheader: true}))
            .pipe(gulp.dest('./dist/js')),

        gulp.src([ 'www/css/**/*.css'])
            .pipe(concat('style.css'))
            .pipe(gulp.dest('./dist/css/'))
    )
}

function replaceSVG() {
    return gulp.src('dist/index.html')
        .pipe(replace(/<!-- replaceSVG -->(.*?)<!-- \/replaceSVG -->/g, function (match, p1) {
            return fs.readFileSync('dist/images/jogdial.svg', 'utf8');
        }))
        .pipe(gulp.dest('dist'))
}

function minifyApp() {
    return merge(
        gulp.src(['dist/js/app.js'])
            .pipe(uglify({mangle: true}))
            .pipe(gulp.dest('./dist/js/')),

        gulp.src('dist/css/style.css')
            .pipe(cleanCSS({debug: true}, function(details) {
                console.log(details.name + ': ' + details.stats.originalSize);
                console.log(details.name + ': ' + details.stats.minifiedSize);
            }))
            .pipe(gulp.dest('./dist/css/')),

        gulp.src('dist/index.html')
            .pipe(htmlmin({collapseWhitespace: true, minifyCSS: true}))
            .pipe(gulp.dest('dist'))
    )
}

function includehtml() {
    return merge(
        gulp.src('dist/index.html')
            .pipe(replace(/<file-include w3-include-html="'sub\/(.*?)'"><\/file-include>/g, function (match, p1) {
                return fs.readFileSync('www/sub/' + p1, 'utf8');
            }))
            .pipe(gulp.dest('dist/'))
    )
}

function smoosh() {
    return gulp.src('dist/index.html')
        .pipe(smoosher())
        .pipe(gulp.dest('dist'))
}

function compress() {
    return gulp.src('dist/index.html')
        .pipe(gzip())
        .pipe(gulp.dest('.'));
}

gulp.task(clean);
gulp.task(lint);
gulp.task(Copy);
gulp.task(Copytest);
gulp.task(replaceSVG);
gulp.task(concatApp);
gulp.task(concatApptest);
gulp.task(minifyApp);
gulp.task(smoosh);
gulp.task(clean2);

var defaultSeries = gulp.series(clean,  lint, Copy, concatApp, minifyApp, includehtml, includehtml, smoosh);
//var packageSeries = gulp.series(clean,  lint, Copy, concatApp, minifyApp, smoosh, compress);
var packageSeries = gulp.series(clean,  lint, Copy, concatApp, includehtml, includehtml, replaceSVG,  minifyApp, smoosh, compress, clean2);
var package2Series = gulp.series(clean,  lint, Copy, concatApp, includehtml, includehtml, replaceSVG, smoosh);
var package2testSeries = gulp.series(clean,  lint, Copytest, concatApptest, includehtml, includehtml, replaceSVG, smoosh);

gulp.task('default', defaultSeries);
gulp.task('package', packageSeries);
gulp.task('package2', package2Series);
gulp.task('package2test', package2testSeries);