Using Gulp to Concatenate and Uglify files

Question

I\'m trying to use Gulp to:

1. Take 3 specific javascript files, concatenate them, then save the result to a file (concat.js)
2. Take this concatenated file

Answer 1

we are using below configuration to do something similar

    var gulp = require('gulp'),
    async = require("async"),
    less = require('gulp-less'),
    minifyCSS = require('gulp-minify-css'),
    uglify = require('gulp-uglify'),
    concat = require('gulp-concat'),
    gulpDS = require("./gulpDS"),
    del = require('del');

// CSS & Less
var jsarr = [gulpDS.jsbundle.mobile, gulpDS.jsbundle.desktop, gulpDS.jsbundle.common];
var cssarr = [gulpDS.cssbundle];

var generateJS = function() {

    jsarr.forEach(function(gulpDSObject) {
        async.map(Object.keys(gulpDSObject), function(key) {
            var val = gulpDSObject[key]
            execGulp(val, key);
        });

    })
}

var generateCSS = function() {
    cssarr.forEach(function(gulpDSObject) {
        async.map(Object.keys(gulpDSObject), function(key) {
            var val = gulpDSObject[key];
            execCSSGulp(val, key);
        })
    })
}

var execGulp = function(arrayOfItems, dest) {
    var destSplit = dest.split("/");
    var file = destSplit.pop();
    del.sync([dest])
    gulp.src(arrayOfItems)
        .pipe(concat(file))
        .pipe(uglify())
        .pipe(gulp.dest(destSplit.join("/")));
}

var execCSSGulp = function(arrayOfItems, dest) {
    var destSplit = dest.split("/");
    var file = destSplit.pop();
    del.sync([dest])
    gulp.src(arrayOfItems)
        .pipe(less())
        .pipe(concat(file))
        .pipe(minifyCSS())
        .pipe(gulp.dest(destSplit.join("/")));
}

gulp.task('css', generateCSS);
gulp.task('js', generateJS);

gulp.task('default', ['css', 'js']);

sample GulpDS file is below:

{

    jsbundle: {
        "mobile": {
            "public/javascripts/sample.min.js": ["public/javascripts/a.js", "public/javascripts/mobile/b.js"]
           },
        "desktop": {
            'public/javascripts/sample1.js': ["public/javascripts/c.js", "public/javascripts/d.js"]},
        "common": {
            'public/javascripts/responsive/sample2.js': ['public/javascripts/n.js']
           }
    },
    cssbundle: {
        "public/stylesheets/a.css": "public/stylesheets/less/a.less",
        }
}