gulp source map with babel, uglifyjs, ngAnnotation.

gulpfile.js

var gulp = require('gulp');
var gutil = require('gulp-util');
var concat = require('gulp-concat');
var rename = require('gulp-rename');
var replace = require('gulp-replace');
var sh = require('shelljs');

var sourcemaps = require('gulp-sourcemaps');
var babel = require('gulp-babel');

// new
var del = require('del');
var ngAnnotate = require('gulp-ng-annotate');
var uglify = require("gulp-uglify");
var runSequence = require('run-sequence');

var paths = {
  dist: ['./www'],
  scripts: [
    './src/app/**/*.js'
  ]
};

var files = {
  jsbundle: 'app.bundle.min.js'
};

gulp.task('scripts-sourcemap', function () {
  return gulp.src(paths.scripts)
    .pipe(sourcemaps.init())
    .pipe(ngAnnotate({
      remove: true,
      add: true,
      single_quotes: true
    }))
    .pipe(babel({
      presets: ['es2015']
    }))
    .pipe(uglify())
    .pipe(concat(files.jsbundle))
    .pipe(sourcemaps.write('.'))
    .pipe(gulp.dest(paths.dist + '/app'))
    .on('error', function (err) {
      gutil.log(gutil.colors.red('[Error]'), err.toString());
      this.emit('end');
    })
});