minify everything inside bower_components

gulpfile.js

var gulp = require('gulp');
var del = require('del');
var runSequence = require('run-sequence');
// var minifyHTML = require('gulp-minify-html');
var minifyInline = require('gulp-minify-inline');
var size = require('gulp-size');
var uglify = require('gulp-uglify');

var htmlmin = require('gulp-htmlmin');
var options = {
  collapseWhitespace: true,
  removeComments: true,
  removeAttributeQuotes: true,
  removeRedundantAttributes: true,
  useShortDoctype: true,
  removeEmptyAttributes: true,
  removeScriptTypeAttributes: true,
  removeStyleLinkTypeAttributes: true,
  removeOptionalTags: true
};

gulp.task('default', function() {
  console.log('Gulp is up and running.');
  runSequence(
    'clean',
    'minifyBowerComponents',
    'uglify',
    'copy'
  );
});

gulp.task('minify', function() {
  return gulp.src([
    '*.html',
    '!index.html'
  ]).pipe(minifyInline())
    .pipe(htmlmin(options))
    // .pipe(minifyHTML())
    .pipe(gulp.dest('dist'));
});

gulp.task('uglify', function() {
  return gulp.src([
    'bower_components/**/*.js',
    '!bower_components/lodash/**/*.js',
    '!bower_components/webcomponentsjs/**/*.js',
    '!bower_components/**/demo/**/*.js',
    '!bower_components/**/test/**/*.js',
  ]).pipe(size({
    pretty: !0,
    title: 'Before uglify...'
  })).pipe(uglify())
    .pipe(size({
      pretty: !0,
      title: 'After uglify...'
    }))
    .pipe(size({
      pretty: !0,
      title: 'After uglify and minify...',
      gzip: !0
    }))
    .pipe(gulp.dest('dist'));
});

gulp.task('copy', function() {
  return gulp.src([
    'bower_components/lodash/**/*.min.js',
    'bower_components/webcomponentsjs/**/*.min.js',
  ], { base: 'bower_components' })
      .pipe(size({
        pretty: !0,
        title: 'Before copy...',
        gzip: !0
      })).pipe(gulp.dest('dist'));
});

gulp.task('minifyBowerComponents', function() {
  return gulp.src([
    'bower_components/**/*.html',
    '!bower_components/**/index.html',
    '!bower_components/**/demo/**/*.html',
    '!bower_components/**/test/**/*.html',
  ]).pipe(size({
      pretty: !0,
      title: 'Before minify...'
    }))
    .pipe(minifyInline())
    .pipe(htmlmin(options))
    // .pipe(minifyHTML())
    .pipe(size({
      pretty: !0,
      title: 'After minify...'
    }))
    .pipe(size({
      gzip: !0,
      pretty: !0,
      title: 'After minify and gzip...'
    }))
    .pipe(gulp.dest('dist'));
});

gulp.task('clean', function() {
  return del([
    'dist'
  ]);
});