Task Runners pt.4: Another Gulp


Last time, we covered how to install, configure, and use gulp to automate some useful tasks and how gulp is differentiated from Grunt. Some of those differences were specific to "piping" task actions through each other, is a bit more succinct, embraces streams which let the async capabilities take off, and the available plugins make the json-server back-end mock (or reverse proxy to Domino Designer local web preview or development server) easy to invoke for continuous use while in ongoing development, or for one-off build commands (gulp vs gulp build, or other individual tasks).

Taking It Further

Last time I attempted to answer the question of "where is this all going?" with a focus on answering some of the greater automation concerns that have been on my mind. In fact, I've recently been making greater strides towards automating XPages application builds in no small part thanks to the Swiper and BuildXPages efforts by Cameron Gregor. Cameron has been helpful in answering the occasional question as well, adding him to the list of people I would enjoy purchasing a beverage for in-person, should the opportunity arise.


Here's the link to my current Gulpfile.js as of this writing.

Tasks Galore

Moving ahead, it would be remiss if I didn't cover some more of my Gulpfile.js, so in the effort of completing the immediate picture, here's a collection of more of my tasks, broken apart for description.


The only thing special here is the configuration in the "server" handle to load the specifics to the json-server setup, covered previously.

// grab our packages
var gulp = require('gulp'),
gutil = require('gulp-util'),
jshint = require('gulp-jshint'),
concat = require('gulp-concat'),
sourcemaps = require('gulp-sourcemaps'),
jsonServer = require('gulp-json-srv'),
minify = require('gulp-minify-css'),
rename = require('gulp-rename'),
minifyHTML = require('gulp-minify-html'),
inject = require('gulp-inject'),
del = require('del'),
runSequence = require('run-sequence'),
uglify = require('gulp-uglify'),
ngAnnotate = require('gulp-ng-annotate'),
server = jsonServer.start({
// config the json-server instance
data: 'db.json',
id: 'unid',
rewriteRules: {
"/xsp/houses": "/houses",
"/xsp/:houses/:id": "/:houses/:id",
"/xsp/characters": "/characters",
"/xsp/:characters/:id": "/:characters/:id"
deferredStart: true
compress = require('compression'),
browserSync = require('browser-sync').create();


As previously covered.

// configure the jshint task
gulp.task('jshint', function() {
return gulp.src(['./src/js/*.js'])
// ideally I'll just clean this up, but leaving here for demonstrative purposes
'-W033': true, // mising semicolon
'-W041': true, // use 'x' to compare with 'y'
'-W004': true, // x already in use
'-W014': true // bad line breaking before '||'
view raw 02-jshint.js hosted with ❤ by GitHub

Build JS

This is what builds the source files into a single app scripts.js (it's a Single Page Application output, in a multi-page app we would follow a per-page requirements pattern), which is concatenated and uglified. The special note here is that ngAnnotate package is used to account for the AngularJS dependency injection; this was surprisingly easy to set up the first time. I've left in a comment showing how one could not uglify while in development based on an environment variable.

// build dist JS assets
gulp.task('build-js', function() {
return gulp.src('./src/js/*.js')
//only uglify if gulp is ran with '--type production'
//.pipe(gutil.env.type === 'production' ? uglify() : gutil.noop())
//.on('error', notify.onError("Error: <%= error.message %>"))
view raw 03-buildJs.js hosted with ❤ by GitHub

CSSMin and Optimize HTML

Concatenation and minification of CSS and separately optimizing of HTML assets (white space removal, unnecessary comments, etc.).

gulp.task('cssmin', function(){
.pipe(minify({ keepBreaks: false }))
.pipe(concat('style.min.css')) // combines into single minified CSS file
// I named this task poorly, it removes white-space
// and doesn't "minify"
gulp.task('minify-html-partials', function(){
var opts = {
conditionals: true,
spare: true
return gulp.src('./src/partials/*.html')

Dynamic Injecting Assets Into Index

This is one of the more interesting tasks, as it injects into the final built index.html, making re-defining paths to development versus production built assets automated (after the first-time config).

gulp.task('index', function(){
var target = gulp.src('./src/index.html');
var sources = gulp.src([
], { ignorePath: 'public', read: false });
return target.pipe(inject(sources, { ignorePath: 'public' }))


Before each generation, we need to clean the final build path of previous versions, using clean.

gulp.task('clean', function () {
return del([
// we don't want to clean this file though so we negate the pattern
view raw 06-clean.js hosted with ❤ by GitHub


Watch is the task that "watches" for file changes in the specified (source) files and triggers additional behavior as-needed.

// configure which files to watch and what tasks to use on file changes
gulp.task('watch', function() {
gulp.watch('./src/js/*.js', ['jshint','browser-sync-reload']);
gulp.watch(['db.json'], function(){ server.reload(); });
gulp.watch('./src/css/*.css', ['cssmin']);
gulp.watch('./src/partials/*.html', ['minify-html-partials'])
view raw 07-watch.js hosted with ❤ by GitHub


I've defined the start and reload actions as separate tasks, making it easy to trigger a re-load on any other task.

// starts the json-server instance
gulp.task('serverStart', function(){ server.start(); });
// reload the json-server instance, and its assets
gulp.task('serverReload', function(){ server.reload(); });


Browser-sync is initialized with a proxy to my localhost on port 3000, json-server, with a port configuration for the remote debugging to a different port; the default of 8080 was interfering with a Jenkins instance on a machine I was working from. Additionally, I have another reload task for easier hooking from other tasks.

// loading browser-sync as a proxy, must load after json-server
gulp.task('browser-sync', function() {
proxy: {
target: "http://localhost:3000/",
middleware: [compress()]
ui: {
weinre: {
port: 9090
// reload browserSync
gulp.task('browser-sync-reload', function(){

Build and Default

My build task generates the assets and performs all the tasks I would want done if I were to do so without having a local mocked preview; aka- just build the assets and no funny business. This also makes it easier long-term to perform such tasks in a build pipeline. The difference in this task is that, since some of the tasks depend on others finishing before they run, I'm using run-sequence to achieve that. For the default, where I expect the local preview and browser-sync to run, is added to the 'build' task.

// generic build, assuming we don't want the preview
gulp.task('build', function(){
// define the default task and add the watch task to it
gulp.task('default', ['build', 'watch', 'serverStart','browser-sync']);


As you can see, things have gotten more complex, but that's only because I wanted to do more things with gulp. I've found that the more I use Grunt and gulp, the more I want to keep a "grab bag" of likely tasks that require little additional fiddling, which speaks to the benefits of keeping to a convention of project structure between projects.

I will be working the themes of testing and hooking into build automation further down the road. These topics also play directly into my IBM Connect 2016 session, which I hope to see everyone at. I'll have a proper session announcement post later on as well. Until then, 🍻!


I've also taken my working copy of the front-end assets I've been testing with along with my Gruntfile.js, gulpfile.js, and package.json and put them into a GitHub repository.