A Kue tutorial using MEAN.io - Part 1

Posted by Cayle Sharrock on April 2, 2015

Setting up the project

I’m going to try out the mean.io tool for scaffolding and managing this demo.

    sudo npm -g install mean-cli
    mean init kueDemo
    cd kueDemo 
    npm install
    bower install

Some interesting things happen here:

  • mean init kueDemo clones the github project for mean.io into this folder
  • npm install runs bower automatically, although the docs indicate that this doesn’t always happen, so run bower anyway to be sure.

Since I now had 2 git repositories nested, I removed the link to mean.io by running

    git remote rm upstream
    rm -fr .git
    cd ..
    git add kueDemo

I’m sure there’s a better way of doing this (that e.g. keeps the link to mean.io as a remote), but I couldn’t figure it out. I think if the mean.io script did a fetch rather than a clone, this might have been easier.

Maybe I can re-add the mean.io as a remote in future and fetch from it to keep the library up to date, I’m not sure.

Installing dev dependencies

One of the dependencies causes an out-of-memory failure on npm. If you go npm install --dev, you run out of memory, at least on a 8GB system.

Checking the basic install

  1. Start Mongo: mkdir /tmp/kueDemo && mongod --dbpath /tmp/kueDemo --smallfiles.

    The --smallfiles option doesn’t use as much disk space, but is less efficient.

  2. Run gulp to run the default task
  3. Open a browser at http://localhost:3000 and you should see the basic scaffolding

Default mean.io app

Looking around

The basic folder structure is pretty deep, so here’s a quick summary:

Folder Filename Description Comment
root gulpfile The task runner definition file Hardly need to modify, if ever; customisation will happen in the gulp/*.js files
  karma.conf.js Karma test config file Looks pretty comprehensive. Can probably leave alone; maybe add more browsers
  mean.js No idea at this point  
  server.js Fires the app up Usually don’t need to touch
config *.js one config file for each type of environment Pretty intuitive as to what you need to edit here
config/middlewares   No idea at this point  
gulp *.js Gulp task definitions; per environment Some customisation will probably be needed; e.g. adding less, moving to jade
packages   This is where the magic happens  
packages/custom   User-generated modules go here use mean package <PKG_NAME> to scaffold packages. For god’s sake, don’t try create them from scratch
packages/custom/MY_PACKAGGE app.js Auto-generated. Usually don’t need to touch

Mocha Test bug

Two days of frustration to figure this out. The mocha tests weren’t running in the mean.io app

The problem lies with the relative paths used to both

  1. glob the model paths
  2. glob the unit tests

The fix:

  • Changing the ../packages/... paths to ./packages/... in gulp/test.js sorts out 2 and partly 1.
  • But now the packages won’t load in require, so You also need to add a few lines in function walk in node_modules/meanio/lib/core_modules/module/util as follows:

     function walk(wpath, type, excludeDir, callback) {
       // regex - any chars, then dash type, 's' is optional, with .js or .coffee extension, case-insensitive
       // e.g. articles-MODEL.js or mypackage-routes.coffee
       var rgx = new RegExp('(.*)-' + type + '(s?).(js|coffee)$', 'i');
       if (!fs.existsSync(wpath)) return;
       fs.readdirSync(wpath).forEach(function(file) {
         var newPath = path.join(wpath, file);
         var stat = fs.statSync(newPath);
         if (stat.isFile() && (rgx.test(file) || (baseRgx.test(file)) && ~newPath.indexOf(type))) {
           var realPath = fs.realpathSync(newPath);                //New line here
           callback(realPath);                                     //Modified line here
         } else if (stat.isDirectory() && file !== excludeDir && ~newPath.indexOf(type)) {
           walk(newPath, type, excludeDir, callback);

Now the tests run:

  27 passing (7s)

In Part 2, we’ll start with some actual coding.