C[omp]ute

From: andrew cooke <andrew@...>

Date: Fri, 17 Feb 2012 20:19:21 -0300

I am trying to get started with Javascript on the command line.  I want to
write a "significant" amount of code, and so thought maybe I should be trying
to develop using nodejs to run tests etc (even though the code will finally
run in a browser).

But I am having a hard time finding good, introductory information on how to
do this, so decided to write some notes here in case they might help others.

This is where I am: I can define modules and run tests.  In addition, I am
using requirejs to load modules, which I believe will carry across to working
in the browser - http://requirejs.org/

This is what I did:

 - Add the nodejs plugin to Intellij Idea (most of what is described here is
   independent of using Intellij Idea, but if you use it, you need this).

 - Install nodejs and npm (for OpenSuse the nodejs package installs both).

 - npm is the node package manager and works something like easy_install for
   Python.  You can install files globally, but it seems more sensible to run
   it locally in the project directory).  If you do that (as I do here) you
   need to add the file node_modules/.bin to your path (where node_modules is
   a directory that will appear when you run npm below).

 - Create you project directory.

 - In that directoryUsing npm install the libraries you want:
     npm install underscore
     npm install requirejs
     npm install benchmark
     npm install nodeunit
     npm install amdefine
     npm install assert

 - Also create src and test subdirectories.

 - In the src directory create a file called utils.js (for example).  This is
   your first module.  The contents are (for example):

     if (typeof define !== 'function') {
	 var define = require('amdefine')(module);
     }

     define(['underscore'], function () {

	 "use strict";

	 if ('function' !== typeof Object.beget) {
	     Object.beget = function (o) {
		 var f = function () {
		 };
		 f.prototype = o;
		 return new f();
	     };
	 }

     });

   where the first three lines are described at
   http://requirejs.org/docs/node.html#nodeModules and the next block defines
   your module (which unusually doesn't have any contents, but does make
   global changes to Javascript).

 - In the test directory create file called utils.js (for example) with your
   tests:

     if (typeof define !== 'function') {
	 var define = require('amdefine')(module);
     }

     define(['underscore'], function () {

	 "use strict";

	 return {
	     test1: function(test) {
		 test.equals(1,1);
		 test.done();
	     }
	 }


     });

   where I am using nodeunit because it is supported by Intellij.
   Alternatively, you could use mocha.  For that case see my question here
   http://stackoverflow.com/questions/9303945

 - With that you can now test from the command line (don't forget to cmodify
   PATH as described above:

     > nodeunit test

     utils.js
     / test1

     OK: 1 assertions (14ms)

   where I've replace a cute tick mark with a "/" that is more likely to
   display on my antique blog.

 - Alternatively, you can run the tests in Intellij.  Go to "Edit
   configurations" and add a nodeunit config.  Note that there is a strange
   bug - if you select the files from the file selector then you need to make
   the path in the last textbox relative (delete the leftmost part of the
   path).  See http://youtrack.jetbrains.com/issue/IDEA-81566

OK, that's as far as I have got.

Andrew