Testing Closure Compiler output under Node.js

Question

I'd like to use Vows to test DOM-free JavaScript code, ideally directly running against the compiled JS. My Vows are written in CoffeeScript, but I'm not sure how to load my JS; I've tried just inlining it using eval:

vows = require "vows"
assert = require "assert"
eval('var e=this;function f(a,g){var c=a.split("."),b=e;!(c[0]in b)&&b.execScript&&b.execScript("var "+c[0]);for(var d;c.length&&(d=c.shift());)!c.length&&g!==void 0?b[d]=g:b=b[d]?b[d]:b[d]={}}function h(a){a.call(e)};(function(){var a;a={};h(function(){a=function(a){this.a=a};a.prototype.b=function(a){return this.a+a.a};f("Cl.LinearExpression",a);f("Cl.LinearExpression.prototype.plus",a.prototype.b)})}).call(this);');

vows
  .describe("Linear Expression")
  .addBatch
    "initialized with a number":
      topic: -> new Cl.LinearExpression 5

      "adds up with scalar": (cle) -> assert.equal 7, cle.plus 2

  .export(module)

but I get "ReferenceError: Cl is not defined". Running the minified JS and new Cl.LinearExpression(5); in a browser console works fine, so the compiled code is okay. What's the best way to load JS into node for testing by Vows?

You can inline JS with backticks, don't use eval for this. – thejh Dec 04 '11 at 18:02 — thejh, Dec 04 '11 at 18:02

score 2 · Answer 1 · answered Dec 04 '11 at 18:04

2

Rather than using eval, why not use Node's require? You can point to either a .js or .coffee file in a relative directory, like so:

Cl = require './cl.js'

In that file, add the line

module.exports = Cl

When the file is required, the return value of the require is the module's exports.

answered Dec 04 '11 at 18:04

Trevor Burnham

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I'd like to avoid having to declare `module.exports` in my compiled JS since I won't be running it as a node library. I did just try that though, and I get the error "Cl is not defined" with the stacktrace showing it from "cl.js". It seems like Node is evaluating the JS somehow differently than Chrome does. – Kevin L. Dec 04 '11 at 18:12
You could also write `this.Cl = ...` (in the outermost scope). That will create a global named `Cl` in the browser, and an export named `Cl` in Node. Use `{Cl} = require './cl'` to access the exported object from you tests. – Trevor Burnham Dec 04 '11 at 18:22
I'm not saying `Cl =` anywhere in my JS---it's being compiled by Google's Closure compiler (with advanced optimizations on) and some magic is going on that seems to work in the browser but not in node. – Kevin L. Dec 04 '11 at 18:32
You might want to do your tests in a browser environment, then. If you use [js-test-driver](http://code.google.com/p/js-test-driver/), you can run browser tests from the command line. – Trevor Burnham Dec 04 '11 at 18:55

score 0 · Answer 2 · answered Dec 04 '11 at 18:02

0

You can use backtick to embed javascript as-is.

`var e=this;function f(a,g){ ... `

answered Dec 04 '11 at 18:02

Brian Genisio

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I didn't know this, thanks. This is nicer to say than `eval()` but I get the same error. – Kevin L. Dec 04 '11 at 18:14

score 0 · Accepted Answer · answered Dec 04 '11 at 19:27

This is a namespace problem; importing with

codes = require "../out/compiled.js"
for k,v of codes
  global[k] = v

adds all of the compiled JS objects to the current namespace, where they can be accessed in Vows.

Unfortunately, I still don't know why using eval() or backticks with the inlined contents of compiled.js doesn't work.

Testing Closure Compiler output under Node.js

3 Answers3