How can I load a module with RequireJS for testing in a testing framework like Jasmine? - testing

Question

I am new to JavaScript and try to test functions defined in a RequireJS Module.
That means i have some code like this:
define([...], function(...){
var ModuleName = Base.extend({
init: function(){
//some code
};
});
}
Now I want to test the function init().
I load the object from my spec.js, this works:
describe("ModuleName", function(){
var mod = require(['../js/app/ModuleName.js'], function(ModuleName) {});
it("exists", function(){
expect(mod).toBeDefined();
});
});
This passes well.
But when I add this code, it fails:
it("contains init", function(){
expect(mod.init).toBeDefined();
});
I don't understand why.

Answer 1

You're not using RequireJS properly.
The following solution needs the use of beforeAll, which can be added to Jasmine with this package. Your code could be something like this:
describe("ModuleName", function() {
var mod;
beforeAll(function (done) {
// This loads your module and saves it in `mod`.
require(['../js/app/ModuleName'], function(mod_) {
mod = _mod;
done();
});
});
it("exists", function(){
expect(mod).toBeDefined();
expect(mod.init).toBeDefined();
});
});
As I recall, the return value of require called with an array of dependencies is a reference to require itself. So yes, it is defined but, no, it is not the value of the module you were trying to load. To get a module value, you have to do something like I did in the code above.
If your tests happen to be in a RequireJS module, you could also just add the module to be tested to the list of dependencies:
define([..., '../js/app/ModuleName'], function (..., mod) {
describe("ModuleName", function() {
it("exists", function(){
expect(mod).toBeDefined();
expect(mod.init).toBeDefined();
});
});
});
I've used both methods above in different circumstances.
Side note: I've removed the .js from the module name in the code above. You generally do not want to put the .js extension to module names you give to RequireJS.