I'm starting to write some javascript tests and trying to figure out what the best approach is for inspecting the private members of a module constructor. For example, in the sample below i'm using the revealing module pattern to expose the public api to my module. I want to test that privateVar is correctly set during the callback of the $.getJSON ajax request.
The second test it('should update privateVar', ...), doesn't work because myModule.privateVar is (intentionally) not in the public api for the module.
So, my question is, What is the best way to test this kind of behaviour without having to make the privateVar part of the public api? Is there a better way to factor this code for testing, or maybe a way to use something like SinonJs to spy on the private member?
define('myModule',
['jquery'],
function ($) {
var
myVar = "something",
privateVar = "something else",
doSomething = function() {
return $.getJSON('http://myapi.com/do-something', { requestData : "some data" }, function(response){
myVar = response.data.value1;
privateVar = response.data.value2;
});
};
return {
doSomething : doSomething,
myVar : myVar
};
}
);
define('test/test.myModule',
['myModule', 'chai', 'sinon', 'mocha'],
function (myModule, chai, sinon) {
describe("myModule", function() {
var expect = chai.expect;
describe('doSomething', function() {
var value1 = 'value1 value',
value2 = 'value2 value';
beforeEach(function() {
sinon.stub($, 'ajax').yieldsTo('success', {
data : { value1 : value1, value2 : value2 }
});
});
afterEach(function() {
$.ajax.restore();
});
it('should update myVar', function(done) {
myModule.doSomething();
expect(myModule.myVar).to.equal(value1);
done();
});
it('should update privateVar', function(done) {
myModule.doSomething();
expect(myModule.privateVar).to.equal(value2);
done();
});
});
});
}
);
