CODEWITHSUNDEEP
unit-testingpromisemocha.js
maham.shahid
maham.shahid

Reputation: 301

Error Occurs in Testing Promises With Mocha

I'm using mocha and chai to perform some unit testing of an AngularJS service. The service has different functions and each function returns a promise.

The problem I'm facing is that the test is not waiting for the promise value to be resolved before asserting. I know done() callback can be used with mocha. So, I've tried using that. But that's giving me an error as well. Here's the code:

describe('Service Test', function() {

    var factory;
    beforeEach(module('Test'));
    beforeEach(inject(function(_QueryService_){
            factory = _QueryService_;
        })
    );
    it('should check simpleQuery method',function(done){

        var promise = factory.query("args");
        var value;
        promise.then(function(data){
            value = data;
            assert.equal(1,2);
            done();
        }, function(error){
            assert.equal(3,4);
            done();
        });
    });
});

So the problem right now is that the test is not failing (as it should). Instead, it just times out and gives me an error:"timeout of 2000ms exceeded. Ensure the done() callback is being called in this test"

And if I don't include done callback then the test passes because it doesn't even evaluate the condition.

Can someone suggest a fix? Thanks!

Upvotes: 0

Views: 120

Answers (1)

Patrick Motard
Patrick Motard

Reputation: 2660

I do testing in Node.js using chai and mocha. The majority of what I test are promises. Here is some sample code to get you started.

var chai = require('chai'),
    expect = chai.expect;

chai.use(require('chai-things'))
    .use(require('chai-as-promised'));
chai.should();

describe(' Testing:', function() {
    describe('#getBlah', function() {
        describe('If blah', function() {
            it('Should should blah', function() {
                return service.getBlahAsync(foo, bar).should.eventually.have.length(0);
            });
        });

describe('If blahblah', function() {
    it('Should should blahblah', function() {
        return service.getBlahAsync(foo, bar).should.eventually.all.have.property(foobarbaz);
    });
});

You can also do things like increasing the timeout duration of the test. Documentation for that can be found here.

Upvotes: 1

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