Jasmine custom matcher with Protractor for checking browser title

Question

I am writing a Jasmine custom matcher to use in a Protractor spec and I want to check that the browser title is equal to some string. I am unable to get this code to work properly and after spending hours debugging it, I can only assume that the browser object is not being accessed inside the matcher function as I expect it to be. When I modify the matcher function to accept browse.getTitle() as the actual argument then it works fine, which leads me to my assumption. Can anyone find the issue here and explain it to me?

beforeEach(function() {
    jasmine.addMatchers({
        toBeOnPage: function(util, customEqualityTesters) {
            return {
                compare: function(actual, expected) {
                    var result = {};
                    result.pass = actual.getTitle() === expected.title;
                    return result;
                }
            };
        }
    });
});

var homepage = { url: 'Homepage URL', title: 'Homepage Title' };

describe('regression:', function() {
    it('homepage loads successfully', function() {
        browser.get('http://localhost/#/home');
        expect(browser).toBeOnPage(homepage);
    });
});

Answer 1

The problem is that getTitle() returns a promise. Resolve it:

beforeEach(function() {
    jasmine.addMatchers({
        toBeOnPage: function(util, customEqualityTesters) {
            return {
                compare: function(actual, expected) {
                    return {
                         pass: actual.getTitle().then(function (title) {
                              return title === expected.title;
                         });
                    };
                }
            };
        }
    });
});