Expose object fron Angularjs App to Protractor test - angularjs

Question

I am writing end-to-end tests for my AngularJS-based application using Protractor. Some cases require using mocks to test - for example, a network connection issue. If an AJAX request to server fails, the user must see a warning message.
My mocks are registered in the application as services. I want them to be accessible to the tests to write something like this:
var proxy;
beforeEach(function() { proxy = getProxyMock(); });
it("When network is OK, request succeeds", function(done) {
proxy.networkAvailable = true;
element(by.id('loginButton')).click().then(function() {
expect(element(by.id('error')).count()).toEqual(0);
done();
});
});
it("When network is faulty, message is displayed", function(done) {
proxy.networkAvailable = false;
element(by.id('loginButton')).click().then(function() {
expect(element(by.id('error')).count()).toEqual(1);
done();
});
});
How do I implement the getProxyMock function to pass an object from the application to the test? I can store proxies in the window object of the app, but still do not know how to access it.

Answer 1

After some reading and understanding the testing process a bit better, it turned to be impossible. The tests are executed in NodeJS, and the frontend code in a browser - Javascript object instances cannot be truly shared between two different processes.
However, there is a workaround: you can execute a script inside browser.
First, your frontend code must provide some sort of service locator, like this:
angular.module('myModule', [])
.service('proxy', NetworkProxy)
.run(function(proxy) {
window.MY_SERVICES = {
proxy: proxy,
};
});
Then, the test goes like this:
it("Testing the script", function(done) {
browser.executeScript(function() {
window.MY_SERVICES.proxy.networkAvailable = false;
});
element(by.id('loginButton')).click().then(function() {
expect(element.all(by.id('error')).count()).toEqual(1);
done();
});
});
Please note that when you use executeScript, the function is serialized to be sent to browser for execution. This puts some limitations worth keeping in mind: if your script function returns a value, it is a clone of the original object from browser. Updating the returned value will not modify the original! For the same reason, you cannot use closures in the function.