Using Protractor in Electron

Question

I am trying to set up unit tests and e2e tests for an application I have running with Electron using Protractor. I've been refering to many different posts (this one did help), but I still get an error I don't understand :

Message:
  Error while waiting for Protractor to sync with the page: "angular could not be found on the window"
Stacktrace:
  undefined

My conf.js file looks like this:

exports.config = {
    directConnect : true,
    seleniumAddress: 'http://localhost:4444/wd/hub',
    baseUrl:"file://home/me/workspace/testing-project/main.js",
    capabilities: {
        browserName: "chrome",
        chromeOptions: {
            binary: "/home/me/.linuxbrew/lib/node_modules/electron-prebuilt/dist/electron",
            args: ["--test-type=webdriver"]
        }
    },
    specs: ['todo-specs.js'],
    onPrepare: function(){
        browser.resetUrl = "file://";
        browser.driver.get("file://");
    }
};

Considering the documentation given on the Protractor website, I am under the impression that I don't need to install anything else (Jasmine for example).
What surprises me is that even though the path to the main.js (that starts the application accordingly to Electron's specifications) is correct, I can't see anything in the Electron window that pops up.
Did any of you encountered this issue? Did you manage to resolve it?

Answer 1

Protractor does not work well with Electron, as it does not have access to the Electron-specific APIs and the renderer cannot be properly controlled. Spectron, on the other hand, is designed specifically for Electron and has an API very similar to Protractor. It gives you access to test both the main and renderer processes at the same time.

I had to copy some code from Protractor to get it to wait for Angular 2 to load properly. (Disregard if you aren't using Angular.) Here is a working example:

const path = require('path');
const electron = require('electron-prebuilt');
var Application = require('spectron').Application
var assert = require('assert')

let appPath = path.join(__dirname, '..', 'dist');

function awaitAngular2(client) {
  client.timeoutsAsyncScript(5000);
  // From: https://github.com/angular/protractor/blob/master/lib/clientsidescripts.js
  // Returns a promise that resolves when all of Angular 2's components are loaded and stable
  return client.executeAsync(function(done) {
    try {
      var testabilities = window.getAllAngularTestabilities();
      var count = testabilities.length;
      var decrement = function() {
        count--;
        if (count === 0) {
          done();
        }
      };
      testabilities.forEach(function(testability) {
        testability.whenStable(decrement);
      });
    } catch (err) {
      done(err.message);
    }
  });
}

describe('application launch', function () {
  this.timeout(10000)

  beforeEach(function () {
    this.app = new Application({
      path: electron,
      args: [appPath]
    });
    return this.app.start().then(() => {
      return awaitAngular2(this.app.client);
    })
  });

  afterEach(function () {
    if (this.app && this.app.isRunning()) {
      return this.app.stop()
    }
  });

  it('shows an initial window', function () {
    return this.app.client.getWindowCount().then(function (count) {
      assert.equal(count, 1)
    })
  });

  it('shows a headline', function () {
    this.app.client.getText('app-banner h1').then(function (bannerText) {
      assert.equal(bannerText, 'Tour of Heroes');
    })
  });
});

If you have multiple .spec files that you want to run automatically, then you can integrate this with Jasmine or Mocha Node.js test runners.

Answer 2

Apparently, using the electron binary is not enough to actually launch your application. However, by building the binary for your application and linking it into your conf.js file works.
I have been able to reduce my file to this:
conf.js

exports.config = {
    seleniumAddress: 'http://localhost:4444/wd/hub',
    specs: ['test-spec.js'],
    capabilities: {
        browserName: "chrome",
        chromeOptions: {
            binary: "./dist/myAwesomeApp/myAwesomeAppBinary"
        }
    },
    onPrepare: function () {
        browser.resetUrl = "file://";
    }
};

By doing it this way, there is no need to describe a baseUrl or to use browser.get() nor browser.driver.get() to start the app in Electron.
However, I would have preferred not to have to build the app binary, but I don't think it is possible for now.