Testing AngularJS app with Protractor in multiple browsers (OS X)

Different browsers have different quirks, so let's try to run e2e tests in multiple major browsers.
We can't run IE in OS X, Opera is customized Chrome, so we need: Chrome, Safari,  Firefox.

Protractor has option to run specs in multiple browsers, called multiCapabilities.
By default all browsers run tests simultaneously, but in my experience it leads to errors ("failed expectations"), because sometimes tests trying to fulfill same records and it leads to conflicts.
To run tests in browsers consecutive, we can use "maxSessions: 1" in Protractor config.
So result is:

multiCapabilities: [
{
'browserName': 'chrome'
}
, {
'browserName': 'safari'
}
, {
'browserName': 'firefox'
}
],
maxSessions: 1,

If you use browserSync to run app locally, add "ghostMode: false" in browserSync config to avoid conflicts in launched versions of app when testing.

But software is often more complicated than we expect.

First: we can't run actual version of Firefox on OS X, even with new Selenium drivers.

Bug has status "Fixed" but nobody cares about regression. Update: to run tests in Firefox, use Protractor 1.8+, it will install Selenium 2.45, where bug is fixed.

So now we have Chrome and Safari in list.

Safari don't want to run too, hehe :) But it's fixable at least, thanks to this detailed answer.

Get actual version of Selenium driver jar here: http://central.maven.org/maven2/org/seleniumhq/selenium/selenium-safari-driver/, 

rename extension to .zip, 

unzip file 

and then in folder 'org/openqa/selenium' find file 'SafariDriver.safariextz' (it's not random letters :)) and double-click it.

After that, we can run tests in Safari, hurray!

And it's not the end of this story :)

Selenium can't navigate in browsing history of Safari (known issue), so if you use 

browser.navigate().back();

replace it to:

// before changing URL

var prevUrl = browser.getCurrentUrl();

// here some changing URL action, maybe click()

// ...

// and then

browser.navigate().to(prevUrl);

It's pretty obvious fix.

And now we can run Protractor tests in Chrome and Safari consecutive. It took few hours of my time to find all these fixes and workarounds, so I hope this article will help somebody to save time :)