Scaffolds for adding browser/DOM testing to setup

[msecret]

In order for developers to run their front end unit tests in an actual browser to leverage all the browser APIs, there should be a scaffold for setting up a browser for testing.

[shawnbot]

Yes! I've had lots of success with webdriver.io, and I particularly like that it works with mocha's test APIs. It would be really awesome if we could find a way to make this (optionally) work with jsdom so that folks don't have to get Selenium working locally just to run the tests. In other words:

• write mocha tests that work without Selenium (e.g. with --require jsdom-global/register)
• configure webdriver.io to run the same tests but in a variety of browsers, either locally (for testing with PhantomJS or Chrome) or on Sauce Labs

[msecret]

I like the idea of allowing either jsdom or selenium. I'd always opt for jsdom first and move to selenium if my code is really complex (which often breaks in jsdom)

[shawnbot]

Hmmm... Now that I think about it, I'm not sure if that level of abstraction is possible. Browser tests usually involve lots of serial async actions over the Selenium protocol, whereas jsdom can do everything synchronously. webdriver.io's v4 upgrade guide explains how you can write synchronous tests that are transformed to async at runtime, but I think that in order to write tests that work in both jsdom and webdriver.io, you'd need to write some sort of jsdom → webdriver.io API adapter.

So maybe jsdom isn't the thing here, but the default is PhantomJS, which is as "modern" as we probably need it to be in terms of native API support and does its own Selenium protocol communication so you don't have to install Selenium server and drivers for local browsers just to run the tests?