The Selenium webdriver is difficult to use, and easy to misuse. To help
use the driver and make it easier to maintain our e2e tests, all driver
interactions are now performed via a `driver` module. This is basically
a wrapper class around the `selenium-webdriver` that exposes only the
methods we want to use directly, along with all of our helper methods.
Typically the fullscreen UI will open upon installation, though this
behaviour was suppressed in development. This was dealt with in the e2e
tests by waiting for it to open, then closing it.
Instead this behaviour is now suppressed for test builds as well.
* Improve `openNewPage` helper function
The two delays were removed, and the window handle for the new page is
now returned. This was made possible with the new `newWindow` function
added in `v4.0.0-alpha.3` of `selenium-webdriver`.
* Replace recursion with loops
This should result in far more pleasant stack traces for any
exceptions in these functions. It might also be faster. These functions
seem easier to understand as loops as well.
* Remove unused string parameter
The `closeAllWindowHandlesExcept` function has been simplified by
removing a branch that handles the case where the `exceptions`
parameter given is a string. That parameter is never a string.
Update `selenium-webdriver` to v4.0.0-alpha.5. Despite the fact that
this version has "alpha" in the name, the maintainer of
`selenium-webdriver` has described this release as stable [1].
A few APIs were removed or changed in v4, which required changes to our
Firefox webdriver.
The port used for webdriver communication can now be specified
manually. This was required to ensure the threebox tests kept working,
because they used two different driver instances. This new version of
`selenium-webdriver` now uses the same port for each instance of the
webdriver (unlike the old version, which generated a new port for each
one), so it was necessary to manually specify the port to prevent the
same port from being used for both instances.
`chromedriver` required an update, as the version we were using was not
compatible with the new W3C WebDriver protocol. I've updated
`geckodriver` as well, just to bring it in line with the version of
Firefox we are using.
[1]: https://github.com/SeleniumHQ/selenium/issues/5617#issuecomment-373446249