Selenium/Getting Started/Run tests targeting MediaWiki-Docker

This page describes how to run Selenium tests locally on your development install of MediaWiki. This tutorial is based on the setup from MediaWiki-Docker as example, but should work for any other local installation of MediaWiki as well (like MediaWiki-Docker-Dev).

Note that if you use MediaWiki-Vagrant, there is a dedicated page for running Selenium Node.js on MediaWiki-Vagrant.

Advantages

 * It will be fast, since the target machine is local. MediaWiki core Selenium test run takes about 4 minutes on my machine. (As of September 2019.)
 * Works without an internet connection.

Disadvantages

 * You will have to install MediaWiki, Selenium and their dependencies on your machine.
 * You will be executing over 900 JavaScript packages (as of August 2019) directly on your machine with access to all personal/work files.

Prerequisites

 * MediaWiki. We assume you have a MediaWiki-Docker setup. It should be similar for other local MediaWiki installations.
 * Install Google Chrome.
 * Download ChromeDriver and ensure the program is in a folder included in your.
 * Install Node.js and npm.

Environment variables
Ensure the following environment variables are set. Either run this manually from the terminal or, to make it easier for next time, set them from shell configuration file (, ...) which means the variables are always available from any terminal session:

local-charts
If you're not using mediawiki-docker-dev, but for example releng/local-charts, just change the environment variables to point to the correct URL and to use correct credentials.