Selenium/Getting Started/Run tests using Fresh

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.

Advantages

 * It will be fast, since the target machine is local. MediaWiki core Selenium test run takes about 2 minutes on my machine. (As of October 2019.)
 * Works without an internet connection.
 * Doesn't require installing Vagrant.
 * Doesn't require installing ChromeDriver or FFmpeg (compared to bare installs).
 * Doesn't require executing npm packages directly on your machine (which is scary).

Disadvantages

 * You need to have Docker installed.

Prerequisites

 * MediaWiki. We assume you have a MediaWiki-Docker setup. It should be similar for other local MediaWiki installations.
 * Docker. See Docker CE for Linux, Docker for Mac, or Docker for Windows.
 * Install the Wikimedia Fresh CLI for Docker.

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:

Run Selenium tests
Next, navigate to where you have the MediaWiki core repository and start a Fresh session (let it see environment variables, and grant networking to access for your MediaWiki install):

The first time (or after updating MediaWiki), install the npm packages used by MediaWiki's browser tests:

Run Chromedriver:

And finally, run the tests: