Run browser tests with Fresh

Watch it in action

A recorded Fresh browser test

Fresh runs Node.js and browser tools in a container, with your MediaWiki checkout mounted at /var/www/html/w. Run the commands below from the checkout directory after installing a wiki.

Install dependencies and run a test

mw dev mediawiki fresh npm ci
mw dev mediawiki fresh npm run selenium-test -- -- --spec tests/selenium/specs/recentchanges.js

For connection defaults, argument forwarding, and recording behavior, read mw dev mediawiki fresh --help. Override the development account when testing another user, as shown below.

To inspect the container or override an environment variable for one command:

mw dev mediawiki fresh bash
mw dev mediawiki fresh MEDIAWIKI_USER=OtherAdmin npm run selenium-test -- -- --spec tests/selenium/specs/recentchanges.js

Record a Selenium video

With a checkout that supports wdio-mediawiki video recording, use the shortcut after installing dependencies with mw dev mediawiki fresh npm ci:

mw dev mediawiki fresh record tests/selenium/specs/recentchanges.js

Omit the spec to record the full Selenium suite, running one spec at a time:

mw dev mediawiki fresh record

The explicit equivalent for a single spec is:

mw dev mediawiki fresh npm run selenium-test -- -- --recordVideo --useBrowserHeadless=false --maxInstances=1 --spec tests/selenium/specs/recentchanges.js

The bundled browser image provides Xvfb and ffmpeg. The runner starts its virtual display and recorder automatically; no manual Xvfb session is needed. Recording needs a non-headless browser inside that virtual display, so keep --useBrowserHeadless=false.

The first -- passes the remaining flags through the CLI; the second forwards them through npm to WebdriverIO. Keep both when passing test-runner flags.

Videos and reports normally appear in tests/selenium/log/ in your host checkout. Check for a newly written .mp4 file after the run. A project’s WebdriverIO configuration can change the output directory; LOG_DIR sets the default runner’s log directory. Older checkouts may lack recording support or require their own setup; consult their Selenium README.

Recording is opt-in. Omit the recording options for normal browser tests. See Fresh and your checkout’s tests/selenium/README.md for more options.

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Read this guide offline with mw help guides dev fresh.