We should deprecate and remove the VueTest extension in favor of CodexExample.

Background

When we were first getting started with Vue.js in MW, we created the VueTest extension as a test-bed and example to show to other WMF developers. Later, we also worked out a somewhat flaky way to get un-merged Codex code inside this extension to allow for testing of upcoming features inside a MediaWiki environment. Finally, we used this extension as a target for the Pixel tool to attempt to catch possible visual regressions caused by changes to Codex components.

However, the developer experience of maintaining this extension has always been poor, and the visual regression tests have suffered from a poor signal-to-noise ratio (making the tests essentially useless – we have too many warnings due to minor, unrelated changes to various other MW skins/extensions/core features). After Codex matured, we created a new stand-alone CodexExample extension that is a better showcase of how to use the features that DST is developing, and the Codex documentation site has also come a long way.

Acceptance Criteria

• Remove VueTest from any WMF-wide Pixel configuration that is currently (see here for an example of how VueTest was first added to Pixel)
• Remove VueTest from BetaLabs (https://en.wikipedia.beta.wmflabs.org/wiki/Special:VueTest/codex)
• Remove VueTest from the WMF branching script (https://gitlab.wikimedia.org/repos/releng/release/-/blob/0ecaf86d7a2176a6dd2c95a640634b500ae72f1c/make-release/settings.yaml#L206)
• Remove all documentation references to VueTest and update the links to point to CodexExample; this search is a good place to start
• Update the MW Page for this extension to indicate that it is no longer active (should probably point folks to CodexExample instead)
• Mark the Gerrit repo as archived/read-only, or even just delete it all together.