Description

Since function getLanguageMap is now used by both db.js and builtins.js, it would be good to move it to utils.js. Doing so causes the function coverage of builtins.js to slip below 80%, which fails CI, so the move should be accompanied by some new test coverage of builtins.js.

Completion checklist

• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Back-end_Task/Bug_completion_checklist