The upstream autoCloseTags extension works great (and by default) for Vue, HTML, XML, etc. It would be great to have the same functionality for the mediawiki mode.
In particular, this is deemed valuable to users of the Math extension. Quoting from Community Wishlist/W141:
Writing <math>x</math> quickly gets cumbersome for simple variables that you need to mention multiple times per sentence, so articles tend to use ''x'' instead.
The number of keystrokes could be reduced dramatically if we had auto-closing of tags.