Electric `>` for blank tags (a.k.a fragments)

[goranmoomin]

When using rjsx-mode, I really love the electricity feature of the > key. I have found that, when inserting blank tags (a.k.a fragments), the electric > doesn't work, which makes inserting fragments very tedious. I would like if the electric > works for blank tags too.

[sooqua]

  (defun +javascript-rjsx-electric-gt-a (n)
    (when (and (looking-back "<>")
               (looking-at-p "/>"))
      (save-excursion (insert "<"))))
  (advice-add #'rjsx-electric-gt :after #'+javascript-rjsx-electric-gt-a)

[MageJohn]

I think this advice is probably faster (not that yours is slow, I just spotted some optimisations):

(defun +rjsx-electric-gt-fragment-a (n)
  (if (or (/= n 1) (not (and (eq (char-before) ?<) (eq (char-after) ?/)))) 't
    (insert ?> ?<)
    (backward-char)))
(advice-add #'rjsx-electric-gt :before-while #'+rjsx-electric-gt-fragment-a)

It uses all low level functions defined in C, and it will also completely skip rjsx-electric-gt if it can.