js--wait-for-matching-output
js--wait-for-matching-output is a compiled Lisp function in `js.el
'.
(js--wait-for-matching-output PROCESS REGEXP TIMEOUT &optional START)
Wait TIMEOUT seconds for PROCESS to output a match for REGEXP.
On timeout, return nil. On success, return t with match data
set. If START is non-nil, look for output starting from START.
Otherwise, use the current value of `process-mark'.