Tests that Input.imeSetComposition works and waits for JavaScript event handlers to finish.
Dispatching event
Initial value:"abcd"

event: keydown
value: abcd
selectionStart: 4
selectionEnd: 4
keyCode: 37
key: ArrowLeft

event: keyup
value: abcd
selectionStart: 3
selectionEnd: 3
keyCode: 37
key: ArrowLeft

event: compositionstart
value: abcd
selectionStart: 3
selectionEnd: 3

event: compositionupdate
value: abcd
selectionStart: 3
selectionEnd: 3

event: beforeinput
value: abcd
selectionStart: 3
selectionEnd: 3

event: input
value: abcｓd
selectionStart: 4
selectionEnd: 4

event: compositionupdate
value: abcｓd
selectionStart: 3
selectionEnd: 4

event: beforeinput
value: abcｓd
selectionStart: 3
selectionEnd: 4

event: input
value: abcすd
selectionStart: 4
selectionEnd: 4

event: compositionupdate
value: abcすd
selectionStart: 3
selectionEnd: 4

event: beforeinput
value: abcすd
selectionStart: 3
selectionEnd: 4

event: input
value: abcすd
selectionStart: 4
selectionEnd: 4

event: compositionend
value: abcすd
selectionStart: 4
selectionEnd: 4