To manually test, press and hold down 'a' and select one of the accented characters."
You should observe a pair of beforeinput/input events for both 'a' and the replacement accented character."
Importantly, the inputType of these four events should be 'insertReplacementText'."
Then insert a single emoji character. You should observe beforeinput/input events for the inserted emoji."
Importantly, the inputType of these two events should be 'insertText'."

(1) Typing 'a'...
(editable): type=beforeinput, inputType=insertText, data=a, dataTransfer=null
(editable): type=input, inputType=insertText, data=a, dataTransfer=null
The value of the input is now: a
(2) Replacing 'a' with 'b'...
(editable): type=beforeinput, inputType=insertReplacementText, data=b, dataTransfer=null
(editable): type=input, inputType=insertReplacementText, data=b, dataTransfer=null
The value of the input is now: b
(3) Inserting 'c' after 'b'...
(editable): type=beforeinput, inputType=insertText, data=c, dataTransfer=null
(editable): type=input, inputType=insertText, data=c, dataTransfer=null
The value of the input is now: bc
(4) Selecting all and replacing with 'd'...
(editable): type=beforeinput, inputType=insertReplacementText, data=d, dataTransfer=null
(editable): type=input, inputType=insertReplacementText, data=d, dataTransfer=null
The value of the input is now: d