Filter input events of type insertCompositionText for Safari

[ddayguerrero]

Fixes #38

Changes

• Keeping in mind W3C's UI keyboard event table these changes filters out input events of type insertCompositionText on Safari.

Why introduce these changes?

• Improve UX for Safari users with input sources which utilizes IME input (e.g. Hirgana)
• Normalize inputTypes for input events for Safari.

How is this achieved?

• End function execution on input events with inputType insertCompositionText on _eventNormalize()

• ⚠️ For Safari, these changes will not format full-width input characters on the fly. Instead, the target element's input value will only be formatted on the compositionEnd event type. This introduces a smaller and less significant compromise on the UX, but ultimately solves the more important issue with inconsistent values between IME and the input value.

Additional Information

• Safari handles Input Method Editors differently from other browsers. When surfacing input UI keyboard events, the data attribute holds different values from other non full-width input sources. Moreover, data is read-only.

• While Mac OS allows users to disable IME editor through the Live Conversion option in keyboard preferences, input events of type insertCompositionText events are still raised and captured by the browser.

Testing

Typed in full-width character keyboard inputs (e.g. Hiragana) and made sure validation and formatting works as expected:

Desktop 🖥(Mac OSX High Sierra):

• Same behaviour on latest Chrome, Firefox ✅
• Latest Safari ✅

Mobile 📱:

• iOS Safari ✅

[arthurgouveia]

Tested locally and also working nicely 👍