capacitor: bug: wkwebview bouncing issue on iOS 16

Bug Report

Capacitor Version

💊   Capacitor Doctor  💊 

Latest Dependencies:

  @capacitor/cli: 4.2.0
  @capacitor/core: 4.2.0
  @capacitor/android: 4.2.0
  @capacitor/ios: 4.2.0

Installed Dependencies:

  @capacitor/android: not installed
  @capacitor/core: 4.2.0
  @capacitor/ios: 4.2.0
  @capacitor/cli: 4.2.0

[success] iOS looking great! 👌

Platform(s)

• iOS

Current Behavior

The webview bounces when the user slides down the view. I have checked the webview config and bouncing effect is disabled, but it seems it doesn’t work.

Only reproduced on a physical iOS device with iOS 16.

Expected Behavior

The webview shouldn’t bounce when the user slides down the app view.

Code Reproduction

https://github.com/rpanadero/demo-bouncing

Only reproduced on a physical iOS device with iOS 16.

Other Technical Details

npm --version output: 8.19.1

node --version output: v18.9.0

pod --version output (iOS issues only): 1.11.3

Additional Context

This bug was already reported as an iOS 16 issue on Apple forum one month ago, but it seems not to be fixed yet. Maybe, Apple will fix it in some days or months.

https://developer.apple.com/forums/thread/711601

Until Apple fixes the issue, we suggest to apply the workaround commented in this thread because the change is centralized and can be easily reverted when Apple fixes the real issue, if Capacitor team desires. The workaround consist on setting ‘alwaysBounceVertical’ webview property to false. Also, we have tested that the bug is still present on iOS 16 final release and the workaround still works.

We think that this change should be applied on Capacitor core code because this behaviour is undesired for all Capacitor iOS apps. In fact, webview bouncing is already disabled here:

https://github.com/ionic-team/capacitor/blob/76f28e70a5c0a03e4c6b9a93a0c068666a2c38ff/ios/Capacitor/Capacitor/CAPBridgeViewController.swift

https://github.com/ionic-team/capacitor/blob/76f28e70a5c0a03e4c6b9a93a0c068666a2c38ff/ios/Capacitor/Capacitor/CAPBridgeViewController.swift#L286