beforeinput event is not supported in Safari

Phenomenon

The beforeinput event, which is crucial for intercepting and modifying input before it’s committed to the DOM, is not supported in Safari. This makes it difficult to implement custom input handling that works across all browsers.

Reproduction example

1. Create a contenteditable div.
2. Add an event listener for the beforeinput event.
3. Type some text.
4. Observe whether the beforeinput event fires.

Observed behavior

• In Safari on macOS, the beforeinput event does not fire.
• Event listeners for beforeinput are never called.
• Alternative approaches must be used, but they are less reliable.

Expected behavior

• The beforeinput event should be supported in all modern browsers.
• The event should fire before input is committed to the DOM.
• It should provide a way to prevent or modify the default input behavior.