I'm trying to use browser.storage.onChanged - https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/storage/onChanged to detect when changes are made to browser.storage.local where I save all the preferences for my Safari Web Extension.
This works on Chrome, Firefox, Edge, and Opera. But I can't get it to work on Safari. When I call browser.storage.local.set, the onChanged listener is not called.
Below is the code I'm using to test this in Safari. This has to be in an extension with the Storage permission. - https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions
Given this works in all other browsers and I'm following the documentation, I'm inclined to believe this is a bug in Safari. Am I missing something?
/* Function to handle changes to storage */
function handleChange(changes) {
	for (var key in changes) {
		var storageChange = changes[key];
		console.log('onChanged triggered. '+
				 'Storage key "%s" changed. ' +
				 'Old value was "%s", new value is "%s".',
				 key,
				 storageChange.oldValue,
				 storageChange.newValue);
	}
}
/* Add listener for storage changing */
browser.storage.onChanged.addListener(handleChange)
/* Confirm that the listener has been attached (expect "true" to be returned)*/
browser.storage.onChanged.hasListener(handleChange)
/* Set value for ['testKey] (should trigger onChanged event which calls handleChange) */
browser.storage.local.set({testKey: true}, () => { console.log('Storage updated'); });
/* Get current value for ['testKey] in storage.local, should return {testKey: true}*/
browser.storage.local.get(['testKey'], (result) => { console.log(result); });
/* Change value for ['testKey] (should trigger onChanged event which calls handleChange) */
browser.storage.local.set({testKey: false}, () => { console.log('Storage updated'); });