Allow to cache WAV or FLAC audio in Service Worker

[meduzen]

Depending on the audio capabilities of the device, people might be served FLAC (prefered) or WAV (fallback) sounds.

burokku/src/js/modules/Block/config.js

Line 17 in 96827e0

const format = document.createElement('audio').canPlayType('audio/flac').length > 0 ? 'flac' : 'wav'

However, in the Service Worker cache, the app only caches FLAC.

burokku/src/js/service-worker.js

Lines 18 to 23 in 96827e0

	'sfx/smb-bump.flac',
	'sfx/smb-coin.flac',
	'sfx/smb-1up.flac',
	'sfx/smw-bump.flac',
	'sfx/smw-coin.flac',
	'sfx/smw-1up.flac',

It could be great to cache the supported type.

Proposed approaches:

• There’s no DOM access from a Service Worker, but the HTTP Accept header might be useful, thou it has to be checked if it can be used when building the request (and not when intercepting it) during the caching process.
• Let the app communicate to the Service Worker what’s the supported format, and even let the app send the list of audio files to cache to the Service Worker at request time. As additional benefit, there should be no need to update the Service Worker in order to request an update of audio files and the update flow would be:
  1. Service Worker says “I’m ready” to the app.
  2. The app says “thanks, here are the audio files I need” (with the right format) to the Service Worker.
  3. The Service Worker checks which files are not cached yet, and cache them.