changing precacheFingerprint does not seem to trigger updating of cache

[liabru]

Description

Changing precacheFingerprint does not seem to trigger updating of cache.

The only reference in the source code to precacheFingerprint I can find is here. I can't see any logic that checks for changes in the fingerprint value to trigger an update.

Am I therefore mistaken in the purpose of precacheFingerprint?

Expected outcome

Changing precacheFingerprint should trigger updating of cache.

Actual outcome

Cache does not get updated with the new files added in precache.

Only when the service worker is destroyed and recreated does the cache update.

Steps to reproduce

Set up a platinum-sw-cache and a cache-config.json file with a list of precache files and a precacheFingerprint.

Load the browser and see the files get cached.

Then add a new entry to the precache file list and change the precacheFingerprint.

Reload the browser and see that the new entry is never added to the cache, even though the precacheFingerprint gets updated in the service worker.

Browsers Affected

All

[petrc]

@liabru What default-cache-strategy are you using on the platinum-sw-cache element? If it is cacheFirst or cacheOnly, the config file containing the precacheFingerprint will load from your local cache and not the updated server version.

https://github.com/PolymerElements/platinum-sw#cacheonly--cachefirst-defaultcachestrategy-considered-harmful