Skip cache on certain errors on network-first requests

[BowlingX]

Hi,
thank's a lot for this plugin :).
I'm wondering If it's possible to return the cached result only on certain error codes or even only if the client is offline. Right now, any error the server throws during fetch < 500 (like != ok -> https://github.com/NekR/offline-plugin/blob/master/src/misc/sw-template.js#L378) or general errors: https://github.com/NekR/offline-plugin/blob/master/src/misc/sw-template.js#L391 are forwarded to the cached version.

Could we make this configurable? I could properly provide a pull-request.

[NekR]

@BowlingX that would be a good feature to have, but I'm not sure how API for that would look like. Do you have any ideas?

[GGAlanSmithee]

@BowlingX regarding returning cached assets only if the client is offline, you can do that already with responseStrategy

[BowlingX]

@GGAlanSmithee, At least network-first (see function networkFirstResponse) will always load from cache when != ok.

@NekR maybe something like:

shouldServeFromCache: (response:Object, cacheUrl:string, url:string) => boolean defaults to (response) => !response.ok

But I will think about something.