Hosting multiple service workers on the same origin deletes the cache from other subdirectories

[BenLubar]

Library Affected:
workbox-precaching

Browser & Platform:
all browsers

Issue or Feature Request Description:
I have multiple web apps hosted on the same domain that each have a service worker set up to allow the use of the app offline. For example, https://benlubar.github.io/cmv2mp4/ and https://benlubar.github.io/df-ai/plan-editor/.

Setting a different cache name prefix on each only affects the name of the cache, which already contains the URL of the directory where the service worker is hosted. The IndexedDB is always named workbox-precaching and contains no information about which subdirectory the service worker is hosted in.

[jeffposnick]

Thanks for reporting—that does seem like and oversight.

CC: @gauntface to confirm.

[gauntface]

Great point. Probably makes sense to name the database after the cache (assuming IDB doesn't get upset with the default cache name which includes the sw scope)

[gauntface]

So our mocks for IDB block the user of anything outside of this regex:

// Is the supplied identified a valid identifier?
const r_identifier = /^[a-z_][a-zA-Z0-9_\-\$]*$/;
function validIdentifier(identifier)
{
    if (typeof identifier === 'string' && identifier.match(r_identifier)) return true;
    else return false;
}

I'm not sure if this 100% valid since I tried the idb name:

workbox-precaching-`!@#$%^&*()http://helloworlx.com/

and everything was fine.

Couple of options are:

1. find a way to get around the mock and hope this isn't an issue in browsers
2. Use the cache name but remove any invalid characters

[jeffposnick]

Going with scope.replace(/\W/g, '-') and using that as part of the IDB name seems like a reasonable enough capitulation to the demands of our IDB mock.

[gauntface]

@BenLubar I just published 3.0.0-beta.2 - if you get a chance, could you try it out with your setup and see if it works for you.