Move PrecacheConfig to external file

[FluorescentHallucinogen]

Generated service-worker.js files are identical except PrecacheConfig variable. What about move PrecacheConfig to external file?

[jeffposnick]

That's intentional. Changing the generated service-worker.js file itself is necessary in order to trigger the service worker update flow, which is what is responsible for caching the updated resources.

As of right now, updates to external files that get pulled in to the main service worker via importScripts() won't trigger the service worker update flow, so it's possible to move the file hashes to an external file. This will change in the future, as the service worker specification has been modified to allow changes to files pulled in via importScripts() to trigger the update flow. However, until all browsers with service worker support are updated to this new behavior, we can't change the current approach.

[FluorescentHallucinogen]

What about leave this issue open until all browsers with service worker support are updated to this new behavior?