docs: add info about service-worker and HTTP caching headers into Firebase section

[bobrosoft]

Tricky issue, if you not aware on how service-workers work. Related to #2440

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[gaearon]

Seriously, Firebase is still not doing this by default?

cc @addyosmani @jeffposnick Is this expected?

[bobrosoft]

Seriously, Firebase is still not doing this by default?

@gaearon no, unfort :( And that thing is crucial when deploying to Firebase, because service-worker enabled in create-react-app by default.

[gaearon]

This sounds a bit silly given that Firebase is a Google project and Google's the one pushing for service worker adoption.

[gaearon]

(To clarify, I refer to the situation as silly, not your post)

[jeffposnick]

This sounds a bit silly given that Firebase is a Google project and Google's the one pushing for service worker adoption.

I'll agree that it's silly/frustrating, but for different reasons: this configuration shouldn't be necessary anymore, as per the service worker specification, and is no longer necessary in Firefox, which has been updated to ignore HTTP caches for service workers by default.

Unfortunately, and as discussed elsewhere, Chrome hasn't yet made that change, though there is at least a changelist under review.

Adding this recommendation to the docs for the time being to account for the current behavior of Chrome couldn't hurt.

(I wouldn't expect Firebase to make changes to their hosting environment to accommodate Chrome's inconsistent-with-the-spec behavior at this point.)

[gaearon]

Fair, thank you for explaining! I’m sorry I snapped a little.