Support for HTTP 304 status to work with Rails weak etags

[BilalBudhani]

react-refetch treats 304 response from Rails 5 as 200 and considers body as json. Whereas, 304 doesn't return any body and so the whole thing breaks. Can we return previously returned 200 response in case of 304 status?

[ryanbrainard]

According to JakeChampion/fetch#241, Chrome and Firefox should theortically convert the 304 into a 200. What browser and fetch implementation are you using? We should probably also expose the cache option for fetch.

[BilalBudhani]

@ryanbrainard Oh, I see. I'm using this library in React Native that's the reason I'm facing this problem.

[ryanbrainard]

I see, it would be best to fix it by using a fetch impl that does the right thing, but if it's a simple fix in react-refetch to handle the status correctly, I'd be open to a pull request. However, I think the tricky part is going to be retrieving the cached body -- does your fetch handle that?

[objectiveSee]

@ryanbrainard did you ever configure the network request to correctly retrieve the cached body? Thanks!

[ryanbrainard]

@objectiveSee No, sorry, I haven't.

[objectiveSee]

It's unclear whether you need to set the outgoing request's etag headers manually or not

[ryanbrainard]

Since this is handled correctly in browsers, I think the easiest solution here is going to be to wrap fetch with a caching layer to handle this in other environments (e.g. React Native). Similar to this (but handle the headers and such):

https://github.com/heroku/react-refetch#on-changing-the-fetch-and-request-implementations

I'm going to close this issue since there's not a change needed in this lib; however, if someone would like to update the readme with instructions or an example, I'd be happy to accept a PR.