implement options to fetch

[jimmywarting]

• network-only: always download latest from network

• cache-only: always load from cache storage (fail if not cached)

• cache-first: load from cache if it exist, otherwise download, cache & load from network

• network-first: always download latest from network, if it fail: use cache

• fastest: Promise.race solution that loads from both cache and network, when the network completes, then it will also store it to cache

this ideas namely comes from https://googlechromelabs.github.io/sw-toolbox/api.html#handlers

there could also be some solutions that works with cache headers in the response...

[zachsa]

Hi,

I also would like the HTTP modules to be cached on the first Node.js startup (otherwise I spend quite a lot of time waiting for HTTP imports to load).

Please let me know if the pull request is suitable @joeldenning! I did see that there is another open pull request (#5, #6). But I found switching to the make-fetch-happen library seems to make caching easier.

[zachsa]

Here is the loader with caching: https://github.com/zachsa/node-loader-http/blob/fetch-caching/lib/node-loader-http.js. If there is interest in the pull request I can improve this to make the make-fetch-happen library more transparent, which (I think) allows for specifying a proxy agent such as the other pull request introduces.