NetworkFirst POST caching for gRPC-Web compatibility

[asavageiv]

Hi,
I'm trying to add PWA support to Memos which uses gRPC-Web for its API requests. gRPC-Web specifies that all requests must be POST requests, whether they are mutation requests or not. It would be nice to use workbox.NetworkFirst with such requests.

[asavageiv]

I see that this is not easily possible because Cache does not support caching POST requests. I'm not sure if I should move away from gRPC-Web if I want a PWA, implement some kind of custom handler that mangles the POST responses into GET responses, or something else.