Summary:
This change switches the sending of log messages to Metro from HTTP over to WebSocket. This is what I should have done from the beginning *however* I only spent very little time on this initially, didn't realize that it would be a popular feature *and* we didn't have a persistent WebSocket connection on the client before that was always on. Together with D16442656 we can finally make this happen!
This change:
* Changes the `fetch` call to `HMRClient.log`
* Removes the middleware and integrates logging with `HmrServer` directly in Metro.
* Simplifies the logging logic as WebSockets guarantee messages are processed in order.
This also fixes an issue makovkastar identified when using the `MessageQueue` spy: because we send messages back and forth over the bridge, using `console.log` within `MessageQueue`'s spy method will actually cause an infinite logging loop. This is the proper solution to that problem instead of hacking around it using custom headers.
Note: in a follow-up we will rename these modules to drop the `HMR` prefix. We have not come up with a better name yet and are open to ideas.
Reviewed By: sebmck
Differential Revision: D16458499
fbshipit-source-id: 4c06acece1fef5234015c877354fb730b155168c
Christoph Nakazawa
81ec2112a1