Consistent unit tests for all the log handlers

[Lewih]

Some log handlers (e.g. httpjson) do not ship a consistent set of unit tests.

This should be addressed on the medium term.

[vkarak]

Hi @Lewih that's something we have about a while ago, but it's not that straightforward to do this as a unit test. You have to spawn an http server and essentially validate the response there. Check the comments in #2760. I'm open to suggestions though and if you have something in mind feel free to open a PR.

[Lewih]

As you said, the debug option can be wisely use to provide an extra layer of testing. The header has to be tested via a listener, but not necessarily an http server. I think a listening socket using the socket built-in will do. HTTP as an application layer is purely text based, so no particular problem should arise.

Anyhow, green-threading will be involved for sure.

Gonna experiment and keep you posted.