Find a multilevel logger framework

[kjetilk]

This module uses mostly console.log and is pretty chatty. We need to use a logger framework with at least info, debug and trace levels.

We should pick something that could be brought to v.next too, and so it should have more levels than that, be maintained and in common use, integrate well with test runs (so that different levels can be chosen directly on the command line), and be easy for people to set loglevels if they need help debugging stuff.

[RubenVerborgh]

Note: NSS currently uses the debug module (used by Express as well).

[kjetilk]

Yeah, but that doesn't appear to have multiple levels, which I feel makes it unusable for this kind of project. Or does it?

[RubenVerborgh]

It does not, and it's a good counterargument.

[Ryuno-Ki]

Check out nodeSolidServer/node-solid-server#920 - I suggested loglevel and winston there. loglevel is quite easy to use, whereas winston is quite sophisticated.

As starter I'd move the logging logic into a dedicated file, so you can exchange the logic there if needed (even if that module is just a proxy to console.log in the beginning).

[kjetilk]

@Ryuno-Ki do you know if loglevel is async?

I'd like to keep quite a lot of logging statements in, as I have found that it helps in projects like ours when people report problems, we can ask them to turn their log level up and try again. But then, it becomes really important that logging isn't occupying more than necessary of resources.

[Ryuno-Ki]

@kjetilk From reading the source code I'd say it is synchronous: https://github.com/pimterry/loglevel/blob/master/lib/loglevel.js