Logback backend for kotlin-logging

[neeme-praks-sympower]

Proposal for #449
I'm not sure if this change requires kotlin-logging to always have Logback on runtime classpath or not (how eager is JVM classloading nowadays?) -- but we can figure that detail out later.

[oshai]

Right now it fails on formatting, see how to fix spotless here: https://github.com/oshai/kotlin-logging/blob/master/CONTRIBUTING.md

In addition, since I want it to be both extended (with <class>, <method>, <line>, <file>) maybe we should wrap it with compilerOptions or internalCompilerData data class. I think it will be more obvious that this should not be set.

[neeme-praks-sympower]

Thanks for the feedback! I'll get back to this next week.

[neeme-praks-sympower]

I've now fixed formatting issues and introduced internalCompilerData field.

[oshai]

lgtm, left some comments.

[oshai]

please document that this field is internal and should not be set

[neeme-praks-sympower]

Added JavaDoc

[oshai]

actually here there is no difference in location awerness so this can be removed

[neeme-praks-sympower]

Removed. And renamed methods and fields a bit.

[oshai]

Can you please fix spotless again before I submit it?

[neeme-praks-sympower]

Can you please fix spotless again before I submit it?

Fixed.

I would like to also include a test that would execute JulLoggerWrapperTest without Logback in the classpath -- to make sure that KLoggerFactory can access JulLoggerFactory without needing to load LogbackLoggerFactory (which depends on Logback).

I tried to play around with Gradle build file but my knowledge about Kotlin multiplatform (and Gradle) build system is limited -- maybe you can help out here?

[oshai]

Can you please fix spotless again before I submit it?

Fixed.

I would like to also include a test that would execute JulLoggerWrapperTest without Logback in the classpath -- to make sure that KLoggerFactory can access JulLoggerFactory without needing to load LogbackLoggerFactory (which depends on Logback).

I tried to play around with Gradle build file but my knowledge about Kotlin multiplatform (and Gradle) build system is limited -- maybe you can help out here?

Thanks! I merged the PR and just now see this message. I think it will be difficult to do tests with / without logback in classpath. I also don't think gradle is very good at this. I think we can go without such test.

[neeme-praks-sympower]

I think we can go without such test.

Just to be sure, I ran a manual test with a simple project on my machine -- seems to work just fine (using -Dkotlin-logging-to-jul=true and without Logback in the classpath).

Thanks!