Don't crash if the root of a trace is a TypeParameter

[eygraber]

Fixes #426

I'm not sure if this is the best solution, or why the type parameter is included in the CycleDetector. An alternate option is to catch this in the CycleDetector and just filter it out. Another option is to catch any exceptions from toTypeName() and use typeRef.toString() instead.

[eygraber]

@evant this is making debugging pretty difficult in one of my projects. Any chance it can get merged in soon?

[evant]

This won't completely fix this as a type param can be arbitrarily nested, for example changing your test from

val c: C

to

val c: () -> C

will cause the same exception.

[evant]

maybe we could wrap toTypeName() in a try/catch and fallback to typeRef.toString() for now?

As an aside, I really wish ksp's toString() properly showed type params, so we wouldn't need to rely on kotlinpoet at all. I submitted a pr to fix this but it's been ignored 😐 google/ksp#1737

[eygraber]

I updated the test to reflect that and changed to try catch.

[evant]

detekt errors, ./gradlew detekt --auto-correct should fix

[eygraber]

Done