Fix support for play2.6 versions after play2.6.13

[junder31]

Reopening #94 on a side branch as requested.

Overview

Monitoring on scala/play2.6.18 was not working when I initially installed the newrelic agent. I found that the later versions of play2.6 deprecated the getHandlerFor method on the Server trait and used the Server object similar to how the play2.7 integration works. Since the signatures for the getHandlerFor vary between the trait and object I had to do some refactoring to support both methods.

Testing

I added a new tests for play2.6.18 which uses the object method rather than the trait.

Checks

[ ] Are your contributions backwards compatible with relevant frameworks and APIs? No
[ ] Does your code contain any breaking changes? No
[ ] Does your code introduce any new dependencies? No

[tspring]

Looks like I gave you bad advice about the SkipIfPresent, and both instrumentation modules match for play 2.6.12. I'll poke around and try to find a solution, but wanted to give you a heads up. Thanks again @junder31

[junder31]

@tspring I noticed that. The signatures on the methods differ between 2.6.12 and 2.6.13 though. Won't weaver actually stop it if the actual signature doesn't math when the app starts up? I thought that was the behavior I was seeing when I ran with newrelic in debug mode.

[tspring]

It looks like a type erasure issue and the return type is just Either<A,B> in both 2.12/13. Weaving AsciiSet in the Play-2.13 instrumentation like so, should get around the issue:

import com.newrelic.api.agent.weaver.scala.{ScalaMatchType, ScalaWeave}

// This is weaved to prevent from matching on version 2.12
@ScalaWeave(`type` = ScalaMatchType.Object)
class AsciiSet {
}

[junder31]

@tspring Thanks for the help with finding the right classes to weave/skipIfPresent. It looks like that did the trick locally for me.

[tspring]

👍 Looks good, I'll merge as soon as the tests pass and it should be in the next release (6.2.0). Thanks again for your work on this, it's awesome

[jasonjkeller]

This is awesome. Excellent contribution @junder31 ! 🥇