Thanks very much for this - I did wonder why this didn't break any of the existing 2.11 tests?

I'll try to take a look over the weekend, sorry for the delay.

I had a quick look at 2.13 but it seems there are some changes needed to support scoverage 1.4.0?

Tests didn’t fail because Scala 2.12 is still used by the plugin (default setup) even though the module source code uses 2.11.
To make plugin to fail you need to override scala for scoverage plugin to be 2.11

Plugins needs a test with scoverage built for 2.11 and Scala 2.11 (and 2.13 would be nice to have to be future-proof)

Now it does not work with 2.13 because scala.collection.JavaCoversions is not there any more
https://www.scala-lang.org/api/current/scala/collection/index.html

Opened #106

Yes - and upgrading to scoverage 1.4.0 requires work too.

I expect this will be easier with an upstream PR to remove the use of Seq when Array would suffice.