java - Why when I unit test do I get coverage points with `final lazy val` but not `final val`? -

i have code (project source available here - https://github.com/natemurthy/testing-final-vals):

object main extends app {   final val name = "foo" } 

and i'm using scalatest , sbt coverage plugin test code so:

import org.scalatest.{flatspec,matchers}  class maintest extends flatspec matchers {   should "have name" in {     main.name shouldbe "foo"   } } 

but reason coverage points when include lazy modifier in expression:

why case?

my guess coverage tool counts executed lines.

final val name = "foo"is compiled constant inline value in bytecode private static final in java. when accessing variable read value bytecode constant. more info on inlining constant values during compiling

final lazy val name = "foo"on other hand compiles lazy construction method since there no lazy values in jvm. if access variable lazy construction method executed. more info on scala lazy value bytecode generation