toString method for inherited case class in Scala - scala

Question

I am facing some inconsistency in calling toString method for case-classes in Scala. The first code sample:
case class Person(name: String, age: Int)
val jim = Person("jim", 42)
println(jim)
output: Person(jim,42)
For the next code sample I used a case class that extends Exception:
case class JimOverslept(msg: String) extends Exception
try {
throw JimOverslept(msg = "went to bed late")
} catch {
case e: JimOverslept => println(e)
}
output: playground.CaseClassOutput$JimOverslept
Actually, I would prefer the output like JimOverslept(went to bed late)
What is the reason the both outputs are so different? And what is the best way to obtain the output looks like desired one (JimOverslept(went to bed late))

Answer 1

According to SLS 5.3.2 Case Classes
Every case class implicitly overrides some method definitions of class
scala.AnyRef unless a definition of the same method is already given
in the case class itself or a concrete definition of the same method
is given in some base class of the case class different from AnyRef.
Now toString is already provided by base class in
case class JimOverslept(msg: String) extends Exception
where Exception extends base Throwable which provides toString definition. Hence try providing an override within the case class itself like so
case class JimOverslept(msg: String) extends Exception {
override def toString: String = scala.runtime.ScalaRunTime._toString(this)
}