Scala trait for debugging infinity recursions.

README.md

Usage

• Extend your class with Debugable trait
• (optional) write initialCommands in build.sbt
• run sbt REPL on file chage

Extending

See example.scala

initialCommands

For example:

initialCommands in console :=
  """
    |import my.specific.package._
    |MyClass.best(12345)
    |MyClass.best(1.234)
    |MyClass.best(100)
  """.stripMargin

sbt

sbt
~console

debug.scala

trait Debugable {
  private final val DEBUG_MAX_I = 800
  private var debugI = 0

  def d(text: String): Unit = {
    println(text)
    try {
      val stack = Thread.currentThread().getStackTrace()
      val element = stack(3)
      println(s"\t$element")
    } catch {
      case e: Exception => println("Something went wrong")
    }
    debugI += 1
    if (debugI > DEBUG_MAX_I) {
      throw new InfinityRecursion
    }
  }

  class InfinityRecursion() extends RuntimeException("Infinity recursion")

}

example.scala

object MyClass extends Debugable {
  def smaller(number: Double): Double = {
    d("Checking smaller") // for more detailed checking
    if (number > 100) smaller(number / 100) else number
  }

  def larger(number: Double): Double = {
    d() // for fast checking 
    if (number < 100) larger(number * 100) else number
  }

  def best(number: Double): Double = {
    if (number > 100) smaller(number)
    else if (number < 100) larger(number)
    else {
      d("Other case") // Posible source of error
      best(number)
    }
  }
}