dev.chopsticks.fp.util.ZTraceConcisePrinter.scala Maven / Gradle / Ivy

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package dev.chopsticks.fp.util

import zio.ZTrace
import zio.internal.stacktracer.ZTraceElement

object ZTraceConcisePrinter {
  private def isZioInternal(element: ZTraceElement): Boolean = {
    element match {
      case loc: ZTraceElement.SourceLocation if loc.clazz.startsWith("zio.") => true
      case _ => false
    }
  }

  private def printElement(element: ZTraceElement): String = {
    element match {
      case loc: ZTraceElement.SourceLocation if loc.clazz.startsWith("zio.") => ""
      case loc => loc.prettyPrint
    }
  }

  private def printElements(trace: List[ZTraceElement], prefix: String): List[String] = {
    trace.headOption match {
      case Some(head) =>
        val tail = if (trace.tail.nonEmpty) trace.sliding(2) else Iterator.empty

        (Iterator.single(head :: Nil) ++ tail)
          .foldLeft(List.newBuilder[String]) { (buf, pair) =>
            pair match {
              case prior :: next :: Nil =>
                if (isZioInternal(prior) && isZioInternal(next)) {
                  buf
                }
                else {
                  buf += prefix + printElement(next)
                }
              case next :: Nil =>
                buf += prefix + printElement(next)
              case _ => buf
            }
          }
          .result()

      case None => Nil
    }
  }

  def prettyPrint(trace: ZTrace): String = {
    val executionTrace = trace.executionTrace
    val stackTrace = trace.stackTrace
    val fiberId = trace.fiberId

    val stackPrint = printElements(stackTrace, "  a future continuation at ") match {
      case Nil =>
        s"Fiber:$fiberId was supposed to continue to: " :: Nil
      case lines =>
        s"Fiber:$fiberId was supposed to continue to:" :: lines
    }

    val execPrint = printElements(executionTrace, "  at ") match {
      case Nil =>
        s"Fiber:$fiberId execution trace: " :: Nil
      case lines =>
        s"Fiber:$fiberId execution trace:" :: lines
    }

    val ancestry: List[String] =
      trace
        .parentTrace
        .map(parent => s"Fiber:$fiberId was spawned by:\n" :: ZTraceConcisePrinter.prettyPrint(parent) :: Nil)
        .getOrElse(s"Fiber:$fiberId was spawned by: " :: Nil)

    (stackPrint ++ ("" :: execPrint) ++ ("" :: ancestry)).mkString("\n")
  }
}