Discussion around an API that could collect failures and success

BusinessRuleThoughts.scala

package io.citrine.orion.core.domain

import io.citrine.testing.BaseUnitTest

import scala.collection.mutable.ListBuffer

class BusinessRuleTest extends BaseUnitTest {

  trait StatusInfo {
    def write(msg: String)
    def msgs(): Seq[String]
  }

  class StatusInfoWriter extends StatusInfo {
    private val buffer = ListBuffer[String]()
    override def write(msg: String): Unit = buffer += msg
    override def msgs(): List[String] = buffer.toList
  }

  implicit val statusInfo = new StatusInfoWriter

  case class Row(contents: String)

  def rule(desc: String)(predicate: => Boolean)(implicit statusInfo: StatusInfo): Boolean = {
    val ex = predicate
    val prefix = if (ex) "Passed:" else "Failed:"
    statusInfo.write(s"$prefix $desc")
    ex
  }

  test("allow less than 100 rows") {
    val rows = List(Row("1"))
    rule("Limit rows to 100") {
      rows.length < 100
    } shouldBe true
    statusInfo.msgs contains ("Passed: Limit rows to 100")
  }

  test("fail when rows > 100") {
    val rows = for (i <- 0 to 101) yield Row(s"$i")
    rule("Limit rows to 100") {
      rows.length < 100
    } shouldBe false
    statusInfo.msgs contains ("Failed: Limit rows to 100")
  }

}

Just pondering ideas attempting to separate the traceability use case (recording the fact a test passed vs failed) from writing rules, and ways of integrating it into other validation frameworks like Octopus or Accord, which don't support it.