Drools rules loop knowledge base / published by https://github.com/dacr/code-examples-manager #6b3ee4ec-6f57-4587-b0ea-1be4118b5a2f/6e053dca54cea9f277fd2dfe8e970e63c2864008

drools-kb-forever-loop-on-modify.sc

// summary : Drools rules loop knowledge base
// keywords : scala, drools, mvel, scalatest, ai, knowledgebase, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 6b3ee4ec-6f57-4587-b0ea-1be4118b5a2f
// created-on : 2019-10-04T09:15:21+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.3.0"
//> using dep "fr.janalyse::drools-scripting:1.1.0"
//> using dep "org.scalatest::scalatest:3.2.16"
// ---------------------

import fr.janalyse.droolscripting._, org.scalatest._, flatspec._, matchers._, OptionValues._
object KbTest extends AnyFlatSpec with should.Matchers {
  val drl =
    """package test
      |
      |declare That
      |  count:int
      |end
      |
      |rule "init" when then insert(new That(0)); end
      |
      |rule "count"
      |when
      |  //$that:That($count:count)
      |  $that:That($count:count , count < 100)
      |then
      |  modify($that) {
      |    setCount($count+1)
      |  }
      |end
      |""".stripMargin

  "test KB" should "work" in {
    val engine = DroolsEngine(drl)
    engine.fireAllRules()
    engine.getModelFirstInstanceAttribute("test.That", "count").value.asInstanceOf[Int] shouldBe 100
  }
}
KbTest.execute()