Monadic-ScalaFX-Demo/src/test/scala/HistoryTest.scala

import org.scalatest.funsuite.AnyFunSuite
import nova.monadic_sfx.util.History
import monix.execution.atomic.Atomic
class HistoryTest extends AnyFunSuite {
  val historyRef = Atomic(History(0))

  test("init") {
    val h = historyRef.get()
    assert(h.state.values == Vector(0))
    assert(h.state.sp == 0)
    assert(h.current == 0)
  }

  test("push 1") {
    val h = historyRef.transformAndGet(_.push(1))
    // logger.debug(mutHistory.ints.toString)
    assert(h.state.values == Vector(0, 1))
    assert(h.state.values.length - 1 == h.state.sp)
    assert(h.current == 1)
  }

  test("push 2") {
    val h = historyRef.transformAndGet(_.push(2))
    // logger.debug(mutHistory.ints.toString)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.values.length - 1 == h.state.sp)
    assert(h.current == 2)
  }

  test("first forward") {
    // logger.debug(mutHistory.ints.toString)
    // logger.debug(mutHistory.sp.toString)
    val h = historyRef.transformAndGet(_.forward)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.sp == 2)
    assert(h.current == 2)
  }

  test("second forward") {
    // logger.debug(mutHistory.ints.toString)
    // logger.debug(mutHistory.sp.toString)
    val h = historyRef.transformAndGet(_.forward)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.sp == 2)
    assert(h.current == 2)
  }
  test("first backward") {
    val h = historyRef.transformAndGet(_.backward)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.sp == 1)
    assert(h.current == 1)
  }
  test("second backward") {
    val h = historyRef.transformAndGet(_.backward)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.sp == 0)
    assert(h.current == 0)
  }
  test("third backward") {
    val h = historyRef.transformAndGet(_.backward)
    assert(h.state.values == Vector(0, 1, 2))
    assert(h.state.sp == 0)
    assert(h.current == 0)
  }
  test("push 3") {
    val h = historyRef.transformAndGet(_.push(3))
    // logger.debug(mutHistory.ints.toString)
    assert(h.state.values == Vector(3))
    assert(h.state.sp == 0)
    assert(h.current == 3)
  }
  test("fourth backward") {
    val h = historyRef.transformAndGet(_.backward)
    assert(h.state.values == Vector(3))
    assert(h.state.sp == 0)
    assert(h.current == 3)
  }
  test("lastly") {
    val h1 = historyRef.transformAndGet(
      _.push(4)
        .push(5)
        .push(6)
        .push(7)
        .push(8)
    )
    assert(h1.state.values == Vector(3, 4, 5, 6, 7, 8))
    assert(h1.state.sp == 5)
    assert(h1.current == 8)
    val h2 = historyRef.transformAndGet(_.backward.backward)
    assert(h2.current == 6)
    assert(h2.state.sp == 3)
    val h3 = historyRef.transformAndGet(_.push(9))
    assert(h3.state.values == Vector(3, 4, 5, 9))
    assert(h3.state.sp == 3)
    assert(h3.current == 9)
    for (i <- 1 to 4) historyRef.transform(_.backward)
    // assert(h.current == None)
    // assert(h.ints == Vector.empty)
    val h4 = historyRef.get()
    assert(h4.state.sp == 0)
    assert(h4.current == 3)
    val h5 = historyRef.transformAndGet(_.push(1))
    assert(h5.current == 1)
    assert(h5.state.sp == 0)

  }
}