Scala example source code file (NonEmptyListTest.scala)

This example Scala source code file (NonEmptyListTest.scala) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Scala by Example" ^TM.

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Java - Scala tags/keywords

foldable1, icons, inil, int, list, nonemptylist, nonemptylisttest, some, speclite

The NonEmptyListTest.scala Scala example source code

package scalaz

import scalaz.scalacheck.ScalazProperties._
import scalaz.scalacheck.ScalazArbitrary._
import std.AllInstances._
import org.scalacheck.Prop.forAll

object NonEmptyListTest extends SpecLite {
  checkAll("NonEmptyList", monad.laws[NonEmptyList])
  checkAll("NonEmptyList", bindRec.laws[NonEmptyList])
  checkAll("NonEmptyList", plus.laws[NonEmptyList])
  checkAll("NonEmptyList", semigroup.laws[NonEmptyList[Int]])
  checkAll("NonEmptyList", equal.laws[NonEmptyList[Int]])
  checkAll("NonEmptyList", order.laws[NonEmptyList[Int]])
  checkAll("NonEmptyList", traverse1.laws[NonEmptyList])
  checkAll("NonEmptyList", FoldableTests.anyAndAllLazy[NonEmptyList])
  checkAll("NonEmptyList", zip.laws[NonEmptyList])
  checkAll("NonEmptyList", align.laws[NonEmptyList])
  checkAll("NonEmptyList", comonad.laws[NonEmptyList])

  "scanLeft1" ! forAll { fa: NonEmptyList[List[Int]] =>
    def f[A]: (List[A], List[A]) => List[A] = _ ::: _
    val a = Foldable1[NonEmptyList].scanLeft1(fa)(f)
    a.list must_=== fa.tail.scanLeft(fa.head)(f)
    a.size must_=== fa.size
  }

  "scanRight1" ! forAll { fa: NonEmptyList[List[Int]] =>
    def f[A]: (List[A], List[A]) => List[A] = _ ::: _
    val a = Foldable1[NonEmptyList].scanRight1(fa)(f)
    a.list must_=== fa.init.scanRight(fa.last)(f)
    a.size must_=== fa.size
  }

  "findLeft/findRight" in {
    val a = NonEmptyList(1, 2, 3, 4, 5)
    Foldable[NonEmptyList].findLeft(a)(_ % 2 == 0) must_=== Some(2)
    Foldable[NonEmptyList].findRight(a)(_ % 2 == 0) must_=== Some(4)
  }

  "findLeft" ! forAll{ a: NonEmptyList[Int] =>
    val f = (_: Int) % 3 == 0
    Foldable[NonEmptyList].findLeft(a)(f) must_=== Foldable[IList].findLeft(a.list)(f)
  }

  "findRight" ! forAll { a: NonEmptyList[Int] =>
    val f = (_: Int) % 3 == 0
    Foldable[NonEmptyList].findRight(a)(f) must_=== Foldable[IList].findRight(a.list)(f)
  }

  "distinct" ! forAll { xs: NonEmptyList[Int] =>
    Option(xs.distinct) must_=== std.list.toNel(Foldable[NonEmptyList].toList(xs).distinct)
  }

  "NonEmptyList size is correct" ! forAll { xs:NonEmptyList[Int] =>
    xs.size must_===(1 + xs.tail.count(b => true))
  }

  "foldl1 is reduceLeft" ! forAll {(rnge: NonEmptyList[IList[Int]]) =>
    val F = Foldable1[NonEmptyList]
    rnge.list.toList.reduceLeft(_++_) must_===(F.foldl1(rnge)(a => b => a ++ b))
  }

  "foldr1 is reduceRight" ! forAll {(rnge: NonEmptyList[IList[Int]]) =>
    val F = Foldable1[NonEmptyList]
    rnge.list.toList.reduceRight(_++_) must_===(F.foldr1(rnge)(a => b => a ++ b))
  }
  "foldRight1 is reduceRight" ! forAll { xs: NonEmptyList[IList[Int]] =>
    val F = Foldable1[NonEmptyList]
    xs.list.toList.reduceRight(_ ++ _) must_== F.foldRight1(xs)(_ ++ _)
  }
  "NonEmptyList.last is correct" ! forAll { xs:NonEmptyList[Int] =>
    xs.reverse.head must_===(xs.last)
  }
  "NonEmptyList.init size is correct" ! forAll { xs:NonEmptyList[Int] =>
    xs.init.count(a => true) must_===(xs.tail.count(a => true))
  }
  "correctness of tails" ! forAll { xs: NonEmptyList[Int] =>
    import NonEmptyList._
    xs.tails must_=== nel(xs, xs.tail match {
      case INil() => INil()
      case ICons(h, t) => nel(h, t).tails.list
    })
  }
  "toNel is self" ! forAll { xs: NonEmptyList[Int] =>
    Foldable1[NonEmptyList].toNel(xs) must_=== xs
  }
  "zipWithIndex" ! forAll { xs: NonEmptyList[Int] =>
    xs.zipWithIndex.list must_== xs.list.zipWithIndex
  }
}