Scala example source code file (StrictTreeTest.scala)

This example Scala source code file (StrictTreeTest.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

ascii, equal, node, seq, speclite, stricttree, stricttreetest, traverse, tree\'s, vector

The StrictTreeTest.scala Scala example source code

package scalaz

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

object StrictTreeTest extends SpecLite {

  checkAll("StrictTree", order.laws[StrictTree[Int]])
  checkAll("StrictTree", traverse1.laws[StrictTree])
  checkAll("StrictTree", applicative.laws[StrictTree])
  checkAll("StrictTree", comonad.laws[StrictTree])
  checkAll("StrictTree", align.laws[StrictTree])
  checkAll("StrictTree", zip.laws[StrictTree])

  checkAll(FoldableTests.anyAndAllLazy[Tree])

  "indexed" ! forAll { xs: StrictTree[Byte] =>
    val F = Traverse[StrictTree]
    val a = F.indexed(xs)
    Equal[StrictTree[Byte]].equal(a.map(_._2), xs) must_=== true
    F.toList(a) must_=== F.toList(xs).zipWithIndex.map{case (a, b) => (b, a)}
  }

  "A tree must can be rendered as an ASCII string" ! {
    Node(1, Vector(Node(2, Vector(Leaf(3))), Leaf(4))).drawTree must_== Seq(
      "1",
      "|",
      "+- 2",
      "|  |",
      "|  `- 3",
      "|",
      "`- 4").mkString("", "\n", "\n")
  }

  "Equals.equal works" ! forAll { (s: StrictTree[Byte]) =>
    val E = Equal[StrictTree[Byte]]
    E.equal(s, s) must_== true
  }

  "flatMap((Leaf(_)) is identity" ! forAll { (s: StrictTree[Byte]) =>
    val actualTree = s.flatMap(Leaf(_))
    Equal[StrictTree[Byte]].equal(actualTree, s) must_== true
  }

  "flatten is the same as the lazy Tree's flatten" ! forAll { (s: StrictTree[Byte]) =>
    s.flatten must_=== s.toTree.flatten.toVector
  }

  "StrictTree#toTree and Tree#toStrictTree are inverses" ! forAll { (s: StrictTree[Byte]) =>
    Equal[StrictTree[Byte]].equal(s, s.toTree.toStrictTree) must_=== true
  }

  "size gives the same number of elements as flatten" ! forAll { (s: StrictTree[Byte]) =>
    s.flatten.size must_=== s.size
  }

}