Tries.scala のテスト

TriesTest.scala

import org.scalatest._

import scalaz._

import tries._

/**
  * Created by phenan on 2017/10/19.
  */
class TriesTest extends FunSpec with DiagrammedAssertions {
  describe ("Tries.apply") {
    it ("returns a right disjunction when its argument expression does not throw an exception") {
      assert (Tries(10) == \/-(10))
    }
    it ("returns a left disjunction when its argument expression throws an exception") {
      assert (Tries(None.get).isLeft)
    }
  }

  describe ("filters") {
    it ("returns the same value as a receiver when the receiver is a right disjunction and it satisfies the given condition") {
      assert (Succeeds(10).filters(_ % 2 == 0) == Succeeds(10))
    }
    it ("returns a left disjunction when the given condition is not satisfied") {
      assert (Succeeds(10).filters(_ % 3 == 0).isLeft)
    }
    it ("returns the same value as a receiver when the receiver is a left disjunction") {
      assert ((Fails(new Exception("exception")): Tries[Int]).filters(_ => true).isLeft)
    }
  }

  describe ("catches") {
    it ("can catch an exception that are thrown in Tries block") {
      val lambda: PartialFunction[Throwable, Int] = { case _: NoSuchElementException => 0 }
      assert (Tries[Int](None.get).catches(lambda) == 0)
    }
  }
}