StackSpec.scala

// Copyright © 2010-2016, Esko Luontola <www.orfjackal.net>
// This software is released under the Apache License 2.0.
// The license text is at http://www.apache.org/licenses/LICENSE-2.0

package org.specsy.examples.scala

import org.specsy.scala.ScalaSpecsy
import org.hamcrest.MatcherAssert.assertThat
import org.hamcrest.Matchers._
import org.junit.Assert._

class StackSpec extends ScalaSpecsy {
  val stack = new scala.collection.mutable.Stack[String]

  "An empty stack" >> {

    "is empty" >> {
      assertTrue(stack.isEmpty)
    }
    "After a push, the stack is no longer empty" >> {
      stack.push("a push")
      assertFalse(stack.isEmpty)
    }
  }

  "When objects have been pushed onto a stack" >> {
    stack.push("pushed first")
    stack.push("pushed last")

    "the object pushed last is popped first" >> {
      val poppedFirst = stack.pop()
      assertThat(poppedFirst, is("pushed last"))
    }
    "the object pushed first is popped last" >> {
      stack.pop()
      val poppedLast = stack.pop()
      assertThat(poppedLast, is("pushed first"))
    }
    "After popping all objects, the stack is empty" >> {
      stack.pop()
      stack.pop()
      assertTrue(stack.isEmpty)
    }
  }
}