#!/usr/bin/env ruby

# test_binarytree.rb
#
# $Revision: 1.5 $ by $Author: anupamsg $
# $Name:  $
#
# Copyright (c) 2006, 2007 Anupam Sengupta
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# - Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
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# - Redistributions in binary form must reproduce the above copyright notice, this
#   list of conditions and the following disclaimer in the documentation and/or
#   other materials provided with the distribution.
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# - Neither the name of the organization nor the names of its contributors may
#   be used to endorse or promote products derived from this software without
#   specific prior written permission.
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#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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require 'test/unit'
require 'tree/binarytree'

module TestTree
  # Test class for the Tree node.
  class TestBinaryTreeNode < Test::Unit::TestCase

    def setup
      @root = Tree::BinaryTreeNode.new("ROOT", "Root Node")

      @left_child1  = Tree::BinaryTreeNode.new("A Child at Left", "Child Node @ left")
      @right_child1 = Tree::BinaryTreeNode.new("B Child at Right", "Child Node @ right")

    end

    def teardown
      @root.remove!(@left_child1)
      @root.remove!(@right_child1)
      @root = nil
    end

    def test_initialize
      assert_not_nil(@root, "Binary tree's Root should have been created")
    end

    def test_add
      @root.add  @left_child1
      assert_same(@left_child1, @root.leftChild, "The left node should be left_child1")
      assert_same(@left_child1, @root.firstChild, "The first node should be left_child1")

      @root.add @right_child1
      assert_same(@right_child1, @root.rightChild, "The right node should be right_child1")
      assert_same(@right_child1, @root.lastChild, "The first node should be right_child1")

      assert_raise RuntimeError do
        @root.add Tree::BinaryTreeNode.new("The third child!")
      end

      assert_raise RuntimeError do
        @root << Tree::BinaryTreeNode.new("The third child!")
      end
    end

    def test_leftChild
      @root << @left_child1
      @root << @right_child1
      assert_same(@left_child1, @root.leftChild, "The left child should be 'left_child1")
      assert_not_same(@right_child1, @root.leftChild, "The right_child1 is not the left child")
    end

    def test_rightChild
      @root << @left_child1
      @root << @right_child1
      assert_same(@right_child1, @root.rightChild, "The right child should be 'right_child1")
      assert_not_same(@left_child1, @root.rightChild, "The left_child1 is not the left child")
    end

    def test_leftChild_equals
      @root << @left_child1
      @root << @right_child1
      assert_same(@left_child1, @root.leftChild, "The left child should be 'left_child1")

      @root.leftChild = Tree::BinaryTreeNode.new("New Left Child")
      assert_equal("New Left Child", @root.leftChild.name, "The left child should now be the new child")
      assert_equal("B Child at Right", @root.lastChild.name, "The last child should now be the right child")

      # Now set the left child as nil, and retest
      @root.leftChild = nil
      assert_nil(@root.leftChild, "The left child should now be nil")
      assert_nil(@root.firstChild, "The first child is now nil")
      assert_equal("B Child at Right", @root.lastChild.name, "The last child should now be the right child")
    end

    def test_rightChild_equals
      @root << @left_child1
      @root << @right_child1
      assert_same(@right_child1, @root.rightChild, "The right child should be 'right_child1")

      @root.rightChild = Tree::BinaryTreeNode.new("New Right Child")
      assert_equal("New Right Child", @root.rightChild.name, "The right child should now be the new child")
      assert_equal("A Child at Left", @root.firstChild.name, "The first child should now be the left child")
      assert_equal("New Right Child", @root.lastChild.name, "The last child should now be the right child")

      # Now set the right child as nil, and retest
      @root.rightChild = nil
      assert_nil(@root.rightChild, "The right child should now be nil")
      assert_equal("A Child at Left", @root.firstChild.name, "The first child should now be the left child")
      assert_nil(@root.lastChild, "The first child is now nil")
    end

    def test_isLeftChild_eh
      @root << @left_child1
      @root << @right_child1

      assert(@left_child1.isLeftChild?, "left_child1 should be the left child")
      assert(!@right_child1.isLeftChild?, "left_child1 should be the left child")

      # Now set the right child as nil, and retest
      @root.rightChild = nil
      assert(@left_child1.isLeftChild?, "left_child1 should be the left child")

      assert(!@root.isLeftChild?, "Root is neither left child nor right")
    end

    def test_isRightChild_eh
      @root << @left_child1
      @root << @right_child1

      assert(@right_child1.isRightChild?, "right_child1 should be the right child")
      assert(!@left_child1.isRightChild?, "right_child1 should be the right child")

      # Now set the left child as nil, and retest
      @root.leftChild = nil
      assert(@right_child1.isRightChild?, "right_child1 should be the right child")
      assert(!@root.isRightChild?, "Root is neither left child nor right")
    end

    def test_swap_children
      @root << @left_child1
      @root << @right_child1

      assert(@right_child1.isRightChild?, "right_child1 should be the right child")
      assert(!@left_child1.isRightChild?, "right_child1 should be the right child")

      @root.swap_children

      assert(@right_child1.isLeftChild?, "right_child1 should now be the left child")
      assert(@left_child1.isRightChild?, "left_child1 should now be the right child")
      assert_equal(@right_child1, @root.firstChild, "right_child1 should now be the first child")
      assert_equal(@left_child1, @root.lastChild, "left_child1 should now be the last child")
      assert_equal(@right_child1, @root[0], "right_child1 should now be the first child")
      assert_equal(@left_child1, @root[1], "left_child1 should now be the last child")
    end
  end
end

# $Log: test_binarytree.rb,v $
# Revision 1.5  2007/12/22 00:28:59  anupamsg
# Added more test cases, and enabled ZenTest compatibility.
#
# Revision 1.4  2007/12/18 23:11:29  anupamsg
# Minor documentation changes in the binarytree class.
#
# Revision 1.3  2007/10/02 03:07:30  anupamsg
# * Rakefile: Added an optional task for rcov code coverage.
#
# * test/test_binarytree.rb: Removed the unnecessary dependency on "Person" class.
#
# * test/test_tree.rb: Removed dependency on the redundant "Person" class.
#
# Revision 1.2  2007/08/30 22:06:13  anupamsg
# Added a new swap_children method for the Binary Tree class.
# Also made minor documentation updates and test additions.
#
# Revision 1.1  2007/07/21 04:52:37  anupamsg
# Renamed the test files.
#
# Revision 1.4  2007/07/19 02:03:57  anupamsg
# Minor syntax correction.
#
# Revision 1.3  2007/07/19 02:02:12  anupamsg
# Removed useless files (including rdoc, which should be generated for each release.
#
# Revision 1.2  2007/07/18 20:15:06  anupamsg
# Added two predicate methods in BinaryTreeNode to determine whether a node
# is a left or a right node.
#