gistfile1.rbx

require 'mini/test'

Mini::Test.autorun

class StackOverflow < StandardError; end
class EmptyStackError < StandardError; end

class Stack
  def initialize(max = 1.0/0.0)
    @stack = []
    @max   = max
  end

  def empty?
    @stack.empty?
  end

  def push(object)
    if @stack.size >= @max
      raise StackOverflow
    else
      @stack << object
    end
  end

  def pop
    if @stack.size == 0
      raise EmptyStackError
    else
      @stack.pop
    end
  end
end

class TestStack < Mini::Test::TestCase
  def setup
    @stack = Stack.new
  end

  def test_stack_empty?
    assert @stack.empty?
  end

  def test_stack_not_empty
    @stack.push 1
    refute @stack.empty?
  end

  def test_push_1_then_pop_1
    @stack.push 1
    assert_equal 1, @stack.pop
  end

  def test_faiulere_pop_when_stack_is_empty
    assert_raises EmptyStackError do
      @stack.pop
    end
  end

  def test_failurer_push_when_stack_is_max__0
    @stack = Stack.new(0)
    assert_raises StackOverflow do
      @stack.push 1
    end
  end

  def test_failurer_push_when_stack_is_max__100
    @stack = Stack.new(100)
    100.times {|i| @stack.push i }
    assert_raises StackOverflow do
      @stack.push 1
    end
  end
end