deque_spec.rb

$: << File.join(File.expand_path(File.dirname(__FILE__)), '..', 'lib')
require 'algorithms'

describe "(empty deque)", :shared => true do
  it "should return nil when popping objects" do
    @deque.pop_front.should be_nil
    @deque.pop_back.should be_nil
  end

  it "should return a size of 1 when sent #push_front" do
    @deque.push_front(1)
    @deque.size.should eql(1)
  end

  it "should return a size of 1 when sent #push_back" do
    @deque.push_back(1)
    @deque.size.should eql(1)
  end

  it "should return nil when sent #front and #back" do
    @deque.front.should be_nil
    @deque.back.should be_nil
  end

  it "should be empty" do
    @deque.should be_empty
  end

  it "should raise ArgumentError if passed more than one argument" do
    lambda { @deque.class.send("new", Time.now, []) }.should raise_error
  end
end

describe "(non-empty deque)", :shared => true do
  before(:each) do
    @deque.push_back(10)
    @deque.push_back("10")
  end

  it "should return last pushed object with pop_back" do
    @deque.pop_back.should eql("10")
    @deque.pop_back.should eql(10)
  end

  it "should return first pushed object with pop_front" do
    @deque.pop_front.should eql(10)
    @deque.pop_front.should eql("10")
  end

  it "should return a size greater than 0" do
    @deque.size.should eql(2)
  end

  it "should not be empty" do
    @deque.should_not be_empty
  end

  it "should iterate in LIFO order with #each_backward" do
    arr = []
    @deque.each_backward { |obj| arr << obj }
    arr.should eql(["10", 10])
  end

  it "should iterate in FIFO order with #each_forward" do
    arr = []
    @deque.each_forward { |obj| arr << obj }
    arr.should eql([10, "10"])
  end

  it "should return nil after everything's popped" do
    @deque.pop_back
    @deque.pop_back
    @deque.pop_back.should be_nil
    @deque.front.should be_nil
  end
end

describe "empty rubydeque" do
  before(:each) do
    @deque = Containers::RubyDeque.new
  end
  it_should_behave_like "(empty deque)"
end

describe "full rubydeque" do
  before(:each) do
    @deque = Containers::RubyDeque.new
  end
  it_should_behave_like "(non-empty deque)"
end

begin
  Containers::CDeque
  describe "empty cdeque" do
    before(:each) do
      @deque = Containers::CDeque.new
    end
    it_should_behave_like "(empty deque)"
  end

  describe "full cdeque" do
    before(:each) do
      @deque = Containers::CDeque.new
    end
    it_should_behave_like "(non-empty deque)"
  end
rescue Exception
end