require 'a_more_declarative_rspec'

context "empty" do
  @stack = Stack.new :limit => 10
end

context "one item" => "empty" do
  @stack.push 10
end

context "almost full" => "empty" do
  (2..10).each{ |i| @stack.push i }
end

context "full" => "empty" do
  (1..10).each{ |i| @stack.push i }
end

context_group "not empty" => [ "one item", "almost full", "full" ]
context_group "not full"  => [ "empty", "one item", "almost full" ]

behavior "should accept an item when sent push" => "not full" do
  lambda{ @stack.push Object.new }.should.not.raise
end

behavior "should complain when sent top" => "empty" do
  lambda{ @stack.top }.should.raise StackUnderflowError
end

behavior "should complain when sent pop" => "empty" do
  lambda{ @stack.pop }.should.raise StackUnderflowError
end

behavior "should return top when sent top" => "not empty" do
  @stack.top.should.be 10
end

behavior "should not remove top when sent top" => "not empty" do
  @stack.top.should.be 10
  @stack.top.should.be 10
end

behavior "should return top when sent pop" => "not empty" do
  @stack.pop.should.be 10
end

behavior "should remove top when sent pop" => "not empty" do
  @stack.pop.should.be 10
  contexts "almost full", "full" do
    @stack.top.should.be 9
  end
  contexts "one item" do
    lambda{ @stack.top }.should.raise StackUnderflowError
  end
end

behavior "should remove top when sent pop" => "one item" do
  @stack.pop.should.be 10
end

behavior "should complain on push" => "full" do
  lambda{ @stack.push Object.new }.should.raise StackOverflowError
end