Commit fa2bc82

@@ -1,6 +1,6 @@
 class LinkedListStack
   def initialize
-    @head = NullNode.new
+    @head = Node.new(nil)
   end
 
   def push(item)
@@ -10,6 +10,10 @@ class LinkedListStack
   def pop
     @head.pop
   end
+
+  def count
+    0
+  end
 end
 
 class Node
@@ -20,10 +24,7 @@ class Node
   end
 
   def push(item)
-    if @next 
-      @next.push(item)
-    end
-
+    @next.push(item) if @next
     @next = Node.new(item)
   end
 
@@ -43,17 +44,3 @@ class Node
     @next == nil
   end
 end
-
-class NullNode
-  def push(item)
-    if @next
-      @next.push(item)
-    else
-      @next = Node.new(item)
-    end
-  end
-
-  def pop
-    return @next.pop if @next
-  end
-end

@@ -11,21 +11,26 @@ describe LinkedListStack do
     end
   end
 
-  context "when a single item is pushed on to the stack" do
+  context "when a multiple items are pushed on to the stack" do
+    let(:n) { 10 }
+
+    before :each do
+      (1..n).each do |n|
+        sut.push(n)
+      end
+    end
     it "should pop the last item pushed on to the stack" do
-      sut.push(1)
-      sut.push(2)
-      result = sut.pop
-      result.should == 2
+      sut.pop.should == n
     end
 
     it "should pop off each item in reverse order of how they were put on" do
-      (1..10).each do |n|
-        sut.push(n)
-      end
-      (10..1).each do |n|
+      (n..1).each do |n|
         sut.pop.should == n
       end
     end
+
+    it "should have the correct number of items" do
+      sut.count.should == n
+    end
   end
 end