From 3420045a35ecd3ba1c8ca701a08c94cf08585c60 Mon Sep 17 00:00:00 2001
From: Murilo Pereira <murilo.soares3@gmail.com>
Date: Wed, 16 Feb 2011 22:42:49 -0200
Subject: [PATCH] Refactored 'length(stack)' and added test.

---
 lib/stack.c       | 12 +++++-------
 test/stack_test.c | 24 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/lib/stack.c b/lib/stack.c
index 12d2e63..b033f8d 100644
--- a/lib/stack.c
+++ b/lib/stack.c
@@ -45,15 +45,13 @@ bool empty(struct stack *stack) {
 }
 
 int length(struct stack *stack) {
-  struct stack *iterator = stack;
-  int length = 0;
+  int length;
 
   if (!empty(stack)) {
-    length = 1;
-    while (iterator->next != NULL) {
-      length++;
-      iterator = iterator->next;
-    }
+    for (length = 1; stack->next; stack = stack->next, length++)
+      ;
+  } else {
+    length = 0;
   }
 
   return(length);
diff --git a/test/stack_test.c b/test/stack_test.c
index 4a0bdcc..c4d5f9e 100644
--- a/test/stack_test.c
+++ b/test/stack_test.c
@@ -47,6 +47,28 @@ void test_empty_on_non_empty_stack() {
   return;
 }
 
+void test_length() {
+  struct stack *stack;
+  struct card *card[4];
+
+  allocate_stack(&stack);
+  initialize_stack(stack);
+
+  assert(length(stack) == 0);
+
+  for (int i = 0; i < 4; i++) {
+    allocate_card(&card[i]);
+    initialize_card(card[i]);
+    set_card(card[i], i, SPADES, EXPOSED, 0, 0);
+    push(&stack, card[i]);
+    assert(length(stack) == i + 1);
+  }
+
+  free_stack(stack);
+
+  return;
+}
+
 void test_push_on_empty_stack() {
   struct stack *stack;
   struct card *card;
@@ -199,6 +221,8 @@ void test_stack() {
   test_empty_on_empty_stack();
   test_empty_on_non_empty_stack();
 
+  test_length();
+
   test_push_on_empty_stack();
   test_push_on_non_empty_stack();
   test_push_null_on_empty_stack();