Fixed some things in stack.c, first test working

makefile

@@ -35,7 +35,9 @@ $(program_obj_filesobj_files): %.o: %.c
 # --------------------------
 # Unit Tests
 # --------------------------
-unitTests:
+stackTests: stack.o test_stack.c $(unityfolder)/unity.c
+	$(CC) $(CFLAGS) -I$(unityfolder) -o runStackTests test_stack.c stack.o $(unityfolder)/unity.c
+
 	echo "needs to be implemented"
 
 # --------------------------

stack.c

@@ -12,12 +12,16 @@ StackNode *push(StackNode *stack, void *data)
 {
     if(!(stack)) { // check if stack is empty
         stack = malloc(sizeof(StackNode));
+        if(!stack)
+            return NULL;
         stack->stackData = data;
         stack->below = NULL;
         return stack;
     }
 
     StackNode* newStack = malloc(sizeof(StackNode));
+        if(!newStack)
+            return stack;
     newStack->below = stack;
     newStack->stackData = data;
     stack = newStack;
@@ -32,7 +36,6 @@ StackNode *pop(StackNode *stack)
     if(stack) {
         StackNode* temp = stack;
         stack = stack->below;
-        free(temp->data);
         temp->stackData = NULL;
         free(temp);
         temp = NULL;
@@ -55,11 +58,7 @@ void *top(StackNode *stack)
 // Clears stack and releases all memory.
 void clearStack(StackNode *stack)
 {
-    if(stack) {
-        do {
-            stack = pop(stack);
-        } while (stack->below);
-        pop(stack);
-    }
+    while(stack)
+        stack = pop(stack);
 
 }

stack.h

@@ -10,7 +10,7 @@ The latest element is taken from the stack. */
 //TODO: passenden Datentyp als struct anlegen
 
 typedef struct StackNode {
-    StackNode* below;
+    struct StackNode* below;
     void* stackData;
 } StackNode;
 

test_stack.c

@@ -0,0 +1,37 @@
+#include "stack.h"
+#include "unity.h"
+
+
+void test_firstNodeAddedCorrectly(void) {
+    printf("\nStarting first test...\n");
+    StackNode* modelStack = malloc(sizeof(StackNode));
+    int modelData = 5;
+    modelStack->below = NULL;
+    modelStack->stackData = &modelData;
+
+    StackNode* testStack = NULL;
+    int testData = 5;
+    testStack = push(testStack, &testData);
+    TEST_ASSERT_EQUAL_INT(*(int*)modelStack->stackData, *(int*)testStack->stackData);
+    TEST_ASSERT_NULL(testStack->below);
+    clearStack(modelStack);
+    clearStack(testStack);
+}
+
+void setUp(void) {
+
+}
+
+void tearDown(void) {
+
+}
+
+int main(void) {
+
+    UNITY_BEGIN();
+
+    printf("\n----------------------------Stack-Tests----------------------------\n");
+    RUN_TEST(test_firstNodeAddedCorrectly);
+
+    return UNITY_END();
+}