diff --git a/I2_Dobble/bintreeTest.c b/I2_Dobble/bintreeTest.c
index 6642f9f..588060b 100644
--- a/I2_Dobble/bintreeTest.c
+++ b/I2_Dobble/bintreeTest.c
@@ -1,13 +1,119 @@
-#include "bintree.h"
 #include "unity.h"
-#include "unity_internals.h"
+#include "bintree.h"
+#include <stdlib.h>
+
+static int compare(const void *a, const void *b)
+{
+    return (*(int *)a > *(int *)b) - (*(int *)a < *(int *)b);
+}
 
 void setUp(void) { }
 void tearDown(void) { }
 
-int main()
+void test_addToTree_single_element(void)
+{
+    TreeNode *root = NULL;
+    int value = 10;
+    int dup = -1;
+
+    root = addToTree(root, &value, sizeof(int), compare, &dup);
+
+    TEST_ASSERT_NOT_NULL(root);
+    TEST_ASSERT_EQUAL_INT(10, *(int*)root->data);
+    TEST_ASSERT_EQUAL_INT(0, dup);    // neuer Eintrag
+
+    clearTree(root);
+}
+
+void test_addToTree_multiple_elements_and_size(void)
+{
+    TreeNode *root = NULL;
+    int values[] = {5, 3, 7, 1, 4};
+    int dup = -1;
+
+    for (int i = 0; i < 5; i++)
+        root = addToTree(root, &values[i], sizeof(int), compare, &dup);
+
+    TEST_ASSERT_EQUAL_UINT(5, treeSize(root));
+
+    clearTree(root);
+}
+
+void test_addToTree_duplicate_detection(void)
+{
+    TreeNode *root = NULL;
+    int val = 42;
+    int dup;
+
+    root = addToTree(root, &val, sizeof(int), compare, &dup);
+    TEST_ASSERT_EQUAL(0, dup);
+
+    addToTree(root, &val, sizeof(int), compare, &dup);
+    TEST_ASSERT_EQUAL(1, dup);
+
+    clearTree(root);
+}
+
+void test_treeSize_empty_tree_detection(void)
+{
+    TEST_ASSERT_EQUAL_UINT(0, treeSize(NULL));
+}
+
+void test_nextTreeData_returns_inorder(void)
+{
+    TreeNode *root = NULL;
+    int values[] = {5, 3, 7, 2, 4, 6, 8};
+
+    // Einfügen
+    for (int i = 0; i < 7; i++)
+        root = addToTree(root, &values[i], sizeof(int), compare, NULL);
+
+    /* Erwartete Reihenfolge (inorder): 2,3,4,5,6,7,8 */
+    int expected[] = {2,3,4,5,6,7,8};
+
+    int idx = 0;
+    void *p = nextTreeData(root);   // Iterator starten
+
+    while (p != NULL)
+    {
+        TEST_ASSERT_EQUAL_INT(expected[idx], *(int*)p);
+        idx++;
+        p = nextTreeData(NULL);     // Fortsetzen mit NULL
+    }
+
+    TEST_ASSERT_EQUAL(7, idx); //alle Einträge geprüft
+
+    clearTree(root);
+}
+
+void test_treeSize_returns_correct_size()
+{
+    TreeNode *root = NULL;
+    int values[] = {8, 3, 10, 1, 6, 14};
+
+    // ersten Baum aufbauen
+    for (int i = 0; i < 6; i++)
+        root = addToTree(root, &values[i], sizeof(int), compare, NULL);
+
+    TEST_ASSERT_EQUAL_UINT(6, treeSize(root));
+
+    // Baum löschen
+    clearTree(root);
+    root = NULL;
+
+    TEST_ASSERT_EQUAL_UINT(0, treeSize(root));
+}
+
+int main(void)
 {
     UNITY_BEGIN();
 
+    RUN_TEST(test_addToTree_single_element);
+    RUN_TEST(test_addToTree_multiple_elements_and_size);
+    RUN_TEST(test_addToTree_duplicate_detection);
+    RUN_TEST(test_treeSize_empty_tree_detection);
+    RUN_TEST(test_nextTreeData_returns_inorder);
+    RUN_TEST(test_treeSize_returns_correct_size);
+
     return UNITY_END();
-}
\ No newline at end of file
+}