First commit, fixed appending, create, destroy and get, all working fine

tests/test_linkedlist.c

@@ -0,0 +1,32 @@
+#include "linkedlist.h"
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+static void linkedlist_test_append(void **state) {
+    (void) state;
+
+    LinkedList *ll;
+    linkedlist_create(&ll, sizeof(int));
+    for (int i = 10; i < 13; i++) {
+        linkedlist_append(ll, &i);
+    }
+    for (int i = 0; i < 3; i++) {
+        int n;
+        linkedlist_get(ll, i, &n);
+        assert_int_equal(n, i + 10);
+    }
+    linkedlist_destroy(ll);
+}
+
+int main(void) {
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test(linkedlist_test_append),
+    };
+
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}