Finished testing insert, had problems with the for loop condition and managing if insert was at the head, all resolved

src/linkedlist.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
+#include <strings.h>
 
 typedef struct Node {
     void *data;
@@ -159,7 +160,7 @@ LinkedListErr linkedlist_insert(LinkedList *ll, size_t index, void *val) {
         return LLIST_NULL;
     }
 
-    if (index >= ll->len) {
+    if (index > ll->len) {
         return LLIST_OUT_OF_BOUNDS;
     }
 
@@ -175,22 +176,25 @@ LinkedListErr linkedlist_insert(LinkedList *ll, size_t index, void *val) {
     }
 
     memcpy(new_node->data, val, ll->elem_size);
-
-    Node *current = ll->head;
-    for (size_t i = 0; i < ll->len; i++) {
-        current = current->next;
-    }
     
     // is head
-    if (current == NULL) {
+    if (index == 0) {
+        new_node->next = ll->head;
         ll->head = new_node;
-        ll->head->next = NULL;
     } else { // also works for the end althoug append should be used for that i guess
+        Node *current = ll->head;
+
+        for (size_t i = 0; i < index; i++) {
+            current = current->next;
+        }
+
         Node *next = current->next;
         current->next = new_node;
         new_node->next = next;
     }
 
+    ll->len = ll->len + 1;
+
     return LLIST_OK;
 }
 

tests/test_linkedlist.c

@@ -91,12 +91,114 @@ static void linkedlist_test_delete_middle(void **state) {
     linkedlist_destroy(ll);
 }
 
+static void linkedlist_test_insert_head(void **state) {
+    (void) state;
+
+    LinkedList *ll;
+    linkedlist_create(&ll, sizeof(int));
+    for (int i = 0; i < 3; i++) {
+        linkedlist_append(ll, &i);
+    }
+
+    int val = 3;
+    linkedlist_insert(ll, 0, &val);
+
+    size_t len;
+    linkedlist_len(ll, &len);
+    assert_int_equal(len, 4);
+
+    int n;
+    linkedlist_get(ll, 0, &n);
+    assert_int_equal(n, 3);
+
+    linkedlist_get(ll, 1, &n);
+    assert_int_equal(n, 0);
+
+    linkedlist_get(ll, 2, &n);
+    assert_int_equal(n, 1);
+
+    linkedlist_get(ll, 3, &n);
+    assert_int_equal(n, 2);
+ 
+    linkedlist_destroy(ll);
+}
+
+static void linkedlist_test_insert_end(void **state) {
+    (void) state;
+
+    LinkedList *ll;
+    linkedlist_create(&ll, sizeof(int));
+    for (int i = 0; i < 3; i++) {
+        linkedlist_append(ll, &i);
+    }
+
+    int val = 3;
+    linkedlist_insert(ll, 2, &val);
+
+    size_t len;
+    linkedlist_len(ll, &len);
+    assert_int_equal(len, 4);
+
+    int n;
+    linkedlist_get(ll, 0, &n);
+    assert_int_equal(n, 0);
+
+    linkedlist_get(ll, 1, &n);
+    assert_int_equal(n, 1);
+
+    linkedlist_get(ll, 2, &n);
+    assert_int_equal(n, 2);
+
+    linkedlist_get(ll, 3, &n);
+    assert_int_equal(n, 3);
+    
+    linkedlist_destroy(ll);
+}
+
+static void linkedlist_test_insert_middle(void **state) {
+    (void) state;
+
+    LinkedList *ll;
+    linkedlist_create(&ll, sizeof(int));
+    for (int i = 0; i < 4; i++) {
+        linkedlist_append(ll, &i);
+    }
+
+    int val = 5;
+    linkedlist_insert(ll, 2, &val);
+
+    size_t len;
+    linkedlist_len(ll, &len);
+    assert_int_equal(len, 5);
+
+    int n;
+    linkedlist_get(ll, 0, &n);
+    assert_int_equal(n, 0);
+
+    linkedlist_get(ll, 1, &n);
+    assert_int_equal(n, 1);
+
+    linkedlist_get(ll, 2, &n);
+    assert_int_equal(n, 2);
+
+    linkedlist_get(ll, 3, &n);
+    assert_int_equal(n, 5);
+
+    linkedlist_get(ll, 4, &n);
+    assert_int_equal(n, 3);
+
+    linkedlist_destroy(ll);
+}
+
 int main(void) {
     const struct CMUnitTest tests[] = {
         cmocka_unit_test(linkedlist_test_append_3_int),
         cmocka_unit_test(linkedlist_test_delete_head),
         cmocka_unit_test(linkedlist_test_delete_end),
         cmocka_unit_test(linkedlist_test_delete_middle),   
+        cmocka_unit_test(linkedlist_test_insert_head),   
+        cmocka_unit_test(linkedlist_test_insert_middle),   
+        cmocka_unit_test(linkedlist_test_insert_end),   
     };
 
     return cmocka_run_group_tests(tests, NULL, NULL);