Added linkedlist_delete, funtions by index, one test was added and passed for checking when eliminate head, subsequent commits will add more tests for this function

include/linkedlist.h

@@ -22,5 +22,6 @@ LinkedListErr linkedlist_delete(LinkedList *ll, size_t index);
 LinkedListErr linkedlist_pop(LinkedList *ll, size_t index, void *out);
 LinkedListErr linkedlist_insert(LinkedList *ll, size_t index, void *out);
 LinkedListErr linkedlist_get(const LinkedList *ll, size_t index, void *out);
+LinkedListErr linkedlist_len(const LinkedList *ll, size_t *out);
 
 #endif /* ifndef LINKEDLIST_H */

src/linkedlist.c

@@ -120,3 +120,45 @@ LinkedListErr linkedlist_get(const LinkedList *ll, size_t index, void *out) {
 
     return LLIST_OK;
 }
+
+LinkedListErr linkedlist_delete(LinkedList *ll, size_t index) {
+    if (ll == NULL) {
+        return LLIST_NULL;
+    }
+
+    if (index >= ll->len) {
+        return LLIST_OUT_OF_BOUNDS;
+    }
+
+    Node *before = NULL;
+    Node *current = ll->head;
+    for (size_t i = 0; i < index; i++) {
+        before = current;
+        current = current->next;
+    }
+
+    // Take the node OUT of the list, if before is NULL that means
+    // is the head we are talking about so the change is different
+    if (before == NULL) {
+        ll->head = current->next;
+    } else {
+        // If its last current-next is just NULL so is okay
+        before->next = current->next;
+    }
+
+    // Fuck them dangling pointers
+    free(current->data);
+    free(current);
+    ll->len = ll->len - 1;
+
+    return LLIST_OK;
+}
+
+LinkedListErr linkedlist_len(const LinkedList *ll, size_t *out) {
+    if (ll == NULL) {
+        return LLIST_NULL;
+    }
+
+    *out = ll->len;
+    return LLIST_OK;
+}

tests/test_linkedlist.c

@@ -7,7 +7,7 @@
 #include <setjmp.h>
 #include <cmocka.h>
 
-static void linkedlist_test_append(void **state) {
+static void linkedlist_test_append_3_int(void **state) {
     (void) state;
 
     LinkedList *ll;
@@ -23,9 +23,30 @@ static void linkedlist_test_append(void **state) {
     linkedlist_destroy(ll);
 }
 
+static void linkedlist_test_delete_head(void **state) {
+    (void) state;
+
+    LinkedList *ll;
+    linkedlist_create(&ll, sizeof(int));
+    for (int i = 0; i < 3; i++) {
+        linkedlist_append(ll, &i);
+    }
+    linkedlist_delete(ll, 0);
+    size_t len;
+    linkedlist_len(ll,&len);
+    assert_int_equal(len, 2);
+    for (int i = 0; i < 2; i++) {
+        int n;
+        linkedlist_get(ll, i, &n);
+        assert_int_equal(n, i + 1);
+    }
+    linkedlist_destroy(ll);
+}
+
 int main(void) {
     const struct CMUnitTest tests[] = {
-        cmocka_unit_test(linkedlist_test_append),
+        cmocka_unit_test(linkedlist_test_append_3_int),
+        cmocka_unit_test(linkedlist_test_delete_head),
     };
 
     return cmocka_run_group_tests(tests, NULL, NULL);