test: tests for arrayslice to aray done

src/arraylist.c

@@ -579,18 +579,17 @@ ArrayListErr arrayslice_advance(ArraySlice *slice, size_t n) {
 }
 
 ArrayList *arrayslice_to_arraylist(const ArraySlice *slice) {
-    if (slice == NULL) {
+    if (slice == NULL || slice->arr == NULL) {
         return NULL;
     }
 
-    if (slice->current >= slice->end) {
+    if (slice->start >= slice->end) {
         return NULL;
     }
 
-    ArrayList *new_arr = arraylist_init(
-        arraylist_capacity(slice->arr),
-        slice->arr->elem_size);
+    size_t len = slice->end - slice->start;
 
+    ArrayList *new_arr = arraylist_init(arraylist_capacity(slice->arr), slice->arr->elem_size);
     if (new_arr == NULL) {
         return NULL;
     }
@@ -598,8 +597,10 @@ ArrayList *arrayslice_to_arraylist(const ArraySlice *slice) {
     memcpy(
         new_arr->buffer,
         slice->arr->buffer + (slice->start * slice->arr->elem_size),
-        slice->arr->elem_size * (slice->end - slice->current)
+        slice->arr->elem_size * len
     );
 
+    new_arr->len = len;
+
     return new_arr;
 }