One more fix

src/main.zig

@@ -291,7 +291,7 @@ fn identifierFromPosition(pos_index: usize, handle: DocumentStore.Handle) []cons
     {}
 
     var end_idx = pos_index;
-    while (end_idx < handle.document.text.len and
+    while (end_idx < handle.document.text.len - 1 and
         (std.ascii.isAlNum(handle.document.text[end_idx]) or handle.document.text[end_idx] == '_')) : (end_idx += 1)
     {}