diff --git a/crates/loro-internal/src/container/text/rope.rs b/crates/loro-internal/src/container/text/rope.rs
index c770c6b9..fbb50083 100644
--- a/crates/loro-internal/src/container/text/rope.rs
+++ b/crates/loro-internal/src/container/text/rope.rs
@@ -74,8 +74,9 @@ impl Rope {
             loop {
                 match node {
                     Node::Internal(internal_node) => {
-                        if index == 0{
-                            return 0
+                        if index == 0 {
+                            assert_eq!(ans, 0);
+                            return 0;
                         }
                         let result = find_pos_internal(internal_node, index, &src_cache);
                         if !result.found {
diff --git a/crates/loro-internal/tests/test.rs b/crates/loro-internal/tests/test.rs
index 82f24cac..5adaab1a 100644
--- a/crates/loro-internal/tests/test.rs
+++ b/crates/loro-internal/tests/test.rs
@@ -31,10 +31,11 @@ fn example_text() {
     text.insert_utf16(&doc, 0, "你好").unwrap();
     text.insert_utf16(&doc, 1, "我").unwrap();
     text.insert_utf16(&doc, 1, "abc").unwrap();
-    text.insert_utf16(&doc, 2, "dd").unwrap();
-    println!("text {:?}", text.get_value());
+    assert_eq!(text.get_value().as_string().unwrap().as_ref(), "你abc我好");
     text.delete_utf16(&doc, 1, 1).unwrap();
-    println!("text {:?}", text.get_value());
+    assert_eq!(text.get_value().as_string().unwrap().as_ref(), "你bc我好");
+    text.delete_utf16(&doc, 0, 1).unwrap();
+    assert_eq!(text.get_value().as_string().unwrap().as_ref(), "bc我好");
 }
 
 #[test]