diff --git a/compiler/erg_parser/tests/stream.er b/compiler/erg_parser/tests/stream.er
index 9172a031..bbe520a1 100644
--- a/compiler/erg_parser/tests/stream.er
+++ b/compiler/erg_parser/tests/stream.er
@@ -1,5 +1,6 @@
-print!(1 + 1 |> f())
-print!(1 + 1 |> .abs())
+id x = x
 
-print!(f(1+1))
-print!((1+1).abs())
+1 + 1 |> id() == id(1 + 1) |> assert()
+1 + 2 * 3 |> id() |> id() == id(id(1 + 2 * 3)) |> assert()
+1 + 1 |> .abs() == (1 + 1).abs() |> assert()
+1 + 2 * 3 |> .abs() |> .abs() == (1 + 2 * 3).abs().abs() |> assert()