From 1e793c96b2b53fb86d63124f7cac5f842eab9043 Mon Sep 17 00:00:00 2001
From: Stephen Adams <sra@google.com>
Date: Wed, 19 Oct 2016 13:53:46 -0700
Subject: [PATCH] Properties of flattenString

TBR=sigmund@google.com

Review URL: https://codereview.chromium.org/2432993004 .
---
 sdk/lib/_internal/js_runtime/lib/js_helper.dart | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sdk/lib/_internal/js_runtime/lib/js_helper.dart b/sdk/lib/_internal/js_runtime/lib/js_helper.dart
index 011e45e913c..4b21b3d90ce 100644
--- a/sdk/lib/_internal/js_runtime/lib/js_helper.dart
+++ b/sdk/lib/_internal/js_runtime/lib/js_helper.dart
@@ -1036,7 +1036,8 @@ class Primitives {
   }
 
   static String flattenString(String str) {
-    return JS('String', "#.charCodeAt(0) == 0 ? # : #", str, str, str);
+    return JS('returns:String;depends:none;effects:none;throws:never;gvn:true',
+              "#.charCodeAt(0) == 0 ? # : #", str, str, str);
   }
 
   static String getTimeZoneName(DateTime receiver) {