Properties of flattenString

sdk/lib/_internal/js_runtime/lib/js_helper.dart

Index: sdk/lib/_internal/js_runtime/lib/js_helper.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/js_helper.dart b/sdk/lib/_internal/js_runtime/lib/js_helper.dart
index 011e45e913cbd06847a69561e55bdb2ebff972aa..4b21b3d90cec6e0060c26b49d70db2c1e8624fcc 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',

[Siggi Cherem (dart-lang), 2016/10/19 21:08:28]

should we have a short-hand nomenclature for none/none/never/true? e.g:
JS('String;pure')?

+              "#.charCodeAt(0) == 0 ? # : #", str, str, str);
   }
 
   static String getTimeZoneName(DateTime receiver) {