1 files changed, 21 insertions, 0 deletions
diff --git a/test/built-ins/String/prototype/toUpperCase/S15.5.4.18_A1_T10.js b/test/built-ins/String/prototype/toUpperCase/S15.5.4.18_A1_T10.js
new file mode 100644
index 000000000..0da16d896
--- /dev/null
+++ b/test/built-ins/String/prototype/toUpperCase/S15.5.4.18_A1_T10.js
@@ -0,0 +1,21 @@
+// Copyright 2009 the Sputnik authors.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+info: String.prototype.toUpperCase()
+es5id: 15.5.4.18_A1_T10
+description: >
+    Call toUpperCase() function of object with overrode toString
+    function
+---*/
+
+var __obj = {toString:function(){return "\u0041b";}}
+__obj.toUpperCase = String.prototype.toUpperCase;
+
+//////////////////////////////////////////////////////////////////////////////
+//CHECK#1
+if (__obj.toUpperCase() !=="AB") {
+  $ERROR('#1: var __obj = {toString:function(){return "\u0041b";}}; __obj.toUpperCase = String.prototype.toUpperCase; __obj.toUpperCase() ==="AB". Actual: '+__obj.toUpperCase() );
+}
+//
+//////////////////////////////////////////////////////////////////////////////