mjsunit: Fix the error message produced by assertInstanceof.

test/mjsunit/mjsunit.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 188 matching lines @@
 
 
   function PrettyPrintArrayElement(value, index, array) {
     if (value === undefined && !(index in array)) return "";
     return PrettyPrint(value);
   }
 
 
   function fail(expectedText, found, name_opt) {
     var message = "Fail" + "ure";
-    if (name_opt) {
-      // Fix this when we ditch the old test runner.
-      message += " (" + name_opt + ")";
+    if (found) {
+      message += ": expected <" + expectedText +
+          "> found <" + PrettyPrint(found) + ">";
+      if (name_opt) {
+        // Fix this when we ditch the old test runner.
+        message += " (" + name_opt + ")";
+      }
+    } else {
+      message += ": " + expectedText;
     }
-
-    message += ": expected <" + expectedText +
-        "> found <" + PrettyPrint(found) + ">";
     throw new MjsUnitAssertionError(message);
   }
 
 
   function deepObjectEquals(a, b) {
     var aProps = Object.keys(a);
     aProps.sort();
     var bProps = Object.keys(b);
     bProps.sort();
     if (!deepEquals(aProps, bProps)) {
@@ skipping 163 matching lines @@
 
   assertInstanceof = function assertInstanceof(obj, type) {
     if (!(obj instanceof type)) {
       var actualTypeName = null;
       var actualConstructor = Object.getPrototypeOf(obj).constructor;
       if (typeof actualConstructor === "function") {
         actualTypeName = actualConstructor.name || String(actualConstructor);
       }
       fail("Object <" + PrettyPrint(obj) + "> is not an instance of <" +
                (type.name || type) + ">" +
-               (actualTypeName ? " but of < " + actualTypeName + ">" : ""));
+               (actualTypeName ? " but of <" + actualTypeName + ">" : ""));
     }
   };
 
 
    assertDoesNotThrow = function assertDoesNotThrow(code, name_opt) {
     try {
       if (typeof code === 'function') {
         code();
       } else {
         eval(code);
@@ skipping 45 matching lines @@
     if (sync_opt === undefined) sync_opt = "";
     assertTrue(OptimizationStatus(fun, sync_opt) !== 1, name_opt);
   }
 
   assertOptimized = function assertOptimized(fun, sync_opt, name_opt) {
     if (sync_opt === undefined) sync_opt = "";
     assertTrue(OptimizationStatus(fun, sync_opt) !== 2, name_opt);
   }
 
 })();