harness test: propertyHelper.js (error case)

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

test/harness/verifyProperty-value-error.js

@@ -0,0 +1,39 @@
+// Copyright (C) 2017 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: >
+    Including propertyHelper.js will expose:
+
+        verifyProperty()
+        ...
+
+includes: [propertyHelper.js,sta.js]
+---*/
+
+var threw = false;
+var object = Object.defineProperty({}, "prop", {
+  value: 1
+});
+
+try {
+  verifyProperty(object, "prop", {
+    value: 2
+  });
+} catch(err) {
+  threw = true;
+  if (err.constructor !== Test262Error) {
+    throw new Error(
+      'Expected a Test262Error, but a "' + err.constructor.name +
+      '" was thrown.'
+    );
+  }
+
+  if (err.message !== 'descriptor value should be 2 Expected SameValue(«1», «0») to be true') {
+    $ERROR('The error thrown did not define the specified message.');
+  }
+}
+
+if (threw === false) {
+  $ERROR('Expected a Test262Error, but no error was thrown.');
+}