Add tests for braille commands.

chrome/browser/resources/chromeos/chromevox/testing/assert_additions.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Asserts that a given argument's value is undefined.
  * @param {object} a The argument to check.
  */
 function assertUndefined(a) {
   if (a !== undefined) {
     throw new Error('Assertion failed: expected undefined');
   }
 }
 
 /**
  * Asserts that the argument is neither null nor undefined.
  * @param {object} obj The argument to check.
  * @param {string=} opt_message Error message if the condition is not met.
  */
 function assertNotNullNorUndefined(obj, opt_message) {
   if (obj === undefined || obj === null) {
     throw new Error('Can\'t be null or undefined: ' + (opt_message || '') +
-        '\n' + 'Actual: ' + a);
+        '\n' + 'Actual: ' + obj);
   }
 }
 
 /**
  * Asserts that a given function call throws an exception.
  * @param {string} msg Message to print if exception not thrown.
  * @param {Function} fn The function to call.
  * @param {string} error The name of the exception we expect {@code fn} to
  *     throw.
  */
@@ skipping 41 matching lines @@
 function assertEqualsJSON(expected, actual, opt_message) {
   if (JSON.stringify(actual) !== JSON.stringify(expected)) {
     throw new Error((opt_message ? opt_message + '\n' : '') +
         'Expected ' + JSON.stringify(expected) + '\n' +
         'Got      ' + JSON.stringify(actual));
   }
 }
 
 assertSame = assertEquals;
 assertNotSame = assertNotEquals;