text: const base64url = require('./base64url');
  
  var testEncodeDecode = function(test, original, encoded) {
    test.assertEqual(base64url.urlSafeEncode(original), encoded);
    test.assertEqual(base64url.urlSafeDecode(encoded), original);
  }
  
  exports.testPlusSubstitution = function(test) {
    testEncodeDecode(test, '~~~', 'fn5-');
  }
  
  exports.testSlashSubstitution = function(test) {
    testEncodeDecode(test, 'ÿÿÿ', '____');
  }
  
  exports.testPadding = function(test) {
    testEncodeDecode(test, 'a', 'YQ');
  }
  
  exports.testURL = function(test) {
    testEncodeDecode(test, 'http://example.com', 'aHR0cDovL2V4YW1wbGUuY29t');
  }
  