Test fails with run_once is not defined

[dpovey]

I have a test that has 4 different cases. The 4th (and periodically the 3rd) fails with the following error:

Uncaught ReferenceError: run_once is not defined
      at Request._callback (node_modules/auth0-rules-testharness/index.js:69:20)
      at Request.self.callback (node_modules/request/request.js:188:22)
      at Request.<anonymous> (node_modules/request/request.js:1171:10)
      at IncomingMessage.<anonymous> (node_modules/request/request.js:1091:12)
      at endReadableNT (_stream_readable.js:974:12)
      at _combinedTickCallback (internal/process/next_tick.js:74:11)
      at process._tickCallback (internal/process/next_tick.js:98:9)

This looks like the webtask request is failing with a 429. In this scenario its supposed to set a timer and retry. However the callback "run_once" is not defined.

I fixed this locally, by something like:

if (res.statusCode === 429) {
  var backoff = (+res.headers['retry-after'] || 5) * 1000;
  backoff += Math.floor(Math.random() * backoff);
  winston.debug('scheduling retry of auth0-sandbox request', {
      backoff: backoff
  });
  var run_once = function() {
    request(options, function (err, res, body) {
      if (err) {
        if (typeof err === 'object' && (err.code === 'ETIMEDOUT' || err.code === 'ESOCKETTIMEDOUT')) {
          return callback(new Error(params.timeout));
        }
        return callback(err);
      }
      process_result(res, body)
    })
  }
  setTimeout(run_once, backoff);
  return;
}

process_result(res, body)

function process_result(res, body) {
    // Previous process flow from here...
    if (res.statusCode !== 200 && res.statusCode !== 500) {

    var errorMessage = 'Invalid response code from the auth0-sandbox: HTTP ' + res.statusCode + '.';
    var parsedBody = toJSON(body);
    ...