Cannot read property \'join\' of undefined

[akprats33]

There is no check if methods is defined or not in the options.

function configureMethods(options) {
    var methods = options.methods;
    if (methods.join) {
      methods = options.methods.join(','); // .methods is an array, so turn it into a string
    }
    return {
      key: 'Access-Control-Allow-Methods',
      value: methods
    };
  }

[dougwilson]

Hi @akprats33 the value is supposed to get back filled from the defaults (https://github.com/expressjs/cors/blob/master/lib/index.js#L8-L13), so it is weird that it isn't. Can you share what your call to this module look like that produces this?

[akprats33]

const ENABLE_CORS = {origin: true, maxAge: 4 * 86400 };
function handleCORS(req, cb) {
	let origin = req.get('origin');

	// Origin matches whitelist
	if (getWhitelist().indexOf(url.parse(origin).hostname) > -1) {
		return cb(null, ENABLE_CORS);
	}
	return cb(null, DISABLE_CORS);
}

module.exports = cors(handleCORS);

Then it is called as a middleware.

// enable cors
apiRouter.use(cors);

This issue came up when I updated the package. In previous version, default value for methods was used. I think default value is missing now.

[dougwilson]

Thanks, @akprats33 I was able to reproduce. The defaults are not getting mixed in when a function is used, so just need to move around the mixin.

[dougwilson]

Thanks for your patience, everyone. I just pushed a fix for this (and makes the options returned from the delegate act more in line with how it acts when passed in directly) and will publish in an hour or so.