An updated (self documented) methods.js, borrowed from rails: https://github.com/rails/rails/blob/401ee98dacc5bac23d8b934765cc64a56bfb5661/actionpack/lib/action_dispatch/http/request.rb#L49

methods.js

/*!
 * Express - router - methods
 * Copyright(c) 2010 TJ Holowaychuk <tj@vision-media.ca>
 * MIT Licensed
 */

/**
* Hypertext Transfer Protocol -- HTTP/1.1 
* http://www.ietf.org/rfc/rfc2616.txt
*/
var RFC2616 = "OPTIONS GET HEAD POST PUT DELETE TRACE CONNECT"

/**
* HTTP Extensions for Distributed Authoring -- WEBDAV
* http://www.ietf.org/rfc/rfc2518.txt
*/
var RFC2518 = "PROPFIND PROPPATCH MKCOL COPY MOVE LOCK UNLOCK"

/**
* Versioning Extensions to WebDAV 
* http://www.ietf.org/rfc/rfc3253.txt
*/
var RFC3253 = "VERSION-CONTROL REPORT CHECKOUT CHECKIN UNCHECKOUT MKWORKSPACE UPDATE LABEL MERGE BASELINE-CONTROL MKACTIVITY"

/**
* Ordered Collections Protocol (WebDAV) 
* http://www.ietf.org/rfc/rfc3648.txt
*/
var RFC3648 = "ORDERPATCH"

/**
* Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol 
* http://www.ietf.org/rfc/rfc3744.txt
*/
var RFC3744 = "ACL"

/**
* Web Distributed Authoring and Versioning (WebDAV) SEARCH
* http://www.ietf.org/rfc/rfc5323.txt
*/
var RFC5323 = "SEARCH"

/**
* PATCH Method for HTTP 
* http://www.ietf.org/rfc/rfc5789.txt
*/
var RFC5789 = "PATCH"

module.exports = [].concat(RFC2616, RFC2518, RFC3253, RFC3648, RFC3744, RFC5323, RFC5789).map(function(rfc){return rfc.toLowerCase().split(" ")})