Monads explained in a javascript unit test

Writer Monad and List Monad explained using a javascript unit test. Code is from the article: Best introductions to monad translated from Haskell to Javascript (http://blog.jcoglan.com/2011/03/05/translation-from-haskell-to-javascript-of-selected-portions-of-the-best-introduction-to-monads-ive-ever-read)