I am currently following and testing against the WebHDFS REST API documentation for the 1.2.1 release, by Apache. Make sure you enable WebHDFS in the hdfs site configuration file. I use Mocha and should.js for unit testing. They will be required if you want to run the unit tests. To execute the tests, simply npm test, but install the requirements first. You will also likely need to adjust the constants in the test file first (or have a username "ryan" setup for hosts "endpoint1" and "endpoint2").