Jenkins script quitting prematurely when using npm install on Windows

i would recommend not using the local grunt / nodejs install, but instead getting jenkins to do this for you!

it's much easier and means there's less coupling to system specific installs and variables.

steps:

a) use nodejs jenkins plugin + get it to install nodejs on machine/grunt-cli -> Jenkins integration with Grunt

b) populate your package.json with any nodejs dependances required, eg grunt/grunt-zip etc

c) when running grunt just do a "npm update" before "grunt" command

that way your not doing explicit npm install, it's all configured from your package.json, and your build scripts will be less brittle, and your developers can use the same steps as the build server, eg "npm update;grunt" locally same as build server

So it turns out that npm is a batch file, not an executable, so it needs to be invoked using call from the Jenkins script:

call npm install grunt