Composable functions in Javascript with underscore.js contrib

composable.js

// Not composable function: DON'T DO THIS!
function complexProcess() {
  var a = getComponent(globalState),
      b = subprocessOne(a),
      c = subProcessTwo(a, b),
      d = subProcessThree(a, b, c);
  resetGlobalState(d);
}

// Composable Funtion
function complexProcess = _.pipeline(subprocessOne,
                                     subProcessTwo,
                                     subProcessThree); 

var newState = complexProcess(state); // The state is an Object that we build up in the pipeline.
// Side efect is isolated.
resetGlobalState(newState);

// Is like piping in Unix, easy to test, easy to look at each funtion in isolation.