added unit testing, and started implementing unit tests...phew

node_modules/get-caller-file/index.js

@@ -0,0 +1,20 @@
+'use strict';
+
+// Call this function in a another function to find out the file from
+// which that function was called from. (Inspects the v8 stack trace)
+//
+// Inspired by http://stackoverflow.com/questions/13227489
+
+module.exports = function getCallerFile(_position) {
+  var oldPrepareStackTrace = Error.prepareStackTrace;
+  Error.prepareStackTrace = function(err, stack) { return stack; };
+  var stack = new Error().stack;
+  Error.prepareStackTrace = oldPrepareStackTrace;
+
+  var position = _position ? _position : 2;
+
+  // stack[0] holds this file
+  // stack[1] holds where this function was called
+  // stack[2] holds the file we're interested in
+  return stack[position] ? stack[position].getFileName() : undefined;
+};