Added effect math tests

rpg-docs/lib/functions/preventLoop.js

@@ -0,0 +1,27 @@
+preventLoop = function(inputFunction){
+	if(!_.isFunction(inputFunction)) throw new Meteor.Error("Not a function", 
+															"preventLoop can only take a function as an argument");
+	//store a private array of arguments we have been given without returning
+	//if we try to visit the same argument twice before resolving its value
+	//we are in a dependency loop and need to GTFO
+	var visitedArgs = [];
+	return function(argument){
+		var value;
+		//we're still evaluating this attribute, must be in a loop
+		if(_.contains(visitedArgs, argument)) {
+			console.warn("dependency loop detected");
+			return NaN;
+		} else{
+			//push this skill to the list of visited skills
+			//we can't visit it again unless it returns first
+			visitedArgs.push(argument);
+		}
+		try{
+			value = inputFunction.call(this, argument);
+		} finally{
+			//this argument returns or fails, pull it from the array
+			visitedArgs = _.without(visitedArgs, argument);
+		}
+		return value;
+	}
+};