Tone.js/test/helper/APITest.js

define(["helper/Test", "Tone/type/Type", "Tone/core/Transport", "Tone/type/Time", 
	"Tone/type/Frequency"], function(Test, Type, Transport, Time, Frequency){

	//modified from http://stackoverflow.com/questions/15298912/javascript-generating-combinations-from-n-arrays-with-m-elements
	function generatePermutations(args){
		var results = [], max = args.length-1;
		function helper(arr, i){
			for (var j = 0; j < args[i].length; j++){
				var a = arr.slice(0); // clone arr
				a.push(args[i][j]);
				if (i===max){
					results.push(a); 
				} else {
					helper(a, i+1); 
				}
			}
		}
		helper([], 0);
		return results;
	}

	function getVariations(param){
		if (typeof param === "string" && param.indexOf("=") !== -1){
			return [undefined].concat(getVariations(param.replace("=", "")));
		} else if (param === "Time"){
			return ["2n", Time("4n"), { "4n" : 1 }];
		} else if (param === "Number"){
			return [20, -0.5];
		} else if (param === "NormalRange"){
			return [0, 0.5];
		} else if (param === "Frequency"){
			return ["C#4", Frequency("A4")];
		} else if (param === "Function"){
			return [function(){}];
		} else {
			return param;
		}
	}

	function generateArgs(args){
		// turn the object into an array
		var keys = [];
		if (!Array.isArray(args)){
			keys = Object.keys(args);
			var tmp = [];
			for (var p in args){
				tmp.push(args[p]);
			}
			args = tmp;
		}
		for (var i = 0; i < args.length; i++){
			args[i] = getVariations(args[i]);
		}
		//generate all the permutations
		if (keys.length){
			var permutations = generatePermutations(args);
			permutations.map(function(permutation, index){
				var obj = {};
				permutation.map(function(val, index){
					obj[keys[index]] = val;
				});
				permutations[index] = [obj];
			});
			return permutations;
		} else {
			return generatePermutations(args);
		}
	}

	function silenceWarning(cb){
		var warning = console.warn;
		console.warn = function(){};
		cb();
		console.warn = warning;
	}

	return {
		method : function(constructor, fn, args, consArgs){

			it(fn+" ("+args.join(", ") + ")", function(){
				silenceWarning(function(){
					var permutations = generateArgs(args);
					for (var i = 0; i < permutations.length; i++){
						var instance = new constructor(consArgs);
						instance[fn].apply(instance, permutations[i]);
						instance.dispose();
					}
				});
			});
		},
		member : function(constructor, member, param, consArgs){
			it(member+" = "+param, function(){
				silenceWarning(function(){
					var permutations = generateArgs([param]);
					for (var i = 0; i < permutations.length; i++){
						var instance = new constructor(consArgs);
						instance[member] = permutations[i];
						instance.dispose();
					}
				});
			});
		},
		constructor : function(constructor, args){

			var argString;
			if (Array.isArray(args)){
				argString = args.join(", ");
			} else {
				argString = JSON.stringify(args);
			}

			it("constructor ( "+ argString + " )", function(){
				silenceWarning(function(){
					var permutations = generateArgs(args);
					for (var i = 0; i < permutations.length; i++){
						var Temp = function(){}; // temporary constructor
						Temp.prototype = constructor.prototype;
						var tmpInst = new Temp();
						constructor.apply(tmpInst, permutations[i]);
						tmpInst.dispose();
					}
				});
			});
		},
	};
});