Tone.js/test/helper/EffectTests.js

define(["helper/OutputAudio", "Tone/effect/Effect", "helper/PassAudio",
	"helper/PassAudioStereo", "helper/Test", "helper/Offline", "Tone/signal/Signal", "Tone/component/Merge"],
function(OutputAudio, Effect, PassAudio, PassAudioStereo, Test, Offline, Signal, Merge){

	return function(Constr, args, before){

		context("Effect Tests", function(){

			it("extends Tone.Effect", function(){
				var instance = new Constr(args);
				expect(instance).to.be.an.instanceof(Effect);
				instance.dispose();
			});

			it("has an input and output", function(){
				var instance = new Constr(args);
				if (before){
					before(instance);
				}
				instance.connect(Test);
				Test.connect(instance);
				instance.dispose();
			});

			it("can set the dry/wet value", function(){
				var instance = new Constr(args);
				if (before){
					before(instance);
				}
				instance.wet.value = 0;
				expect(instance.wet.value).to.equal(0);
				instance.wet.value = 0.5;
				expect(instance.wet.value).to.equal(0.5);
				instance.dispose();
			});

			it("can be constructed with an object", function(){
				var instance = new Constr({
					"wet" : "0.25"
				});
				if (before){
					before(instance);
				}
				expect(instance.wet.value).to.equal(0.25);
				instance.dispose();
			});

			it("passes audio from input to output", function(){
				return PassAudio(function(input){
					var instance = new Constr(args);
					if (before){
						before(instance);
					}
					input.connect(instance);
					instance.toMaster();
				});
			});

			it("passes audio in both channels", function(){
				return PassAudioStereo(function(input){
					var instance = new Constr(args);
					if (before){
						before(instance);
					}
					input.connect(instance);
					instance.toMaster();
				});
			});

			it("can pass 100% dry signal", function(){
				return Offline(function(){
					var instance = new Constr(args).toMaster();
					if (before){
						before(instance);
					}
					var merge = new Merge().connect(instance);
					var signalL = new Signal(-1).connect(merge.left);
					var signalR = new Signal(1).connect(merge.right);
					//make the signals ramp
					signalL.linearRampTo(1, 1);
					signalR.linearRampTo(-1, 1);
					instance.wet.value = 0;
				}, 0.5, 2).then(function(buffer){
					buffer.forEach(function(L, R, time){
						var leftValue = (time * 2) - 1;
						var rightValue = ((1 - time) * 2) - 1;
						expect(L).to.be.closeTo(leftValue, 0.001);
						expect(R).to.be.closeTo(rightValue, 0.001);
					});
				});
			});

			it("effects the incoming signal", function(){
				return Offline(function(){
					var instance = new Constr(args).toMaster();
					if (before){
						before(instance);
					}
					var merge = new Merge().connect(instance);
					var signalL = new Signal(-1).connect(merge.left);
					var signalR = new Signal(1).connect(merge.right);
					//make the signals ramp
					signalL.linearRampTo(1, 1);
					signalR.linearRampTo(-1, 1);
					if (instance.start){
						instance.start();
					}
				}, 0.5, 2).then(function(buffer){
					var leftEffected = false;
					var rightEffected = false;
					buffer.forEach(function(L, R, time){
						var leftValue = (time * 2) - 1;
						var rightValue = ((1 - time) * 2) - 1;
						if (Math.abs(L - leftValue) > 0.01){
							leftEffected = true;
						}
						if (Math.abs(R - rightValue) > 0.01){
							rightEffected = true;
						}
					});
					expect(leftEffected).to.be.true;
					expect(rightEffected).to.be.true;
				});
			});
		});

	};
});