Tone.js/test/event/Pattern.js

define(["helper/Basic", "Tone/event/Pattern", "Tone/core/Tone", "Tone/core/Transport", "helper/Offline", "Tone/type/Time"],
	function (Basic, Pattern, Tone, Transport, Offline, Time) {

	describe("Pattern", function(){

		Basic(Pattern);

		context("Constructor", function(){

			it ("takes a callback, an array of values and a pattern name", function(){
				return Offline(function(){
					var callback = function(){};
					var pattern = new Pattern(callback, [0, 1, 2, 3], "down");
					expect(pattern.callback).to.equal(callback);
					expect(pattern.values).to.deep.equal([0, 1, 2, 3]);
					expect(pattern.pattern).to.equal("down");
					pattern.dispose();
				});
			});

			it ("can be constructed with no arguments", function(){
				return Offline(function(){
					var pattern = new Pattern();
					pattern.dispose();
				});
			});

			it ("can pass in arguments in options object", function(){
				return Offline(function(){
					var callback = function(){};
					var pattern = new Pattern({
						"callback" : callback,
						"iterations" : 4,
						"probability" : 0.3,
						"interval" : "8t",
						"values" : [1, 2, 3],
						"pattern" : "upDown"
					});
					expect(pattern.callback).to.equal(callback);
					expect(pattern.interval.valueOf()).to.equal(Time("8t").valueOf());
					expect(pattern.iterations).to.equal(4);
					expect(pattern.values).to.deep.equal([1, 2, 3]);
					expect(pattern.probability).to.equal(0.3);
					expect(pattern.pattern).to.equal("upDown");
					pattern.dispose();
				});
			});
		});

		context("Get/Set", function(){

			it ("can set values with object", function(){
				return Offline(function(){
					var callback = function(){};
					var pattern = new Pattern();
					pattern.set({
						"callback" : callback,
						"values" : ["a", "b", "c"],
						"index" : 2
					});
					expect(pattern.callback).to.equal(callback);
					expect(pattern.values).to.deep.equal(["a", "b", "c"]);
					expect(pattern.index).to.equal(2);
					pattern.dispose();
				});
			});

			it ("can set get a the values as an object", function(){
				return Offline(function(){
					var callback = function(){};
					var pattern = new Pattern({
						"callback" : callback,
						"pattern" : "random",
						"probability" : 0.3,
					});
					var values = pattern.get();
					expect(values.pattern).to.equal("random");
					expect(values.probability).to.equal(0.3);
					pattern.dispose();
				});
			});
		});


		context("Callback", function(){

			it ("is invoked after it's started", function(){
				var invoked = false;
				return Offline(function(Transport){
					new Pattern(function(){
						invoked = true;
					}, [0, 1, 2]).start(0);
					Transport.start();
				}, 0.2).then(function(){
					expect(invoked).to.be.true;
				});
			});

			it ("passes in the scheduled time and pattern index to the callback", function(){
				var invoked = false;
				return Offline(function(Transport){
					var startTime = 0.05;
					var pattern = new Pattern(function(time, note){
						expect(time).to.be.a.number;
						expect(time - startTime).to.be.closeTo(0.3, 0.01);
						expect(note).to.be.equal("a");
						invoked = true;
					}, ["a"], "up");
					Transport.start(startTime);
					pattern.start(0.3);
				}, 0.4).then(function(){
					expect(invoked).to.be.true;
				});
			});

			it ("passes in the next note of the pattern", function(){
				var counter = 0;
				return Offline(function(Transport){
					var pattern = new Pattern(function(time, note){
						expect(note).to.equal(counter % 3);
						counter++;
					}, [0, 1, 2], "up").start(0);
					pattern.interval = "16n";
					Transport.start(0);
				}, 0.7).then(function(){
					expect(counter).to.equal(6);
				});
			});
		});

	});
});