Tone.js/test/component/Meter.js

define(["Tone/component/Meter", "helper/Basic", "helper/Offline", "Test",
	"Tone/signal/Signal", "helper/PassAudio", "Tone/type/Type",
	"Tone/component/Merge", "Tone/source/Oscillator", "helper/Supports"],
function (Meter, Basic, Offline, Test, Signal, PassAudio, Tone, Merge, Oscillator, Supports) {
	describe("Meter", function(){

		Basic(Meter);

		context("Metering", function(){
			if (Supports.ONLINE_TESTING) {
				it("handles input and output connections", function(){
					var meter = new Meter();
					Test.connect(meter);
					meter.connect(Test);
					meter.dispose();
				});

				it("handles getter/setter as Object", function(){
					var meter = new Meter();
					var values = {
						"smoothing" : 0.2
					};
					meter.set(values);
					expect(meter.get().smoothing).to.equal(0.2);
					meter.dispose();
				});

				it("can be constructed with an object", function(){
					var meter = new Meter({
						"smoothing" : 0.3
					});
					expect(meter.smoothing).to.equal(0.3);
					meter.dispose();
				});

				it("passes the audio through", function(){
					var meter;
					return PassAudio(function(input){
						meter = new Meter();
						input.chain(meter, Tone.Master);
					});
				});
			
				it("defaults to rms level of incoming signal", function(){
					var meter = new Meter();
					expect(meter.type).to.equal("rms");
					meter.dispose();
				});

				it("throws when invalid type is set", function(){
					var meter = new Meter();
					expect(function() {
						meter.type = "shouldThrow";
					}).to.throw("Tone.Meter: invalid type: shouldThrow");
					meter.dispose();

					expect(function(){
						new Meter({ type: "shouldThrow" });
					}).to.throw("Tone.Meter: invalid type: shouldThrow");
				});

				it("can change type", function(){
					var meter = new Meter();
					expect(meter.type).to.equal("rms");

					meter.type = "peak";
					expect(meter.type).to.equal("peak");

					meter.type = "rms";
					expect(meter.type).to.equal("rms");

					meter.dispose();
				});

				it("gets peak value correctly", function(){
					var values = [1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0, 9.0, -10.0];
					var meter = new Meter();
					var peak = meter.getPeakFloatValue(values);
					expect(peak).to.equal(10);

					meter.dispose();
				});

				// Based on https://rosettacode.org/wiki/Averages/Root_mean_square#JavaScript
				it("gets rms value correctly", function(){
					var values = [-1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0, -9.0, 10.0];
					var meter = new Meter();
					var peak = meter.getRmsFloatValue(values);
					expect(peak).to.be.closeTo(6.2048, 0.0001);

					meter.dispose();
				});

			
				it("measures the peak incoming signal", function(done){
					var meter = new Meter({ type: "peak" });
					var signal = new Signal(1).connect(meter);
					setTimeout(function(){
						expect(meter.getValue()).to.be.closeTo(1, 0.05);
						meter.dispose();
						signal.dispose();
						done();
					}, 400);
				});

				it("measures the rms incoming signal", function(done){
					var meter = new Meter({ type: "rms" });
					var signal = new Signal(1).connect(meter);
					setTimeout(function(){
						expect(meter.getValue()).to.be.closeTo(1, 0.05);
						meter.dispose();
						signal.dispose();
						done();
					}, 400);
				});

				it("can get the peak level of the incoming signal", function(done){
					var meter = new Meter({ type: "peak" });
					var osc = new Oscillator().connect(meter).start();
					osc.volume.value = -6;
					setTimeout(function(){
						expect(meter.getLevel()).to.be.closeTo(-6, 6);
						meter.dispose();
						osc.dispose();
						done();
					}, 400);
				});

				it("can get the rms level of the incoming signal", function(done){
					var meter = new Meter({ type: "rms" });
					var osc = new Oscillator().connect(meter).start();
					osc.volume.value = -6;
					setTimeout(function(){
						expect(meter.getLevel()).to.be.closeTo(-9, 1);
						meter.dispose();
						osc.dispose();
						done();
					}, 400);
				});
			}
		});
	});
});