Tone.js/Tone/effect/Tremolo.test.ts

import { Tremolo } from "./Tremolo";
import { BasicTests } from "test/helper/Basic";
import { EffectTests } from "test/helper/EffectTests";
import { Offline } from "test/helper/Offline";
import { expect } from "chai";
import { CompareToFile } from "test/helper/CompareToFile";
import { Oscillator } from "Tone/source";

describe("Tremolo", () => {
	BasicTests(Tremolo);
	EffectTests(Tremolo);

	it("matches a file", () => {
		return CompareToFile(() => {
			const tremolo = new Tremolo().toDestination().start(0.2);
			const osc = new Oscillator().connect(tremolo).start();
		}, "tremolo.wav", 0.01);
	});

	context("API", () => {

		it("can pass in options in the constructor", () => {
			const tremolo = new Tremolo({
				depth: 0.2,
				type: "sawtooth",
				spread: 160,
			});
			expect(tremolo.depth.value).to.be.closeTo(0.2, 0.001);
			expect(tremolo.type).to.equal("sawtooth");
			expect(tremolo.spread).to.equal(160);
			tremolo.dispose();
		});

		it("can be started and stopped", () => {
			const tremolo = new Tremolo();
			tremolo.start().stop("+0.2");
			tremolo.dispose();
		});

		it("can get/set the options", () => {
			const tremolo = new Tremolo();
			tremolo.set({
				frequency: 2.4,
				type: "triangle"
			});
			expect(tremolo.get().frequency).to.be.closeTo(2.4, 0.01);
			expect(tremolo.get().type).to.equal("triangle");
			tremolo.dispose();
		});

		it("can set the frequency and depth", () => {
			const tremolo = new Tremolo();
			tremolo.depth.value = 0.4;
			tremolo.frequency.value = 0.4;
			expect(tremolo.depth.value).to.be.closeTo(0.4, 0.01);
			expect(tremolo.frequency.value).to.be.closeTo(0.4, 0.01);
			tremolo.dispose();
		});

		it("can sync the frequency to the transport", () => {

			return Offline(({ transport }) => {
				const tremolo = new Tremolo(2);
				tremolo.sync();
				tremolo.frequency.toDestination();
				transport.bpm.setValueAtTime(transport.bpm.value * 2, 0.05);
			}, 0.1).then((buffer) => {
				expect(buffer.getValueAtTime(0)).to.be.closeTo(2, 0.1);
				expect(buffer.getValueAtTime(0.05)).to.be.closeTo(4, 0.1);
			});
		});

		it("can unsync the frequency to the transport", () => {

			return Offline(({ transport }) => {
				const tremolo = new Tremolo(2);
				tremolo.sync();
				tremolo.frequency.toDestination();
				transport.bpm.setValueAtTime(transport.bpm.value * 2, 0.05);
				tremolo.unsync();
			}, 0.1).then((buffer) => {
				expect(buffer.getValueAtTime(0)).to.be.closeTo(2, 0.1);
				expect(buffer.getValueAtTime(0.05)).to.be.closeTo(2, 0.1);
			});
		});
	});
});