Tone.js/Tone/effect/FrequencyShifter.test.ts

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

describe("FrequencyShifter", () => {

	BasicTests(FrequencyShifter);

	it("matches a file", () => {
		return CompareToFile(() => {
			const shifter = new FrequencyShifter().toDestination();
			shifter.frequency.value = -60;
			const osc = new Oscillator().connect(shifter);
			osc.start(0);
		}, "frequencyShifter.wav", 0.1);
	});

	context("API", () => {

		it("can pass in options in the constructor", () => {
			const shifter = new FrequencyShifter({
				frequency : -20,
			});
			expect(shifter.frequency.value).to.be.closeTo(-20, 0.001);
			shifter.dispose();
		});

		it("can get/set the options", () => {
			const shifter = new FrequencyShifter();
			shifter.set({
				frequency : 40,
			});
			expect(shifter.get().frequency).to.be.closeTo(40, 0.001);
			shifter.dispose();
		});

		it("passes audio from input to output", () => {
			return Offline(() => {
				const osc = new Oscillator();
				osc.start(0).stop(0.1);
				const shifter = new FrequencyShifter(0.2).toDestination();
				osc.connect(shifter);
			}, 0.3).then((buffer) => {
				expect(buffer.getRmsAtTime(0.05)).to.be.greaterThan(0);
				expect(buffer.getRmsAtTime(0.1)).to.be.greaterThan(0);
				expect(buffer.getRmsAtTime(0.2)).to.be.greaterThan(0);
			});
		});
	});
});