avocado/packages/timing/test/lfo.js

import {expect} from 'chai';

import LfoResult from '../src/lfo/result';

it('can do linear oscillation', () => {
  const object = {x: 0};
  const result = new LfoResult(
    object,
    {
      x: {
        frequency: 1,
        magnitude: 100,
        median: 50,
      },
    },
  );
  result.tick(0.1);
  expect(object.x).to.be.closeTo(70, 0.001);
  result.tick(0.5);
  expect(object.x).to.be.closeTo(30, 0.001);
  result.tick(0.25);
  expect(object.x).to.be.closeTo(20, 0.001);
  result.tick(0.4);
  expect(object.x).to.be.closeTo(100, 0.001);
});