test/core/util.spec.js

/**
 * @file utils.js
 * Tests the user-facing API, ensuring the object functions while not exposing private members.
 */

import util from './../../src/core/util.js';

/** @test {util} */
describe('util', function () {
  it('should be instantiated', function () {
    expect(util).to.not.equal(null);
  });
});

/** @test {util.normalizeEvent} */
describe('util.normalizeEvent', function () {
  it('should expect to emit start', function () {
    expect(util.normalizeEvent('mousedown')).to.equal('start');
    expect(util.normalizeEvent('touchstart')).to.equal('start');
  });

  it('should expect to emit move', function () {
    expect(util.normalizeEvent('mousemove')).to.equal('move');
    expect(util.normalizeEvent('touchmove')).to.equal('move');
  });

  it('should expect to emit end', function () {
    expect(util.normalizeEvent('mouseup')).to.equal('end');
    expect(util.normalizeEvent('touchend')).to.equal('end');
  });

  it('should expect to emit null for unknown events', function () {
    expect(util.normalizeEvent('foobar')).to.be.null;
  });
});

/** @test {util.isWithin} */
describe('util.isWithin', function () {

  it('should expect be true when points are within a tolerance', function () {
    expect(util.isWithin(0, 0, 0, 0, 10)).to.be.true;
    expect(util.isWithin(10, 10, 10, 10, 0)).to.be.true;
    expect(util.isWithin(0, -10, 9, 0, 10)).to.be.true;
  });

  it('should expect be false when points are outside a tolerance', function () {
    expect(util.isWithin(0, 0, 0, 0, -1)).to.be.false;
    expect(util.isWithin(10, 10, 20, 20, 0)).to.be.false;
  });
});

/** @test {util.distanceBetweenTwoPoints} */
describe('util.distanceBetweenTwoPoints', function () {
  it('should return a distance of 5', function () {
    expect(util.distanceBetweenTwoPoints(0, 4, 0, 3)).to.equal(5);
  });

  it('should return a distance of 0', function () {
    expect(util.distanceBetweenTwoPoints(0, 0, 0, 0)).to.equal(0);
  });

  it('should return a distance of 0', function () {
    expect(util.distanceBetweenTwoPoints('foo', 0, 0, 0)).to.be.NaN;
  });
});

/** @test {util.getAngle} */
describe('util.getAngle', function () {

  it('should return an angle of 45', function () {
    expect(util.getAngle(0, 0, 3, 3)).to.equal(315);
  });

  it('should return an angle of 360', function () {
    expect(util.getAngle(0, 0, 0, 0)).to.equal(360);
  });

  it('should return an angle of 180', function () {
    expect(util.getAngle(0, 0, -3, 0)).to.equal(180);
  });
});

/** @test {util.getAngularDistance} */
describe('util.getAngularDistance', function () {

  it('should return an angle of 45', function () {
    expect(util.getAngularDistance(270, 360)).to.equal(-90);
  });

  it('should return an angle of -15', function () {
    expect(util.getAngularDistance(5, 350)).to.equal(-15);
  });

  it('should return an angle of +15', function () {
    expect(util.getAngularDistance(350, 5)).to.equal(15);
  });

  it('should return an angle of 0', function () {
    expect(util.getAngularDistance(360, 360)).to.equal(0);
  });
});