paper.js/test/tests/CurveLocation.js

/*
 * Paper.js - The Swiss Army Knife of Vector Graphics Scripting.
 * http://paperjs.org/
 *
 * Copyright (c) 2011 - 2020, Jürg Lehni & Jonathan Puckey
 * http://juerglehni.com/ & https://puckey.studio/
 *
 * Distributed under the MIT license. See LICENSE file for details.
 *
 * All rights reserved.
 */

QUnit.module('CurveLocation');

test('CurveLocation#offset', function() {
    var path = new Path();
    path.add(new Point(100, 100));
    path.add(new Point(200, 100));
    path.add(new Point(300, 100));
    path.add(new Point(400, 100));

    for (var i = 0; i < 4; i++) {
        equals(path.segments[i].location.offset, i * 100);
    }
});