freesewing/tests/point.test.js

var expect = require('chai').expect;
var Point = require('../dist/lib/point').Point;


it('should return point object', () => {
  let result = new Point(2,4);
  expect(result).to.be.a('object');
  expect(result.x).to.equal(2);
  expect(result.y).to.equal(4);
});

it('should limit point precision', () => {
  let result = new Point(2.12345,4.98765);
  expect(result.x).to.equal(2.12);
  expect(result.y).to.equal(4.99);
});

it('should return distance', () => {
  expect(new Point(2,4).dist(new Point(-123, -32423))).to.equal(32427.24);
});

it('should return slope', () => {
  let from = new Point(0,0);
  expect(from.slope(new Point(  0, -10))).to.equal(-Infinity);
  expect(from.slope(new Point( 10,   0))).to.equal(0);
  expect(from.slope(new Point(  0,  10))).to.equal(Infinity);
  expect(from.slope(new Point(-10,   0))).to.equal(-0);
  expect(from.slope(new Point( 10,  10))).to.equal(1);
  expect(from.slope(new Point(-10,   5))).to.equal(-0.5);
});

it('should return angle', () => {
  let from = new Point(0,0);
  expect(from.angle(new Point( 10,   0))).to.equal(0);
  expect(from.angle(new Point(-20,   0))).to.equal(180);
  expect(from.angle(new Point(  0, -10))).to.equal(90);
  expect(from.angle(new Point(  0,  10))).to.equal(270);
  expect(from.angle(new Point( 10, -10))).to.equal(45);
  expect(from.angle(new Point( 10,  10))).to.equal(315);
});

it('should copy a point', () => {
  let result = new Point(2,4).copy();
  expect(result.x).to.equal(2);
  expect(result.y).to.equal(4);
});

it('should check points for equality', () => {
  let a = new Point(-123,456);
  let b = new Point(-123,456);
  expect(a).to.deep.equal(b);
});

it('should flip point around X value', () => {
  let result = new Point(2,4).flipX(new Point(-20, 4));
  expect(result.x).to.equal(-42);
  expect(result.y).to.equal(4);
});

it('should flip point around Y value', () => {
  let result = new Point(2,4).flipY(new Point(2, -14));
  expect(result.x).to.equal(2);
  expect(result.y).to.equal(-32);
});

it('should shift a point', () => {
  let origin = new Point(0,0);
  let n = origin.shift(90, 10);
  let e = origin.shift(0, 10);
  let s = origin.shift(270, 10);
  let w = origin.shift(180, 10);
  expect(n.x).to.equal(0);
  expect(n.y).to.equal(-10);
  expect(e.x).to.equal(10);
  expect(e.y).to.equal(0);
  expect(s.x).to.equal(0);
  expect(s.y).to.equal(10);
  expect(w.x).to.equal(-10);
  expect(w.y).to.equal(0);
  let rand = origin.shift(-123, 456);
  expect(rand.x).to.equal(-248.36);
  expect(rand.y).to.equal(382.43);
});

it('should shift a point towards another', () => {
  let origin = new Point(0,0);
  let n = new Point(  0, -10);
  let e = new Point( 10,   0);
  let s = new Point(  0,  10);
  let w = new Point(-10,   0);
  let sn = origin.shiftTowards(n, 123);
  let se = origin.shiftTowards(e, 123);
  let ss = origin.shiftTowards(s, 123);
  let sw = origin.shiftTowards(w, 123);
  expect(sn.x).to.equal(0);
  expect(sn.y).to.equal(-123);
  expect(se.x).to.equal(123);
  expect(se.y).to.equal(0);
  expect(ss.x).to.equal(0);
  expect(ss.y).to.equal(123);
  expect(sw.x).to.equal(-123);
  expect(sw.y).to.equal(0);
  expect(sw.shiftTowards(sn, 100).x).to.equal(-52.29);
  expect(ss.shiftTowards(se, 200).y).to.equal(-18.42);
});

it('should shift a point a fraction towards another', () => {
  let origin = new Point(0,0);
  let n = new Point(  0, -10);
  let e = new Point( 10,   0);
  let s = new Point(  0,  10);
  let w = new Point(-10,   0);
  let sn = origin.shiftFractionTowards(n, 1.5);
  let se = origin.shiftFractionTowards(e, 1.5);
  let ss = origin.shiftFractionTowards(s, 0.5);
  let sw = origin.shiftFractionTowards(w, 2.5);
  expect(sn.x).to.equal(0);
  expect(sn.y).to.equal(-15);
  expect(se.x).to.equal(15);
  expect(se.y).to.equal(0);
  expect(ss.x).to.equal(0);
  expect(ss.y).to.equal(5);
  expect(sw.x).to.equal(-25);
  expect(sw.y).to.equal(0);
  expect(sw.shiftFractionTowards(sn, 100).x).to.equal(2474.59);
  expect(ss.shiftFractionTowards(se, 200).y).to.equal(-994.91);
});

it('should shift a point beyond another', () => {
  let origin = new Point(0,0);
  let n = new Point(  0, -10);
  let e = new Point( 10,   0);
  let s = new Point(  0,  10);
  let w = new Point(-10,   0);
  let sn = origin.shiftOutwards(n, 100);
  let se = origin.shiftOutwards(e, 100);
  let ss = origin.shiftOutwards(s, 100);
  let sw = origin.shiftOutwards(w, 100);
  expect(sn.x).to.equal(0);
  expect(sn.y).to.equal(-110);
  expect(se.x).to.equal(110);
  expect(se.y).to.equal(0);
  expect(ss.x).to.equal(0);
  expect(ss.y).to.equal(110);
  expect(sw.x).to.equal(-110);
  expect(sw.y).to.equal(0);
  expect(sw.shiftOutwards(sn, 100).x).to.equal(70.71);
  expect(ss.shiftOutwards(se, 200).y).to.equal(-141.42);
});