openlayers/test/spec/ol/geom/flat/reverse.test.js

import {coordinates as reverseCoordinates} from '../../../../../src/ol/geom/flat/reverse.js';

describe('ol.geom.flat.reverse', function () {
  describe('ol.geom.flat.reverse.coordinates', function () {
    describe('with a stride of 2', function () {
      it('can reverse empty flat coordinates', function () {
        const flatCoordinates = [];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
        expect(flatCoordinates).to.be.empty();
      });

      it('can reverse one flat coordinates', function () {
        const flatCoordinates = [1, 2];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
        expect(flatCoordinates).to.eql([1, 2]);
      });

      it('can reverse two flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
        expect(flatCoordinates).to.eql([3, 4, 1, 2]);
      });

      it('can reverse three flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
        expect(flatCoordinates).to.eql([5, 6, 3, 4, 1, 2]);
      });

      it('can reverse four flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
        expect(flatCoordinates).to.eql([7, 8, 5, 6, 3, 4, 1, 2]);
      });
    });

    describe('with a stride of 3', function () {
      it('can reverse empty flat coordinates', function () {
        const flatCoordinates = [];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
        expect(flatCoordinates).to.be.empty();
      });

      it('can reverse one flat coordinates', function () {
        const flatCoordinates = [1, 2, 3];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
        expect(flatCoordinates).to.eql([1, 2, 3]);
      });

      it('can reverse two flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
        expect(flatCoordinates).to.eql([4, 5, 6, 1, 2, 3]);
      });

      it('can reverse three flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
        expect(flatCoordinates).to.eql([7, 8, 9, 4, 5, 6, 1, 2, 3]);
      });

      it('can reverse four flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
        expect(flatCoordinates).to.eql([10, 11, 12, 7, 8, 9, 4, 5, 6, 1, 2, 3]);
      });
    });

    describe('with a stride of 4', function () {
      it('can reverse empty flat coordinates', function () {
        const flatCoordinates = [];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
        expect(flatCoordinates).to.be.empty();
      });

      it('can reverse one flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
        expect(flatCoordinates).to.eql([1, 2, 3, 4]);
      });

      it('can reverse two flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
        expect(flatCoordinates).to.eql([5, 6, 7, 8, 1, 2, 3, 4]);
      });

      it('can reverse three flat coordinates', function () {
        const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
        expect(flatCoordinates).to.eql([9, 10, 11, 12, 5, 6, 7, 8, 1, 2, 3, 4]);
      });

      it('can reverse four flat coordinates', function () {
        const flatCoordinates = [
          1,
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9,
          10,
          11,
          12,
          13,
          14,
          15,
          16,
        ];
        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
        expect(flatCoordinates).to.eql([
          13,
          14,
          15,
          16,
          9,
          10,
          11,
          12,
          5,
          6,
          7,
          8,
          1,
          2,
          3,
          4,
        ]);
      });
    });
  });
});