openlayers/test/browser/spec/ol/format/topojson.test.js

import Feature from '../../../../../src/ol/Feature.js';
import FeatureFormat from '../../../../../src/ol/format/Feature.js';
import MultiPolygon from '../../../../../src/ol/geom/MultiPolygon.js';
import Polygon from '../../../../../src/ol/geom/Polygon.js';
import TopoJSON from '../../../../../src/ol/format/TopoJSON.js';
import {transform} from '../../../../../src/ol/proj.js';

const aruba = {
  type: 'Topology',
  transform: {
    scale: [0.036003600360036005, 0.017361589674592462],
    translate: [-180, -89.99892578124998],
  },
  objects: {
    aruba: {
      type: 'Polygon',
      properties: {
        prop0: 'value0',
      },
      arcs: [[0]],
      id: 533,
    },
  },
  arcs: [
    [
      [3058, 5901],
      [0, -2],
      [-2, 1],
      [-1, 3],
      [-2, 3],
      [0, 3],
      [1, 1],
      [1, -3],
      [2, -5],
      [1, -1],
    ],
  ],
};

const zeroId = {
  type: 'Topology',
  objects: {
    foobar: {
      type: 'Point',
      id: 0,
      coordinates: [0, 42],
    },
  },
};

const nullGeometry = {
  type: 'Topology',
  objects: {
    foobar: {
      type: null,
      properties: {
        prop0: 'value0',
      },
      id: 533,
    },
  },
};

describe('ol.format.TopoJSON', function () {
  let format;
  before(function () {
    format = new TopoJSON();
  });

  describe('constructor', function () {
    it('creates a new format', function () {
      expect(format).to.be.a(FeatureFormat);
      expect(format).to.be.a(TopoJSON);
    });
  });

  describe('#readFeaturesFromTopology_()', function () {
    it('creates an array of features from a topology', function () {
      const features = format.readFeaturesFromObject(aruba);
      expect(features).to.have.length(1);

      const feature = features[0];
      expect(feature).to.be.a(Feature);

      const geometry = feature.getGeometry();
      expect(geometry).to.be.a(Polygon);

      // Parses identifier
      expect(feature.getId()).to.be(533);
      // Parses properties
      expect(feature.get('prop0')).to.be('value0');

      expect(geometry.getExtent()).to.eql([
        -70.08100810081008,
        12.417091709170947,
        -69.9009900990099,
        12.608069195591469,
      ]);
    });

    it('can read a feature with id equal to 0', function () {
      const features = format.readFeaturesFromObject(zeroId);
      expect(features).to.have.length(1);

      const feature = features[0];
      expect(feature).to.be.a(Feature);
      expect(feature.getId()).to.be(0);
    });

    it('can read a feature with null geometry', function () {
      const features = format.readFeaturesFromObject(nullGeometry);
      expect(features).to.have.length(1);

      const feature = features[0];
      expect(feature).to.be.a(Feature);
      expect(feature.getGeometry()).to.be(null);
      expect(feature.getId()).to.be(533);
      expect(feature.get('prop0')).to.be('value0');
    });
  });

  describe('#readFeatures()', function () {
    it('parses simple.json', function (done) {
      afterLoadText('spec/ol/format/topojson/simple.json', function (text) {
        const features = format.readFeatures(text);
        expect(features.length).to.be(3);

        const point = features[0].getGeometry();
        expect(point.getType()).to.be('Point');
        expect(point.getFlatCoordinates()).to.eql([102, 0.5]);

        const line = features[1].getGeometry();
        expect(line.getType()).to.be('LineString');
        expect(line.getFlatCoordinates()).to.eql([
          102,
          0,
          103,
          1,
          104,
          0,
          105,
          1,
        ]);

        const polygon = features[2].getGeometry();
        expect(polygon.getType()).to.be('Polygon');
        expect(polygon.getFlatCoordinates()).to.eql([
          100,
          0,
          100,
          1,
          101,
          1,
          101,
          0,
          100,
          0,
        ]);

        done();
      });
    });

    it('parses simple.json and transforms', function (done) {
      afterLoadText('spec/ol/format/topojson/simple.json', function (text) {
        const features = format.readFeatures(text, {
          featureProjection: 'EPSG:3857',
        });
        expect(features.length).to.be(3);

        const point = features[0].getGeometry();
        expect(point.getType()).to.be('Point');
        expect(features[0].getGeometry().getCoordinates()).to.eql(
          transform([102.0, 0.5], 'EPSG:4326', 'EPSG:3857')
        );

        const line = features[1].getGeometry();
        expect(line.getType()).to.be('LineString');
        expect(line.getCoordinates()).to.eql([
          transform([102.0, 0.0], 'EPSG:4326', 'EPSG:3857'),
          transform([103.0, 1.0], 'EPSG:4326', 'EPSG:3857'),
          transform([104.0, 0.0], 'EPSG:4326', 'EPSG:3857'),
          transform([105.0, 1.0], 'EPSG:4326', 'EPSG:3857'),
        ]);

        const polygon = features[2].getGeometry();
        expect(polygon.getType()).to.be('Polygon');
        expect(polygon.getCoordinates()).to.eql([
          [
            transform([100.0, 0.0], 'EPSG:4326', 'EPSG:3857'),
            transform([100.0, 1.0], 'EPSG:4326', 'EPSG:3857'),
            transform([101.0, 1.0], 'EPSG:4326', 'EPSG:3857'),
            transform([101.0, 0.0], 'EPSG:4326', 'EPSG:3857'),
            transform([100.0, 0.0], 'EPSG:4326', 'EPSG:3857'),
          ],
        ]);

        done();
      });
    });

    it('parses world-110m.json', function (done) {
      afterLoadText('spec/ol/format/topojson/world-110m.json', function (text) {
        const features = format.readFeatures(text);
        expect(features.length).to.be(178);

        const first = features[0];
        expect(first).to.be.a(Feature);
        const firstGeom = first.getGeometry();
        expect(firstGeom).to.be.a(MultiPolygon);
        expect(firstGeom.getExtent()).to.eql([
          -180,
          -85.60903777459777,
          180,
          83.64513000000002,
        ]);

        const last = features[177];
        expect(last).to.be.a(Feature);
        const lastGeom = last.getGeometry();
        expect(lastGeom).to.be.a(Polygon);
        expect(lastGeom.getExtent()).to.eql([
          25.26325263252633,
          -22.271802279310577,
          32.848528485284874,
          -15.50833810039586,
        ]);

        done();
      });
    });

    it("sets the topology's child names as feature property", function (done) {
      afterLoadText('spec/ol/format/topojson/world-110m.json', function (text) {
        const format = new TopoJSON({
          layerName: 'layer',
        });
        const features = format.readFeatures(text);
        expect(features[0].get('layer')).to.be('land');
        expect(features[177].get('layer')).to.be('countries');
        done();
      });
    });

    it("only parses features from specified topology's children", function (done) {
      afterLoadText('spec/ol/format/topojson/world-110m.json', function (text) {
        const format = new TopoJSON({
          layers: ['land'],
        });
        const features = format.readFeatures(text);
        expect(features.length).to.be(1);
        done();
      });
    });
  });
});