/**
* Test utilities to generate GeoJSON data.
*
* @module server/spec/fixtures/geojson
*/
const _ = require('lodash');
const chance = require('chance').Chance();
/**
* Generates a GeoJSON point with random coordinates.
*
* const geoJsonFixtures = require('../spec/fixtures/geojson');
*
* geoJsonFixtures.point(); // { type: 'Point', coordinates: [ -76, 48 ] }
* geoJsonFixtures.point({ coordinates }); // { type: 'Point', coordinates: [ -76, 48 ] }
*
* @param {object} [data={}] - Custom point data.
* @param {object} [data.bbox] - A bounding box within which the generated point should be.
* @param {number[]} data.bbox.southWest - A longitude/latitude pair indicating the south-west corner of the bounding box.
* @param {number[]} data.bbox.northEast - A longitude/latitude pair indicating the north-east corner of the bounding box.
* @param {number[]} [data.coordinates] - The point's coordinates (longitude & latitude).
* @returns {object} A GeoJSON point.
*/
exports.point = function(data = {}) {
return {
type: 'Point',
coordinates: data.coordinates ? ensureCoordinates(data.coordinates) : exports.coordinates(_.pick(data, 'bbox'))
};
};
/**
* Generates a random pair of coordinates (longitude & latitude).
*
* const geoJsonFixtures = require('../spec/fixtures/geojson');
*
* geoJsonFixtures.coordinates(); // [ -76, 48 ]
*
* @param {object} [data={}] - Custom coordinates data.
* @param {object} [data.bbox] - A bounding box within which the generated coordinates should be.
* @param {number[]} data.bbox.southWest - A longitude/latitude pair indicating the south-west corner of the bounding box.
* @param {number[]} data.bbox.northEast - A longitude/latitude pair indicating the north-east corner of the bounding box.
* @returns {number[]} A GeoJSON coordinates pair.
*/
exports.coordinates = function(data = {}) {
let minLatitude = -90;
let maxLatitude = 90;
let minLongitude = -180;
let maxLongitude = 180;
if (data.bbox) {
const bbox = ensureBbox(data.bbox);
minLatitude = bbox.southWest[1];
maxLatitude = bbox.northEast[1];
minLongitude = bbox.southWest[0];
maxLongitude = bbox.northEast[0];
}
return [
chance.floating({ min: minLongitude, max: maxLongitude }),
chance.floating({ min: minLatitude, max: maxLatitude })
];
};
function ensureBbox(bbox) {
if (!_.isObject(bbox)) {
throw new Error('Bounding box must be an object');
} else if (!bbox.southWest) {
throw new Error('Bounding box must have a "southWest" property');
} else if (!bbox.northEast) {
throw new Error('Bounding box must have a "northEast" property');
}
ensureCoordinates(bbox.southWest);
ensureCoordinates(bbox.northEast);
return bbox;
}
function ensureCoordinates(coordinates) {
if (!_.isArray(coordinates)) {
throw new Error(`Coordinates must be an array, got ${typeof(coordinates)}`);
} else if (coordinates.length != 2) {
throw new Error(`Coordinates must be an array with 2 elements, but it has length ${coordinates.length}`);
}
const nan = coordinates.find(value => !_.isFinite(value))
if (nan !== undefined) {
throw new Error(`Coordinates must contain only numbers, got ${typeof(nan)}`);
}
const longitude = coordinates[0];
if (longitude < -180 || longitude > 180) {
throw new Error(`Longitude must be between -180 and 180, got ${longitude}`);
}
const latitude = coordinates[1];
if (latitude < -90 || latitude > 90) {
throw new Error(`Latitude must be between -90 and 90, got ${latitude}`);
}
return coordinates;
}
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