Add precision parameter to all toGeoJSON functions (#5444)

* Add precision parameter to all toGeoJSON functions

* Replace usage of toPrecision with Utils.formatNum

* Always default to six decimal places

* Fix docs

* Allow precision of 0

spec/suites/layer/GeoJSONSpec.js

@@ -73,6 +73,14 @@ describe("L.Marker#toGeoJSON", function () {
 			coordinates: [20, 10, 30]
 		});
 	});
+
+	it('should allow specific precisions', function () {
+		var marker = new L.Marker([10.123456, 20.123456, 30.123456]);
+		expect(marker.toGeoJSON(3).geometry).to.eql({
+			type: 'Point',
+			coordinates: [20.123, 10.123, 30.123]
+		});
+	});
 });
 
 describe("L.Circle#toGeoJSON", function () {
@@ -91,6 +99,14 @@ describe("L.Circle#toGeoJSON", function () {
 			coordinates: [20, 10, 30]
 		});
 	});
+
+	it('should allow specific precisions', function () {
+		var circle = new L.Circle([10.1234, 20.1234, 30.1234], 100);
+		expect(circle.toGeoJSON(3).geometry).to.eql({
+			type: 'Point',
+			coordinates: [20.123, 10.123, 30.123]
+		});
+	});
 });
 
 describe("L.CircleMarker#toGeoJSON", function () {
@@ -109,6 +125,14 @@ describe("L.CircleMarker#toGeoJSON", function () {
 			coordinates: [20, 10, 30]
 		});
 	});
+
+	it("should allow specific precisions", function () {
+		var marker = new L.CircleMarker([10.1234, 20.1234]);
+		expect(marker.toGeoJSON(3).geometry).to.eql({
+			type: 'Point',
+			coordinates: [20.123, 10.123]
+		});
+	});
 });
 
 describe("L.Polyline#toGeoJSON", function () {
@@ -127,6 +151,14 @@ describe("L.Polyline#toGeoJSON", function () {
 			coordinates: [[20, 10, 30], [5, 2, 10]]
 		});
 	});
+
+	it("should allow specific precisions", function () {
+		var polyline = new L.Polyline([[10.1234, 20.1234, 30.1234], [2.1234, 5.1234, 10.1234]]);
+		expect(polyline.toGeoJSON(3).geometry).to.eql({
+			type: 'LineString',
+			coordinates: [[20.123, 10.123, 30.123], [5.123, 2.123, 10.123]]
+		});
+	});
 });
 
 describe("L.Polyline (multi) #toGeoJSON", function () {
@@ -151,6 +183,17 @@ describe("L.Polyline (multi) #toGeoJSON", function () {
 			]
 		});
 	});
+
+	it("should allow specific precisions", function () {
+		var multiPolyline = new L.Polyline([[[10.1234, 20.1234, 30.1234], [2.1234, 5.1234, 10.1234]], [[1.1234, 2.1234, 3.1234], [4.1234, 5.1234, 6.1234]]]);
+		expect(multiPolyline.toGeoJSON(3).geometry).to.eql({
+			type: 'MultiLineString',
+			coordinates: [
+				[[20.123, 10.123, 30.123], [5.123, 2.123, 10.123]],
+				[[2.123, 1.123, 3.123], [5.123, 4.123, 6.123]]
+			]
+		});
+	});
 });
 
 describe("L.Polygon#toGeoJSON", function () {
@@ -212,6 +255,13 @@ describe("L.Polygon#toGeoJSON", function () {
 		});
 	});
 
+	it("should allow specific precisions", function () {
+		var polygon = new L.Polygon([[1.1234, 2.1234], [3.1234, 4.1234], [5.1234, 6.1234]]);
+		expect(polygon.toGeoJSON(3).geometry).to.eql({
+			type: 'Polygon',
+			coordinates: [[[2.123, 1.123], [4.123, 3.123], [6.123, 5.123], [2.123, 1.123]]]
+		});
+	});
 });
 
 describe("L.Polygon (multi) #toGeoJSON", function () {
@@ -256,6 +306,15 @@ describe("L.Polygon (multi) #toGeoJSON", function () {
 		});
 	});
 
+	it("should allow specific precisions", function () {
+		var multiPolygon = new L.Polygon([[[[1.1234, 2.1234], [3.1234, 4.1234], [5.1234, 6.1234]]]]);
+		expect(multiPolygon.toGeoJSON(3).geometry).to.eql({
+			type: 'MultiPolygon',
+			coordinates: [
+				[[[2.123, 1.123], [4.123, 3.123], [6.123, 5.123], [2.123, 1.123]]]
+			]
+		});
+	});
 });
 
 describe("L.LayerGroup#toGeoJSON", function () {
@@ -327,10 +386,29 @@ describe("L.LayerGroup#toGeoJSON", function () {
 			}]
 		};
 
-		expect(L.geoJSON(json).toGeoJSON()).to.eql(json);
+		var expected = {
+			"type": "FeatureCollection",
+			"features": [{
+				"type": "Feature",
+				"geometry": {
+					"type": "GeometryCollection",
+					"geometries": [{
+						"type": "LineString",
+						"coordinates": [[-122.442559, 37.806664], [-122.442838, 37.806636]]
+					}, {
+						"type": "LineString",
+						"coordinates": [[-122.442551, 37.806626], [-122.442834, 37.8066]]
+					}]
+				},
+				"properties": {
+					"name": "SF Marina Harbor Master"
+				}
+			}]
+		};
+		expect(L.geoJSON(json).toGeoJSON()).to.eql(expected);
 	});
 
-	it('roundtrips MiltiPoint features', function () {
+	it('roundtrips MultiPoint features', function () {
 		var json = {
 			"type": "FeatureCollection",
 			"features": [{
@@ -345,7 +423,20 @@ describe("L.LayerGroup#toGeoJSON", function () {
 			}]
 		};
 
-		expect(L.geoJSON(json).toGeoJSON()).to.eql(json);
+		var expected = {
+			"type": "FeatureCollection",
+			"features": [{
+				"type": "Feature",
+				"geometry": {
+					"type": "MultiPoint",
+					"coordinates": [[-122.442559, 37.806664], [-122.442838, 37.806636]]
+				},
+				"properties": {
+					"name": "Test MultiPoints"
+				}
+			}]
+		};
+		expect(L.geoJSON(json).toGeoJSON()).to.eql(expected);
 	});
 
 	it("omits layers which do not implement toGeoJSON", function () {
@@ -369,4 +460,14 @@ describe("L.LayerGroup#toGeoJSON", function () {
 		expect(geoJSON.features[0].type).to.eql("Feature");
 		expect(geoJSON.features[1].type).to.eql("Feature");
 	});
+
+	it("should allow specific precisions", function () {
+		var marker = new L.Marker([10, 20]),
+		    polyline = new L.Polyline([[10, 20], [2, 5]]),
+		    layerGroup = new L.LayerGroup([marker, polyline]);
+		expect(layerGroup.toGeoJSON(3)).to.eql({
+			type: 'FeatureCollection',
+			features: [marker.toGeoJSON(3), polyline.toGeoJSON(3)]
+		});
+	});
 });

src/layer/GeoJSON.js

@@ -240,24 +240,25 @@ export function coordsToLatLngs(coords, levelsDeep, _coordsToLatLng) {
 	return latlngs;
 }
 
-// @function latLngToCoords(latlng: LatLng): Array
+// @function latLngToCoords(latlng: LatLng, precision?: Number): Array
 // Reverse of [`coordsToLatLng`](#geojson-coordstolatlng)
-export function latLngToCoords(latlng) {
+export function latLngToCoords(latlng, precision) {
+	precision = typeof precision === 'number' ? precision : 6;
 	return latlng.alt !== undefined ?
-			[latlng.lng, latlng.lat, latlng.alt] :
+			[Util.formatNum(latlng.lng, precision), Util.formatNum(latlng.lat, precision), Util.formatNum(latlng.alt, precision)] :
-			[latlng.lng, latlng.lat];
+			[Util.formatNum(latlng.lng, precision), Util.formatNum(latlng.lat, precision)];
 }
 
 // @function latLngsToCoords(latlngs: Array, levelsDeep?: Number, closed?: Boolean): Array
 // Reverse of [`coordsToLatLngs`](#geojson-coordstolatlngs)
 // `closed` determines whether the first point should be appended to the end of the array to close the feature, only used when `levelsDeep` is 0. False by default.
-export function latLngsToCoords(latlngs, levelsDeep, closed) {
+export function latLngsToCoords(latlngs, levelsDeep, closed, precision) {
 	var coords = [];
 
 	for (var i = 0, len = latlngs.length; i < len; i++) {
 		coords.push(levelsDeep ?
-			latLngsToCoords(latlngs[i], levelsDeep - 1, closed) :
+			latLngsToCoords(latlngs[i], levelsDeep - 1, closed, precision) :
-			latLngToCoords(latlngs[i]));
+			latLngToCoords(latlngs[i], precision));
 	}
 
 	if (!levelsDeep && closed) {
@@ -288,10 +289,10 @@ export function asFeature(geojson) {
 }
 
 var PointToGeoJSON = {
-	toGeoJSON: function () {
+	toGeoJSON: function (precision) {
 		return getFeature(this, {
 			type: 'Point',
-			coordinates: latLngToCoords(this.getLatLng())
+			coordinates: latLngToCoords(this.getLatLng(), precision)
 		});
 	}
 };
@@ -312,10 +313,10 @@ CircleMarker.include(PointToGeoJSON);
 // @method toGeoJSON(): Object
 // Returns a [`GeoJSON`](http://en.wikipedia.org/wiki/GeoJSON) representation of the polyline (as a GeoJSON `LineString` or `MultiLineString` Feature).
 Polyline.include({
-	toGeoJSON: function () {
+	toGeoJSON: function (precision) {
 		var multi = !LineUtil._flat(this._latlngs);
 
-		var coords = latLngsToCoords(this._latlngs, multi ? 1 : 0);
+		var coords = latLngsToCoords(this._latlngs, multi ? 1 : 0, false, precision);
 
 		return getFeature(this, {
 			type: (multi ? 'Multi' : '') + 'LineString',
@@ -328,11 +329,11 @@ Polyline.include({
 // @method toGeoJSON(): Object
 // Returns a [`GeoJSON`](http://en.wikipedia.org/wiki/GeoJSON) representation of the polygon (as a GeoJSON `Polygon` or `MultiPolygon` Feature).
 Polygon.include({
-	toGeoJSON: function () {
+	toGeoJSON: function (precision) {
 		var holes = !LineUtil._flat(this._latlngs),
 		    multi = holes && !LineUtil._flat(this._latlngs[0]);
 
-		var coords = latLngsToCoords(this._latlngs, multi ? 2 : holes ? 1 : 0, true);
+		var coords = latLngsToCoords(this._latlngs, multi ? 2 : holes ? 1 : 0, true, precision);
 
 		if (!holes) {
 			coords = [coords];
@@ -348,11 +349,11 @@ Polygon.include({
 
 // @namespace LayerGroup
 LayerGroup.include({
-	toMultiPoint: function () {
+	toMultiPoint: function (precision) {
 		var coords = [];
 
 		this.eachLayer(function (layer) {
-			coords.push(layer.toGeoJSON().geometry.coordinates);
+			coords.push(layer.toGeoJSON(precision).geometry.coordinates);
 		});
 
 		return getFeature(this, {
@@ -363,12 +364,12 @@ LayerGroup.include({
 
 	// @method toGeoJSON(): Object
 	// Returns a [`GeoJSON`](http://en.wikipedia.org/wiki/GeoJSON) representation of the layer group (as a GeoJSON `FeatureCollection`, `GeometryCollection`, or `MultiPoint`).
-	toGeoJSON: function () {
+	toGeoJSON: function (precision) {
 
 		var type = this.feature && this.feature.geometry && this.feature.geometry.type;
 
 		if (type === 'MultiPoint') {
-			return this.toMultiPoint();
+			return this.toMultiPoint(precision);
 		}
 
 		var isGeometryCollection = type === 'GeometryCollection',
@@ -376,7 +377,7 @@ LayerGroup.include({
 
 		this.eachLayer(function (layer) {
 			if (layer.toGeoJSON) {
-				var json = layer.toGeoJSON();
+				var json = layer.toGeoJSON(precision);
 				if (isGeometryCollection) {
 					jsons.push(json.geometry);
 				} else {