1 files changed, 45 insertions, 11 deletions

diff --git a/app/geometry.js b/app/geometry.js
index 0952bbb..37bb34f 100644
--- a/app/geometry.js
+++ b/app/geometry.js
@@ -65,6 +65,17 @@ export class Bounds {
 }
 
 /**
+ * @enum {string}
+ */
+export const GeometryType = {
+	linestring: "Line",
+	multilinestring: "MultiLineString",
+	multipolygon: "MultiPolygon",
+	point: "Point",
+	polygon: "Polygon",
+};
+
+/**
  * @typedef {[number, number]} Coordinate - [longitude, latitude] in decimal degrees
  */
 
@@ -133,6 +144,24 @@ export class Geometry {
 
 	/**
 	 * Deserialize geometry from GeoJSON
+	 * @param {Point|LineString|Polygon|MultiLineString} geometry
+	 */
+	static toEnum(geometry) {
+		if (geometry instanceof Point) {
+			return GeometryType.point;
+		} else if (geometry instanceof LineString) {
+			return GeometryType.linestring;
+		} else if (geometry instanceof MultiLineString) {
+			return GeometryType.multilinestring;
+		} else if (geometry instanceof Polygon) {
+			return GeometryType.polygon;
+		} else {
+			throw new Error(`Invalid GeoJSON object: missing required 'type' property`);
+		}
+	}
+
+	/**
+	 * Deserialize geometry from GeoJSON
 	 * @param {{type: string, coordinates?: any, [key: string]: any}} geojson
 	 * @returns {Point|LineString|Polygon|MultiLineString}
 	 */
@@ -161,13 +190,11 @@ export class Geometry {
 	static bounds(geometry) {
 		if (geometry instanceof Point) {
 			return new Bounds(geometry.lng, geometry.lat, geometry.lng, geometry.lat);
-		}
-
-		if (geometry instanceof LineString) {
+		} else if (geometry instanceof LineString) {
 			return Geometry.calculateBoundsFromCoords(geometry.coordinates);
-		}
-
-		if (geometry instanceof Polygon) {
+		} else if (geometry instanceof MultiLineString) {
+			return Geometry.calculateBoundsFromCoords(geometry.coordinates);
+		} else if (geometry instanceof Polygon) {
 			return Geometry.calculateBoundsFromCoords(geometry.rings[0]);
 		}
 		throw new Error(`Unsupported geometry type: ${geometry}`);
@@ -1028,12 +1055,14 @@ export class Polygon extends Geometry {
 
 export class Feature {
 	/**
-	 * @param {Geometry} geometry - Feature geometry
-	 * @param {Object} [properties={}] - Feature properties
-	 * @param {string|number} [id] - Feature ID
+	 * @param {Geometry} geometry
+	 * @param {GeometryType} type
+	 * @param {Object} [properties={}]
+	 * @param {string|number} [id]
 	 */
-	constructor(geometry, properties = {}, id = "") {
+	constructor(geometry, type, properties = {}, id = "") {
 		this.geometry = geometry;
+		this.type = type;
 		this.properties = properties;
 		this.id = id;
 	}
@@ -1062,7 +1091,12 @@ export class Feature {
 		const geometry = Geometry.fromGeoJSON(geojson.geometry);
 		if (!geometry) return null;
 
-		return new Feature(geometry, geojson.properties ?? {}, geojson.id ?? "");
+		return new Feature(
+			geometry,
+			Geometry.toEnum(geometry),
+			geojson.properties ?? {},
+			geojson.id ?? "",
+		);
 	}
 }