Add GeometryUtil functions to leaflet-draw (#14755)

* Add GeometryUtil functions to leaflet-draw

Add two functions in the GeometryUtil namespace of leaflet-draw

* Remove illegal whitespaces

* Add GeometryUtil function calls to tests

Validate that the function declarations are valid by adding calls of
geodesicArea() and readableArea() to the tests.
Remove a whitespace that the linter complained about.

leaflet-draw/index.d.ts

@@ -349,4 +349,17 @@ declare namespace L {
 			handler: string;
 		}
 	}
+
+	namespace GeometryUtil {
+
+		/**
+		 * Returns the area of a polygon drawn with leaflet.draw
+		 */
+		export function geodesicArea(coordinates: L.LatLngLiteral[]): number;
+
+		/**
+		 * Returns a readable area string in yards or metric
+		 */
+		export function readableArea(area: number, isMetric: boolean): string;
+	}
 }

leaflet-draw/leaflet-draw-tests.ts

@@ -42,3 +42,7 @@ map.on('draw:created', (e: any) => {
 
     drawnItems.addLayer(layer);
 });
+
+let examplePolygon: L.LatLngLiteral[] = [{lng: 0, lat: 0}, {lng: 10, lat: 0}, {lng: 10, lat: 10}, {lng: 0, lat: 10}, {lng: 0, lat: 0}];
+let examplePolygonArea: number = L.GeometryUtil.geodesicArea(examplePolygon);
+L.GeometryUtil.readableArea(examplePolygonArea, true);