Add Google Maps geocoder

routes/geocoders/GoogleMaps.ts

@@ -0,0 +1,35 @@
+import { GeoCoordinates } from "../../types";
+import { CodedError, ErrorCode } from "../../errors";
+import { httpJSONRequest } from "../weather";
+import { Geocoder } from "./Geocoder";
+
+export default class GoogleMaps extends Geocoder {
+	private readonly API_KEY: string;
+
+	public constructor() {
+		super();
+		this.API_KEY = process.env.GOOGLE_MAPS_API_KEY;
+		if ( !this.API_KEY ) {
+			throw "GOOGLE_MAPS_API_KEY environment variable is not defined.";
+		}
+	}
+
+	public async geocodeLocation( location: string ): Promise<GeoCoordinates> {
+		// Generate URL for Google Maps geocoding request
+		const url = `https://maps.googleapis.com/maps/api/geocode/json?key=${ this.API_KEY }&address=${ encodeURIComponent( location ) }`;
+
+		let data;
+		try {
+			data = await httpJSONRequest( url );
+		} catch ( err ) {
+			// If the request fails, indicate no data was found.
+			throw new CodedError( ErrorCode.LocationServiceApiError );
+		}
+
+		if ( !data.results.length ) {
+			throw new CodedError( ErrorCode.NoLocationFound );
+		}
+
+		return [ data.results[ 0 ].geometry.location.lat, data.results[ 0 ].geometry.location.lng ];
+	}
+}