fix: add cache decorator when getting ip address

lib/services/ip-service.ts

@@ -1,9 +1,12 @@
+import { cache } from "../common/decorators";
+
 export class IPService implements IIPService {
 	private static GET_IP_TIMEOUT = 1000;
 	constructor(private $config: IConfiguration,
 		private $httpClient: Server.IHttpClient,
 		private $logger: ILogger) { }
 
+	@cache()
 	public async getCurrentIPv4Address(): Promise<string> {
 		const ipAddress = await this.getIPAddressFromServiceReturningJSONWithIPProperty(this.$config.WHOAMI_URL_ENDPOINT) ||
 			await this.getIPAddressFromServiceReturningJSONWithIPProperty("https://api.myip.com") ||

test/services/ip-service.ts

@@ -135,5 +135,25 @@ describe("ipService", () => {
 			assert.isTrue(logger.traceOutput.indexOf(errMsgForMyipCom) !== -1, `Trace output\n'${logger.traceOutput}'\ndoes not contain expected message:\n${errMsgForMyipCom}`);
 			assert.isTrue(logger.traceOutput.indexOf(errMsgForIpifyOrg) !== -1, `Trace output\n'${logger.traceOutput}'\ndoes not contain expected message:\n${errMsgForMyipCom}`);
 		});
+
+		it("is called only once per process", async () => {
+			const testInjector = createTestInjector();
+			const httpClient = testInjector.resolve<Server.IHttpClient>("httpClient");
+			let httpRequestCounter = 0;
+			httpClient.httpRequest = async (options: any, proxySettings?: IProxySettings): Promise<Server.IResponse> => {
+				httpRequestCounter++;
+				return <any>{ body: JSON.stringify({ ip }) };
+			};
+
+			const ipService = testInjector.resolve<IIPService>("ipService");
+
+			const ipAddress = await ipService.getCurrentIPv4Address();
+			assert.equal(httpRequestCounter, 1);
+			assert.equal(ipAddress, ip);
+
+			const ipAddress2 = await ipService.getCurrentIPv4Address();
+			assert.equal(httpRequestCounter, 1);
+			assert.equal(ipAddress2, ip);
+		});
 	});
 });