added RequestError error with its test

src/error.ts

@@ -0,0 +1,10 @@
+export class RequestError extends Error {
+
+    public code: number;
+
+    constructor(msg: string, code: number) {
+        super(msg);
+
+        this.code = code;
+    }
+}

src/service.ts

@@ -1,4 +1,5 @@
 import Adaptor from "./adaptors/adaptor";
+import { RequestError } from "./error";
 import { Request, Response } from "./messages";
 import { RouteSubscribeTypeFn } from "./types";
 
@@ -35,10 +36,19 @@ export default class Service {
 
         try {
             const rawRes = await this.adaptors[adaptor].request(`${req.service}.${req.subject}`, rawReq);
+            const res: Response<U> = JSON.parse(rawRes);
 
-            return JSON.parse(rawRes);
+            if(res.statusCode < 200 || res.statusCode >= 599) {
+                throw new RequestError("error while request", res.statusCode);
+            }
+
+            return res;
         } catch(err) {
-            return { statusCode: 500 }
+            if(err instanceof RequestError) {
+                throw err;
+            } else {
+                throw new RequestError("unexpected error", 500);
+            }
         }    
     }
 

tests/lib.test.ts

@@ -1,15 +1,15 @@
 import NatsAdaptor from "../src/adaptors/nats";
+import { RequestError } from "../src/error";
 import { Message } from "../src/messages";
 import Service from "../src/service";
 
 let srv!: Service;
 
+const natsServer = '127.0.0.1:4222';
 const serviceName = "test-service";
 const adaptorName = "nats";
 const subject = "test";
 
-const dataExpected = "hello world";
-const statusCodeExpected = 200;
 
 beforeEach(() => {
     srv = new Service(serviceName);
@@ -19,8 +19,11 @@ afterEach(async () => {
     await srv.stop();
 });
 
-test('nats adaptor', async () => {
+test('nats adaptor success', async () => {
-    srv.addAdaptor(adaptorName, new NatsAdaptor({ servers: ['127.0.0.1:4222'] }));
+    const dataExpected = "hello success";
+    const statusCodeExpected = 200;
+
+    srv.addAdaptor(adaptorName, new NatsAdaptor({ servers: [natsServer] }));
     srv.subscribe(adaptorName, subject, async (msg: Message<string>) => {
         return {data: msg.data, statusCode: statusCodeExpected};
     });
@@ -33,3 +36,16 @@ test('nats adaptor', async () => {
     expect(res.statusCode).toBe(statusCodeExpected);
 });
 
+test('nats adaptor error', async () => {
+    const dataExpected = "hello error";
+    const statusCodeExpected = 500;
+
+    srv.addAdaptor(adaptorName, new NatsAdaptor({ servers: [natsServer] }));
+    srv.subscribe(adaptorName, subject, async (msg: Message<string>) => {
+        return {data: msg.data, statusCode: statusCodeExpected};
+    });
+
+    await srv.listen();
+    expect(srv.request(adaptorName, {service: serviceName, subject: subject, data: dataExpected})).rejects.toThrow(RequestError);
+});
+