improve tagging

Author: haljac

src/ExpressBridge.ts

@@ -41,24 +41,8 @@ export class ExpressBridge {
       console.log('Telemetry enabled: ', !!process.env.EB_TELEMETRY);
       if (process.env.EB_TELEMETRY && this.options.telemetry) {
         console.log('Telemetry enabled, setting trace tag on event.');
-        if ('body' in incomingEvent) {
-          incomingEvent.body =
-            typeof incomingEvent.body === 'string'
-              ? JSON.parse(incomingEvent.body)
-              : incomingEvent.body;
-          incomingEvent.body.eb_event_id =
-            incomingEvent.body?.eb_event_id || v4();
-        } else if (incomingEvent.Records) {
-          for (const record of incomingEvent.Records) {
-            record.eb_event_id = record.eb_event_id || v4();
-          }
-        } else {
-          incomingEvent.eb_event_id = incomingEvent.eb_event_id || v4();
-        }
-        this.telemetry = new Telemetry(
-          incomingEvent.body.eb_event_id,
-          this.options.telemetry
-        );
+        this.telemetry = new Telemetry(this.options.telemetry);
+        const tag = this.telemetry.tagEvent(incomingEvent);
       }
 
       await this.telemetry?.beacon('EB-PROCESS', {
@@ -133,11 +117,7 @@ export class ExpressBridge {
   public post(...handlers: handlerType[]): void {
     this.postHandlers.push(...handlers);
   }
-
-  public getTelemetryId() {
-    return this.telemetry.eb_event_id;
-  }
-
+  /*  */
   private match(
     incomingEvent: Record<string, any>
   ): EventPattern<typeof incomingEvent>[] {

src/Telemetry.ts

@@ -7,10 +7,9 @@ export type TelemetryConfig = Partial<AxiosRequestConfig> & {
 };
 
 export class Telemetry {
-  constructor(
-    public eb_event_id: string,
-    private requestConfig: TelemetryConfig
-  ) {}
+  private eb_event_id: string;
+
+  constructor(private requestConfig: TelemetryConfig) {}
 
   public async beacon(
     tag: string,
@@ -32,19 +31,25 @@ export class Telemetry {
     }
   }
 
-  public tagEvent(event: Record<string, any>): Record<string, any> {
+  public tagEvent(event: Record<string, any>): string {
     const { body, detail, Records } = event;
     let payload = body ?? detail ?? Records;
 
+    console.log('Tagging payload: ', payload);
+
     const tag = v4();
     if (Array.isArray(payload)) {
       for (const record of payload) {
         record.eb_event_id = record.eb_event_id || tag;
       }
+    } else if (!payload) {
+      event.eb_event_id = event.eb_event_id || tag;
     } else {
       payload = typeof payload === 'string' ? JSON.parse(payload) : payload;
       payload.eb_event_id = payload.eb_event_id || tag;
     }
-    return event;
+
+    this.eb_event_id = tag;
+    return tag;
   }
 }

src/tests/expressBridge.data.ts

@@ -73,4 +73,23 @@ export default {
     },
     stageVariables: {},
   },
+  eventBridgeMessage: {
+    version: '0',
+    id: '301a585b-1fc4-00bb-f5b2-a4f887684942',
+    'detail-type': 'message',
+    source: 'acme.payments',
+    account: '018345072091',
+    time: '2022-01-29T05:57:47Z',
+    region: 'us-east-1',
+    resources: [],
+    detail: {
+      id: 1234,
+      userId: 'user@example.com',
+      price: 10,
+      serviceTier: 'premium',
+      address: '2965 S Sierra Heights, Mesa, AZ 85212',
+      createdAt: 1000001231234,
+      eb_event_id: '20e1b1ba-05da-40b9-aa98-6d81eca40041',
+    },
+  },
 };

src/tests/expressBridge.test.ts

@@ -66,39 +66,3 @@ describe('Test ExpressBridge', () => {
     //expect(true).toBe(true);
   });
 });
-
-describe('test event id persistence between services', () => {
-  beforeEach(() => {
-    jest.clearAllMocks();
-  });
-
-  test('should persist eb_event_id between services', async () => {
-    // expressBridge modifies the event by 'tagging' it with an
-    // id used for telemetry
-    // this is where a REAL wrapper object would be useful later --
-    // to track related event messages
-    process.env.EB_TELEMETRY = 'true';
-    const message = { ...messages.httpMessage };
-
-    const ordersBridge = new ExpressBridge({
-      alwaysRunHooks: true,
-      telemetry: {
-        serviceName: 'orders',
-      },
-    });
-    ordersBridge.process(message);
-    const ordersEventId = message.body.eb_event_id;
-    expect(ordersEventId).toBeTruthy();
-
-    const paymentsBridge = new ExpressBridge({
-      alwaysRunHooks: true,
-      telemetry: {
-        serviceName: 'payments',
-      },
-    });
-    paymentsBridge.process(message);
-    const paymentsEventId = message.body.eb_event_id;
-
-    expect(ordersEventId).toEqual(paymentsEventId);
-  });
-});

src/tests/telemetry.test.ts

@@ -1,5 +1,4 @@
 import axios from 'axios';
-import { v4 } from 'uuid';
 import { Telemetry } from '../Telemetry';
 
 jest.mock('axios', () => ({
@@ -17,8 +16,7 @@ describe('test telemetry functionality', () => {
   test('should exercise telemetry functionality under correct conditions', async () => {
     expect(process.env.EB_TELEMETRY).toBe('true');
 
-    const eventId = v4();
-    const telemetry = new Telemetry(eventId, {
+    const telemetry = new Telemetry({
       url: 'foo.com/telemetry',
       method: 'post',
       headers: {
@@ -27,8 +25,6 @@ describe('test telemetry functionality', () => {
       serviceName: 'orders',
     });
 
-    expect(telemetry.eb_event_id).toBeDefined();
-
     const message = {
       name: 'Johnny Appleseed',
       item: 'Moleskine Notebooks',
@@ -42,14 +38,15 @@ describe('test telemetry functionality', () => {
       },
     };
 
+    const tag = telemetry.tagEvent(message);
     telemetry.beacon('EB-TEST', message);
 
     expect(axios).toHaveBeenCalledWith(
       expect.objectContaining({
         data: {
           tag: 'EB-TEST',
           message,
-          eb_event_id: eventId,
+          eb_event_id: tag,
           serviceName: 'orders',
         },
       })