From e868c3291f18fc8c50d0587313cfb32b3cbbfaeb Mon Sep 17 00:00:00 2001
From: Mateusz Kwasniewski <kwasniewski.mateusz@gmail.com>
Date: Fri, 5 Apr 2024 15:34:08 +0200
Subject: [PATCH] feat: feature lifecycle metrics from event bus (#6789)

---
 .../feature-lifecycle-service.test.ts         |  9 +++++++--
 .../feature-lifecycle-service.ts              | 11 +++++++++--
 .../feature-lifecycle.e2e.test.ts             | 19 +++++++++++++++++--
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/lib/features/feature-lifecycle/feature-lifecycle-service.test.ts b/src/lib/features/feature-lifecycle/feature-lifecycle-service.test.ts
index 7ee3154b44..612952659a 100644
--- a/src/lib/features/feature-lifecycle/feature-lifecycle-service.test.ts
+++ b/src/lib/features/feature-lifecycle/feature-lifecycle-service.test.ts
@@ -7,20 +7,23 @@ import {
     type IUnleashConfig,
 } from '../../types';
 import { createFakeFeatureLifecycleService } from './createFeatureLifecycle';
+import EventEmitter from 'events';
 
 function ms(timeMs) {
     return new Promise((resolve) => setTimeout(resolve, timeMs));
 }
 
 test('can insert and read lifecycle stages', async () => {
+    const eventBus = new EventEmitter();
     const { featureLifecycleService, eventStore, environmentStore } =
         createFakeFeatureLifecycleService({
             flagResolver: { isEnabled: () => true },
+            eventBus,
         } as unknown as IUnleashConfig);
     const featureName = 'testFeature';
 
     async function emitMetricsEvent(environment: string) {
-        await eventStore.emit(CLIENT_METRICS, { featureName, environment });
+        await eventBus.emit(CLIENT_METRICS, { featureName, environment });
         await ms(1);
     }
 
@@ -68,9 +71,11 @@ test('can insert and read lifecycle stages', async () => {
 });
 
 test('ignores lifecycle state updates when flag disabled', async () => {
+    const eventBus = new EventEmitter();
     const { featureLifecycleService, eventStore, environmentStore } =
         createFakeFeatureLifecycleService({
             flagResolver: { isEnabled: () => false },
+            eventBus,
         } as unknown as IUnleashConfig);
     const featureName = 'testFeature';
 
@@ -82,7 +87,7 @@ test('ignores lifecycle state updates when flag disabled', async () => {
 
     await eventStore.emit(FEATURE_CREATED, { featureName });
     await eventStore.emit(FEATURE_COMPLETED, { featureName });
-    await eventStore.emit(CLIENT_METRICS, {
+    await eventBus.emit(CLIENT_METRICS, {
         featureName,
         environment: 'development',
     });
diff --git a/src/lib/features/feature-lifecycle/feature-lifecycle-service.ts b/src/lib/features/feature-lifecycle/feature-lifecycle-service.ts
index 54bc637675..41e433ef33 100644
--- a/src/lib/features/feature-lifecycle/feature-lifecycle-service.ts
+++ b/src/lib/features/feature-lifecycle/feature-lifecycle-service.ts
@@ -12,6 +12,7 @@ import type {
     FeatureLifecycleView,
     IFeatureLifecycleStore,
 } from './feature-lifecycle-store-type';
+import type EventEmitter from 'events';
 
 export class FeatureLifecycleService {
     private eventStore: IEventStore;
@@ -22,6 +23,8 @@ export class FeatureLifecycleService {
 
     private flagResolver: IFlagResolver;
 
+    private eventBus: EventEmitter;
+
     constructor(
         {
             eventStore,
@@ -32,12 +35,16 @@ export class FeatureLifecycleService {
             environmentStore: IEnvironmentStore;
             featureLifecycleStore: IFeatureLifecycleStore;
         },
-        { flagResolver }: Pick<IUnleashConfig, 'flagResolver'>,
+        {
+            flagResolver,
+            eventBus,
+        }: Pick<IUnleashConfig, 'flagResolver' | 'eventBus'>,
     ) {
         this.eventStore = eventStore;
         this.featureLifecycleStore = featureLifecycleStore;
         this.environmentStore = environmentStore;
         this.flagResolver = flagResolver;
+        this.eventBus = eventBus;
     }
 
     private async checkEnabled(fn: () => Promise<void>) {
@@ -53,7 +60,7 @@ export class FeatureLifecycleService {
                 this.featureInitialized(event.featureName),
             );
         });
-        this.eventStore.on(CLIENT_METRICS, async (event) => {
+        this.eventBus.on(CLIENT_METRICS, async (event) => {
             await this.checkEnabled(() =>
                 this.featureReceivedMetrics(
                     event.featureName,
diff --git a/src/lib/features/feature-lifecycle/feature-lifecycle.e2e.test.ts b/src/lib/features/feature-lifecycle/feature-lifecycle.e2e.test.ts
index eb275f1434..108c0e35ec 100644
--- a/src/lib/features/feature-lifecycle/feature-lifecycle.e2e.test.ts
+++ b/src/lib/features/feature-lifecycle/feature-lifecycle.e2e.test.ts
@@ -4,9 +4,15 @@ import {
     setupAppWithAuth,
 } from '../../../test/e2e/helpers/test-helper';
 import getLogger from '../../../test/fixtures/no-logger';
+import {
+    FEATURE_ARCHIVED,
+    FEATURE_CREATED,
+    type IEventStore,
+} from '../../types';
 
 let app: IUnleashTest;
 let db: ITestDb;
+let eventStore: IEventStore;
 
 beforeAll(async () => {
     db = await dbInit('feature_lifecycle', getLogger);
@@ -21,6 +27,7 @@ beforeAll(async () => {
         },
         db.rawDatabase,
     );
+    eventStore = db.stores.eventStore;
 
     await app.request
         .post(`/auth/demo/login`)
@@ -43,10 +50,18 @@ const getFeatureLifecycle = async (featureName: string, expectedCode = 200) => {
         .expect(expectedCode);
 };
 
+function ms(timeMs) {
+    return new Promise((resolve) => setTimeout(resolve, timeMs));
+}
+
 test('should return lifecycle stages', async () => {
-    await app.createFeature('my_feature_a');
+    await eventStore.emit(FEATURE_CREATED, { featureName: 'my_feature_a' });
+    await eventStore.emit(FEATURE_ARCHIVED, { featureName: 'my_feature_a' });
 
     const { body } = await getFeatureLifecycle('my_feature_a');
 
-    expect(body).toEqual([]);
+    expect(body).toEqual([
+        { stage: 'initial', enteredStageAt: expect.any(String) },
+        { stage: 'archived', enteredStageAt: expect.any(String) },
+    ]);
 });