From cad4547b29723c59b51f2eaade963a16d4d541dd Mon Sep 17 00:00:00 2001
From: Jaanus Sellin <sellinjaanus@gmail.com>
Date: Tue, 12 Sep 2023 11:43:01 +0300
Subject: [PATCH] fix: last seen environment remove duplicate entries (#4663)

---
 .../client-metrics/last-seen-service.test.ts  | 61 +++++++++++++++++++
 .../client-metrics/last-seen-service.ts       | 21 ++++---
 2 files changed, 75 insertions(+), 7 deletions(-)
 create mode 100644 src/lib/services/client-metrics/last-seen-service.test.ts

diff --git a/src/lib/services/client-metrics/last-seen-service.test.ts b/src/lib/services/client-metrics/last-seen-service.test.ts
new file mode 100644
index 000000000000..90f181772a7b
--- /dev/null
+++ b/src/lib/services/client-metrics/last-seen-service.test.ts
@@ -0,0 +1,61 @@
+import createStores from '../../../test/fixtures/store';
+import EventEmitter from 'events';
+import getLogger from '../../../test/fixtures/no-logger';
+import { IUnleashConfig } from '../../types';
+import { LastSeenService } from './last-seen-service';
+
+function initLastSeenService(flagEnabled = true) {
+    const stores = createStores();
+
+    const eventBus = new EventEmitter();
+    eventBus.emit = jest.fn();
+
+    const config = {
+        eventBus,
+        getLogger,
+        flagResolver: {
+            isEnabled: () => {
+                return flagEnabled;
+            },
+        },
+    } as unknown as IUnleashConfig;
+
+    const lastSeenService = new LastSeenService(stores, config);
+
+    return { lastSeenService, featureToggleStore: stores.featureToggleStore };
+}
+
+test('should not add duplicates per feature/environment', async () => {
+    const { lastSeenService, featureToggleStore } = initLastSeenService();
+
+    lastSeenService.updateLastSeen([
+        {
+            featureName: 'myFeature',
+            environment: 'development',
+            yes: 1,
+            no: 0,
+            appName: 'test',
+            timestamp: new Date(),
+        },
+    ]);
+
+    lastSeenService.updateLastSeen([
+        {
+            featureName: 'myFeature',
+            environment: 'development',
+            yes: 1,
+            no: 0,
+            appName: 'test',
+            timestamp: new Date(),
+        },
+    ]);
+    featureToggleStore.setLastSeen = jest.fn();
+    await lastSeenService.store();
+
+    expect(featureToggleStore.setLastSeen).toHaveBeenCalledWith([
+        {
+            environment: 'development',
+            featureName: 'myFeature',
+        },
+    ]);
+});
diff --git a/src/lib/services/client-metrics/last-seen-service.ts b/src/lib/services/client-metrics/last-seen-service.ts
index 640a87f57aab..c4d9564f4993 100644
--- a/src/lib/services/client-metrics/last-seen-service.ts
+++ b/src/lib/services/client-metrics/last-seen-service.ts
@@ -13,7 +13,7 @@ export type LastSeenInput = {
 export class LastSeenService {
     private timers: NodeJS.Timeout[] = [];
 
-    private lastSeenToggles: Set<LastSeenInput> = new Set();
+    private lastSeenToggles: Map<String, LastSeenInput> = new Map();
 
     private logger: Logger;
 
@@ -37,8 +37,8 @@ export class LastSeenService {
     async store(): Promise<number> {
         const count = this.lastSeenToggles.size;
         if (count > 0) {
-            const lastSeenToggles = [...this.lastSeenToggles];
-            this.lastSeenToggles = new Set();
+            const lastSeenToggles = Array.from(this.lastSeenToggles.values());
+            this.lastSeenToggles = new Map<String, LastSeenInput>();
             this.logger.debug(
                 `Updating last seen for ${lastSeenToggles.length} toggles`,
             );
@@ -49,15 +49,22 @@ export class LastSeenService {
 
     updateLastSeen(clientMetrics: IClientMetricsEnv[]): void {
         clientMetrics
+            .filter(
+                (clientMetric) =>
+                    !this.lastSeenToggles.has(
+                        `${clientMetric.featureName}:${clientMetric.environment}`,
+                    ),
+            )
             .filter(
                 (clientMetric) => clientMetric.yes > 0 || clientMetric.no > 0,
             )
-            .forEach((clientMetric) =>
-                this.lastSeenToggles.add({
+            .forEach((clientMetric) => {
+                const key = `${clientMetric.featureName}:${clientMetric.environment}`;
+                this.lastSeenToggles.set(key, {
                     featureName: clientMetric.featureName,
                     environment: clientMetric.environment,
-                }),
-            );
+                });
+            });
     }
 
     destroy(): void {