From e7b757d7e109dd267d96c90e1224cf3eca4a46a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nuno=20G=C3=B3is?= <github@nunogois.com>
Date: Fri, 29 Aug 2025 10:20:43 +0100
Subject: [PATCH] chore: unknown flags should not include flags that exist in
 Unleash (#10568)

https://linear.app/unleash/issue/2-3825/fetching-unknown-flags-should-not-include-flags-that-currently-exist

Fetching unknown flags should not include flags that currently exist in
Unleash.

This is especially noticeable if you create a flag with an unknown
flag's name, since it won't go away from the list right away.
---
 .../unknown-flags/unknown-flags-store.ts      |  24 +--
 .../unknown-flags/unknown-flags.e2e.test.ts   | 137 ++++++++++++++++++
 2 files changed, 152 insertions(+), 9 deletions(-)

diff --git a/src/lib/features/metrics/unknown-flags/unknown-flags-store.ts b/src/lib/features/metrics/unknown-flags/unknown-flags-store.ts
index f665f75a3d..9ac4d8098f 100644
--- a/src/lib/features/metrics/unknown-flags/unknown-flags-store.ts
+++ b/src/lib/features/metrics/unknown-flags/unknown-flags-store.ts
@@ -66,18 +66,24 @@ export class UnknownFlagsStore implements IUnknownFlagsStore {
     }
 
     async getAll({ limit, orderBy }: QueryParams = {}): Promise<UnknownFlag[]> {
-        let query = this.db(`${TABLE} AS uf`).select(
-            'uf.name',
-            'uf.app_name',
-            'uf.seen_at',
-            'uf.environment',
-            this.db.raw(
-                `(SELECT MAX(e.created_at)
+        let query = this.db(`${TABLE} AS uf`)
+            .select(
+                'uf.name',
+                'uf.app_name',
+                'uf.seen_at',
+                'uf.environment',
+                this.db.raw(
+                    `(SELECT MAX(e.created_at)
                 FROM ${TABLE_EVENTS} AS e
                 WHERE e.feature_name = uf.name)
                 AS last_event_at`,
-            ),
-        );
+                ),
+            )
+            .whereNotExists(
+                this.db('features as f')
+                    .select(this.db.raw('1'))
+                    .whereRaw('f.name = uf.name'),
+            );
 
         if (orderBy) {
             query = query.orderBy(orderBy);
diff --git a/src/lib/features/metrics/unknown-flags/unknown-flags.e2e.test.ts b/src/lib/features/metrics/unknown-flags/unknown-flags.e2e.test.ts
index 898356a3dd..be89d2811d 100644
--- a/src/lib/features/metrics/unknown-flags/unknown-flags.e2e.test.ts
+++ b/src/lib/features/metrics/unknown-flags/unknown-flags.e2e.test.ts
@@ -182,3 +182,140 @@ describe('should register unknown flags', () => {
         );
     });
 });
+
+describe('should fetch unknown flags', () => {
+    test('returns empty list by default', async () => {
+        const res = await request
+            .get('/api/admin/metrics/unknown-flags')
+            .expect(200)
+            .expect('Content-Type', /json/);
+
+        expect(res.body).toMatchObject({
+            unknownFlags: [],
+        });
+    });
+
+    test('returns list of unknown flags', async () => {
+        const unknownFlag: BulkRegistrationSchema = {
+            appName: 'demo',
+            instanceId: '1',
+            environment: 'development',
+            sdkVersion: 'unleash-client-js:1.0.0',
+            sdkType: 'frontend',
+        };
+
+        await request
+            .post('/api/client/metrics/bulk')
+            .send({
+                applications: [unknownFlag],
+                metrics: [
+                    {
+                        featureName: 'unknown_flag_1',
+                        environment: 'development',
+                        appName: 'demo',
+                        timestamp: startOfHour(new Date()),
+                        yes: 1337,
+                        no: 0,
+                        variants: {},
+                    },
+                    {
+                        featureName: 'unknown_flag_2',
+                        environment: 'development',
+                        appName: 'demo',
+                        timestamp: startOfHour(new Date()),
+                        yes: 200,
+                        no: 100,
+                        variants: {},
+                    },
+                ],
+            })
+            .expect(202);
+
+        await services.unknownFlagsService.flush();
+
+        const res = await request
+            .get('/api/admin/metrics/unknown-flags')
+            .expect(200)
+            .expect('Content-Type', /json/);
+
+        expect(res.body.unknownFlags).toHaveLength(2);
+        expect(res.body.unknownFlags).toEqual([
+            expect.objectContaining({
+                name: 'unknown_flag_1',
+                environment: 'development',
+                appName: 'demo',
+                lastEventAt: null,
+            }),
+            expect.objectContaining({
+                name: 'unknown_flag_2',
+                environment: 'development',
+                appName: 'demo',
+                lastEventAt: null,
+            }),
+        ]);
+    });
+
+    test('does not include flags that have since been created in Unleash', async () => {
+        const unknownFlag: BulkRegistrationSchema = {
+            appName: 'demo',
+            instanceId: '1',
+            environment: 'development',
+            sdkVersion: 'unleash-client-js:1.0.0',
+            sdkType: 'frontend',
+        };
+
+        await request
+            .post('/api/client/metrics/bulk')
+            .send({
+                applications: [unknownFlag],
+                metrics: [
+                    {
+                        featureName: 'flag_that_will_be_created',
+                        environment: 'development',
+                        appName: 'demo',
+                        timestamp: startOfHour(new Date()),
+                        yes: 1337,
+                        no: 0,
+                        variants: {},
+                    },
+                    {
+                        featureName: 'unknown_flag_2',
+                        environment: 'development',
+                        appName: 'demo',
+                        timestamp: startOfHour(new Date()),
+                        yes: 200,
+                        no: 100,
+                        variants: {},
+                    },
+                ],
+            })
+            .expect(202);
+
+        await services.unknownFlagsService.flush();
+
+        await request
+            .post('/api/admin/projects/default/features')
+            .send({
+                name: 'flag_that_will_be_created',
+                description: '',
+                type: 'release',
+                impressionData: false,
+            })
+            .expect(201);
+
+        const res = await request
+            .get('/api/admin/metrics/unknown-flags')
+            .expect(200)
+            .expect('Content-Type', /json/);
+
+        expect(res.body.unknownFlags).toHaveLength(1);
+        expect(res.body.unknownFlags).toEqual([
+            expect.objectContaining({
+                name: 'unknown_flag_2',
+                environment: 'development',
+                appName: 'demo',
+                lastEventAt: null,
+            }),
+        ]);
+    });
+});