fix: Counting distinct results for entity facets in search table

Signed-off-by: Stuart Said <stuartman9@hotmail.co.uk>

.changeset/cold-coats-show.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+Fix for duplicate search results in entity-facets API call

plugins/catalog-backend/src/service/DefaultEntitiesCatalog.test.ts

@@ -2359,6 +2359,52 @@ describe('DefaultEntitiesCatalog', () => {
         });
       },
     );
+
+    it.each(databases.eachSupportedId())(
+      'works when the entity is duplicated in search results, %p',
+      async databaseId => {
+        await createDatabase(databaseId);
+
+        await addEntityToSearch({
+          apiVersion: 'a',
+          kind: 'k',
+          metadata: {
+            name: 'one',
+            uid: 'uid-a',
+          },
+          spec: {},
+        });
+
+        // Manually insert a duplicate search entry, this shouldn't happen but does in reality
+        await knex<DbSearchRow>('search').insert([
+          {
+            entity_id: 'uid-a',
+            key: 'metadata.name',
+            value: 'one',
+            original_value: 'one',
+          },
+        ]);
+
+        const catalog = new DefaultEntitiesCatalog({
+          database: knex,
+          logger: mockServices.logger.mock(),
+          stitcher,
+        });
+
+        await expect(
+          catalog.facets({
+            facets: ['metadata.name'],
+            credentials: mockCredentials.none(),
+          }),
+        ).resolves.toEqual({
+          facets: {
+            'metadata.name': expect.arrayContaining([
+              { value: 'one', count: 1 },
+            ]),
+          },
+        });
+      },
+    );
   });
 });
 

plugins/catalog-backend/src/service/DefaultEntitiesCatalog.ts

@@ -683,7 +683,7 @@ export class DefaultEntitiesCatalog implements EntitiesCatalog {
       .select({
         facet: 'search.key',
         value: 'search.original_value',
-        count: this.database.raw('count(*)'),
+        count: this.database.raw('count(DISTINCT search.entity_id)'),
       })
       .groupBy(['search.key', 'search.original_value']);