Fix existing followed assets not getting listed after search Reindexing

openmetadata-service/src/main/java/org/openmetadata/service/jdbi3/EntityRepository.java

@@ -409,6 +409,7 @@ protected EntityRepository(
 
     fieldSupportMap.put(FIELD_TAGS, Pair.of(supportsTags, this::fetchAndSetTags));
     fieldSupportMap.put(FIELD_OWNERS, Pair.of(supportsOwners, this::fetchAndSetOwners));
+    fieldSupportMap.put(FIELD_FOLLOWERS, Pair.of(supportsFollower, this::fetchAndSetFollowers));
     fieldSupportMap.put(FIELD_DOMAINS, Pair.of(supportsDomains, this::fetchAndSetDomains));
     fieldSupportMap.put(FIELD_REVIEWERS, Pair.of(supportsReviewers, this::fetchAndSetReviewers));
     fieldSupportMap.put(FIELD_EXTENSION, Pair.of(supportsExtension, this::fetchAndSetExtension));
@@ -5018,6 +5019,16 @@ private void fetchAndSetOwners(List<T> entities, Fields fields) {
     }
   }
 
+  private void fetchAndSetFollowers(List<T> entities, Fields fields) {
+    if (!fields.contains(FIELD_FOLLOWERS) || !supportsFollower) {
+      return;
+    }
+    Map<UUID, List<EntityReference>> followersMap = batchFetchFollowers(entities);
+    for (T entity : entities) {
+      entity.setFollowers(followersMap.getOrDefault(entity.getId(), Collections.emptyList()));
+    }
+  }
+
   private void fetchAndSetTags(List<T> entities, Fields fields) {
     if (!fields.contains(FIELD_TAGS) || !supportsTags) {
       return;
@@ -5143,6 +5154,31 @@ private Map<UUID, List<EntityReference>> batchFetchOwners(List<T> entities) {
     return ownersMap;
   }
 
+  private Map<UUID, List<EntityReference>> batchFetchFollowers(List<T> entities) {
+    if (entities.isEmpty()) {
+      return Collections.emptyMap();
+    }
+
+    List<CollectionDAO.EntityRelationshipObject> followerRecords =
+        daoCollection
+            .relationshipDAO()
+            .findFromBatch(
+                entityListToStrings(entities), Relationship.FOLLOWS.ordinal(), Include.ALL);
+
+    Map<UUID, List<EntityReference>> followersMap = new HashMap<>();
+    for (CollectionDAO.EntityRelationshipObject record : followerRecords) {
+      UUID entityId = UUID.fromString(record.getToId());
+      followersMap
+          .computeIfAbsent(entityId, k -> new ArrayList<>())
+          .add(
+              new EntityReference()
+                  .withId(UUID.fromString(record.getFromId()))
+                  .withType(record.getFromEntity()));
+    }
+
+    return followersMap;
+  }
+
   /**
    * Creates a unique key for a TagLabel combining TagFQN and Source for fast Set-based lookups.
    * This replaces O(n) stream().anyMatch() operations with O(1) Set.contains() operations.

openmetadata-service/src/test/java/org/openmetadata/service/resources/EntityResourceTest.java

@@ -899,14 +899,36 @@ void test_fieldFetchersEfficiency(TestInfo test) throws HttpResponseException {
         }
 
         if (fields.contains("followers") && supportsFollowers) {
-          // Note: followers might be null if no followers exist, which is expected
-          List<?> bulkFollowers = (List<?>) getField(entity, "followers");
-          List<?> individualFollowers = (List<?>) getField(individualEntity, "followers");
+          // Get the actual followers from both bulk and individual loading
+          List<EntityReference> bulkFollowers = entity.getFollowers();
+          List<EntityReference> individualFollowers = individualEntity.getFollowers();
+
+          // The test should verify that followers are actually fetched and populated
+          // Previously this might have passed because both were null/empty due to missing field
+          // support
           assertEquals(
               listOrEmpty(bulkFollowers).size(),
               listOrEmpty(individualFollowers).size(),
               "Followers field should be consistently loaded in bulk operations for fields: "
                   + fields);
+
+          // Add verification that if followers exist, they have proper entity references
+          if (!listOrEmpty(bulkFollowers).isEmpty()) {
+            for (EntityReference follower : bulkFollowers) {
+              assertNotNull(follower.getId(), "Follower should have valid ID");
+              assertNotNull(follower.getName(), "Follower should have valid name");
+              assertNotNull(follower.getType(), "Follower should have valid type");
+            }
+          }
+
+          // Verify that the followers data matches between bulk and individual fetch
+          if (!listOrEmpty(bulkFollowers).isEmpty()
+              && !listOrEmpty(individualFollowers).isEmpty()) {
+            assertEquals(
+                bulkFollowers,
+                individualFollowers,
+                "Followers data should be identical between bulk and individual loading");
+          }
         }
       }