Remove remaining N+1 queries in merge requests API with emojis and labels

Closes #34159

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/gitlab/issuable_metadata.rb b/lib/gitlab/issuable_metadata.rb
new file mode 100644
index 00000000000..977c05910d3
--- /dev/null
+++ b/lib/gitlab/issuable_metadata.rb
@@ -0,0 +1,36 @@
+module Gitlab
+  module IssuableMetadata
+    def issuable_meta_data(issuable_collection, collection_type)
+      # map has to be used here since using pluck or select will
+      # throw an error when ordering issuables by priority which inserts
+      # a new order into the collection.
+      # We cannot use reorder to not mess up the paginated collection.
+      issuable_ids = issuable_collection.map(&:id)
+
+      return {} if issuable_ids.empty?
+
+      issuable_note_count = ::Note.count_for_collection(issuable_ids, collection_type)
+      issuable_votes_count = ::AwardEmoji.votes_for_collection(issuable_ids, collection_type)
+      issuable_merge_requests_count =
+        if collection_type == 'Issue'
+          ::MergeRequestsClosingIssues.count_for_collection(issuable_ids)
+        else
+          []
+        end
+
+      issuable_ids.each_with_object({}) do |id, issuable_meta|
+        downvotes = issuable_votes_count.find { |votes| votes.awardable_id == id && votes.downvote? }
+        upvotes = issuable_votes_count.find { |votes| votes.awardable_id == id && votes.upvote? }
+        notes = issuable_note_count.find { |notes| notes.noteable_id == id }
+        merge_requests = issuable_merge_requests_count.find { |mr| mr.first == id }
+
+        issuable_meta[id] = ::Issuable::IssuableMeta.new(
+          upvotes.try(:count).to_i,
+          downvotes.try(:count).to_i,
+          notes.try(:count).to_i,
+          merge_requests.try(:last).to_i
+        )
+      end
+    end
+  end
+end