1 files changed, 63 insertions, 0 deletions
diff --git a/spec/requests/api/graphql/project/merge_request/pipelines_spec.rb b/spec/requests/api/graphql/project/merge_request/pipelines_spec.rb
new file mode 100644
index 00000000000..ac0b18a37d6
--- /dev/null
+++ b/spec/requests/api/graphql/project/merge_request/pipelines_spec.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Query.project.mergeRequests.pipelines' do
+  include GraphqlHelpers
+
+  let_it_be(:project) { create(:project, :public, :repository) }
+  let_it_be(:author) { create(:user) }
+  let_it_be(:merge_requests) do
+    %i[with_diffs with_image_diffs conflict].map do |trait|
+      create(:merge_request, trait, author: author, source_project: project)
+    end
+  end
+
+  describe '.count' do
+    let(:query) do
+      <<~GQL
+      query($path: ID!, $first: Int) {
+        project(fullPath: $path) {
+          mergeRequests(first: $first) {
+            nodes {
+              iid
+              pipelines {
+                count
+              }
+            }
+          }
+        }
+      }
+      GQL
+    end
+
+    def run_query(first = nil)
+      post_graphql(query, current_user: author, variables: { path: project.full_path, first: first })
+    end
+
+    before do
+      merge_requests.each do |mr|
+        shas = mr.all_commits.limit(2).pluck(:sha)
+
+        shas.each do |sha|
+          create(:ci_pipeline, :success, project: project, ref: mr.source_branch, sha: sha)
+        end
+      end
+    end
+
+    it 'produces correct results' do
+      run_query(2)
+
+      p_nodes = graphql_data_at(:project, :merge_requests, :nodes)
+
+      expect(p_nodes).to all(match('iid' => be_present, 'pipelines' => match('count' => 2)))
+    end
+
+    it 'is scalable', :request_store, :use_clean_rails_memory_store_caching do
+      # warm up
+      run_query
+
+      expect { run_query(2) }.to(issue_same_number_of_queries_as { run_query(1) }.ignoring_cached_queries)
+    end
+  end
+end