Fix false-positive N+1 tests

ee/spec/serializers/ee/environment_serializer_spec.rb

@@ -11,10 +11,10 @@ RSpec.describe EE::EnvironmentSerializer do
   end
 
   before do
-    stub_licensed_features(environment_alerts: true)
+    stub_licensed_features(environment_alerts: true, protected_environments: true)
   end
 
-  it_behaves_like 'avoid N+1 on environments serialization'
+  it_behaves_like 'avoid N+1 on environments serialization', ee: true
 
   def create_environment_with_associations(project)
     create(:environment, project: project).tap do |environment|

spec/support/shared_examples/serializers/environment_serializer_shared_examples.rb

 # frozen_string_literal: true
-RSpec.shared_examples 'avoid N+1 on environments serialization' do
+RSpec.shared_examples 'avoid N+1 on environments serialization' do |ee: false|
+  # Investigating in https://gitlab.com/gitlab-org/gitlab/-/issues/353209
+  let(:query_threshold) { 50 + (ee ? 4 : 0) }
+
   it 'avoids N+1 database queries with grouping', :request_store do
     create_environment_with_associations(project)
 
     control = ActiveRecord::QueryRecorder.new { serialize(grouping: true) }
 
+    create_environment_with_associations(project)
     create_environment_with_associations(project)
 
-    expect { serialize(grouping: true) }.not_to exceed_query_limit(control.count)
+    expect { serialize(grouping: true) }
+      .not_to exceed_query_limit(control.count)
+      .with_threshold(query_threshold)
   end
 
   it 'avoids N+1 database queries without grouping', :request_store do
@@ -15,9 +21,12 @@ RSpec.shared_examples 'avoid N+1 on environments serialization' do
 
     control = ActiveRecord::QueryRecorder.new { serialize(grouping: false) }
 
+    create_environment_with_associations(project)
     create_environment_with_associations(project)
 
-    expect { serialize(grouping: false) }.not_to exceed_query_limit(control.count)
+    expect { serialize(grouping: false) }
+      .not_to exceed_query_limit(control.count)
+      .with_threshold(query_threshold)
   end
 
   it 'does not preload for environments that does not exist in the page', :request_store do
@@ -35,7 +44,7 @@ RSpec.shared_examples 'avoid N+1 on environments serialization' do
   end
 
   def serialize(grouping:, query: nil)
-    query ||= { page: 1, per_page: 1 }
+    query ||= { page: 1, per_page: 20 }
     request = double(url: "#{Gitlab.config.gitlab.url}:8080/api/v4/projects?#{query.to_query}", query_parameters: query)
 
     EnvironmentSerializer.new(current_user: user, project: project).yield_self do |serializer|