Exclude project namespace when computing subgroup counts

When loading counts for group lists exclude project namespaces
from subgroup counts

app/models/concerns/loaded_in_group_list.rb

@@ -41,9 +41,11 @@ module LoadedInGroupList
       namespaces = Namespace.arel_table
       children = namespaces.alias('children')
 
+      # TODO 6473: remove the filtering of the Namespaces::ProjectNamespace see https://gitlab.com/groups/gitlab-org/-/epics/6473
       namespaces.project(Arel.star.count.as('preloaded_subgroup_count'))
         .from(children)
         .where(children[:parent_id].eq(namespaces[:id]))
+        .where(children[:type].is_distinct_from(Namespaces::ProjectNamespace.sti_name))
     end
 
     def member_count_sql

spec/models/concerns/loaded_in_group_list_spec.rb

@@ -3,49 +3,67 @@
 require 'spec_helper'
 
 RSpec.describe LoadedInGroupList do
-  let(:parent) { create(:group) }
+  let_it_be(:parent) { create(:group) }
+  let_it_be(:group) { create(:group, parent: parent) }
+  let_it_be(:project) { create(:project, namespace: parent) }
 
-  subject(:found_group) { Group.with_selects_for_list.find_by(id: parent.id) }
+  let(:archived_parameter) { nil }
 
-  describe '.with_selects_for_list' do
-    it 'includes the preloaded counts for groups' do
-      create(:group, parent: parent)
-      create(:project, namespace: parent)
-      parent.add_developer(create(:user))
+  before do
+    parent.add_developer(create(:user))
+  end
 
-      found_group = Group.with_selects_for_list.find_by(id: parent.id)
+  subject(:found_group) { Group.with_selects_for_list(archived: archived_parameter).find_by(id: parent.id) }
 
+  describe '.with_selects_for_list' do
+    it 'includes the preloaded counts for groups' do
       expect(found_group.preloaded_project_count).to eq(1)
       expect(found_group.preloaded_subgroup_count).to eq(1)
       expect(found_group.preloaded_member_count).to eq(1)
     end
 
+    context 'with project namespaces' do
+      let_it_be(:group1) { create(:group, parent: parent) }
+      let_it_be(:group2) { create(:group, parent: parent) }
+      let_it_be(:project_namespace) { create(:project_namespace, project: project) }
+
+      it 'does not include project_namespaces in the count of subgroups' do
+        expect(found_group.preloaded_subgroup_count).to eq(3)
+        expect(parent.subgroup_count).to eq(3)
+      end
+    end
+
     context 'with archived projects' do
-      it 'counts including archived projects when `true` is passed' do
-        create(:project, namespace: parent, archived: true)
-        create(:project, namespace: parent)
+      let_it_be(:archived_project) { create(:project, namespace: parent, archived: true) }
 
-        found_group = Group.with_selects_for_list(archived: 'true').find_by(id: parent.id)
+      let(:archived_parameter) { true }
 
+      it 'counts including archived projects when `true` is passed' do
         expect(found_group.preloaded_project_count).to eq(2)
       end
 
-      it 'counts only archived projects when `only` is passed' do
-        create_list(:project, 2, namespace: parent, archived: true)
-        create(:project, namespace: parent)
+      context 'when not counting archived projects' do
+        let(:archived_parameter) { false }
+
+        it 'counts projects without archived ones' do
+          expect(found_group.preloaded_project_count).to eq(1)
+        end
+      end
+
+      context 'with archived only' do
+        let_it_be(:archived_project2) { create(:project, namespace: parent, archived: true) }
 
-        found_group = Group.with_selects_for_list(archived: 'only').find_by(id: parent.id)
+        let(:archived_parameter) { 'only' }
 
-        expect(found_group.preloaded_project_count).to eq(2)
+        it 'counts only archived projects when `only` is passed' do
+          expect(found_group.preloaded_project_count).to eq(2)
+        end
       end
     end
   end
 
   describe '#children_count' do
     it 'counts groups and projects' do
-      create(:group, parent: parent)
-      create(:project, namespace: parent)
-
       expect(found_group.children_count).to eq(2)
     end
   end