Add feature flag and fix sorting logic

Added feature flag `project_finder_similarity_sort`
Put the sorting in the conditional

app/finders/projects_finder.rb

@@ -49,14 +49,13 @@ class ProjectsFinder < UnionFinder
 
     use_cte = params.delete(:use_cte)
     collection = Project.wrap_with_cte(collection) if use_cte
+    collection = filter_projects(collection)
 
-    collection = if params[:sort] == 'similarity' && params[:search]
-                   by_search(collection).sorted_by_similarity_desc(params[:search])
-                 else
-                   filter_projects(collection)
-                 end
-
-    sort(collection)
+    if params[:sort] == 'similarity' && params[:search] && Feature.enabled?(:project_finder_similarity_sort)
+      collection.sorted_by_similarity_desc(params[:search])
+    else
+      sort(collection)
+    end
   end
 
   private

config/feature_flags/development/project_finder_similarity_sort.yml

+---
+name: project_finder_similarity_sort
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43136
+rollout_issue_url:
+type: development
+group: group::threat_insights
+default_enabled: false

ee/app/assets/javascripts/security_dashboard/components/first_class_project_manager/project_manager.vue

@@ -223,6 +223,7 @@ export default {
           first: this.$options.PROJECTS_PER_PAGE,
           after: pageInfo.endCursor,
           searchNamespaces: true,
+          sort: 'similarity',
         },
       });
     },

ee/spec/frontend/security_dashboard/components/first_class_project_manager/project_manager_spec.js

@@ -87,6 +87,7 @@ describe('Project Manager component', () => {
           first: wrapper.vm.$options.PROJECTS_PER_PAGE,
           after: '',
           searchNamespaces: true,
+          sort: 'similarity',
         },
       });
     });

spec/finders/projects_finder_spec.rb

@@ -31,6 +31,10 @@ RSpec.describe ProjectsFinder, :do_not_mock_admin_mode do
     let(:use_cte) { true }
     let(:finder) { described_class.new(params: params.merge(use_cte: use_cte), current_user: current_user, project_ids_relation: project_ids_relation) }
 
+    before do
+      stub_feature_flags(project_finder_similarity_sort: false)
+    end
+
     subject { finder.execute }
 
     shared_examples 'ProjectFinder#execute examples' do
@@ -325,6 +329,10 @@ RSpec.describe ProjectsFinder, :do_not_mock_admin_mode do
             create(:project, :internal, group: group, name: 'projAB', path: 'projAB')
           end
 
+          before do
+            stub_feature_flags(project_finder_similarity_sort: true)
+          end
+
           it { is_expected.to eq([internal_project2, internal_project4, internal_project3]) }
         end
       end

spec/graphql/resolvers/projects_resolver_spec.rb

@@ -27,6 +27,10 @@ RSpec.describe Resolvers::ProjectsResolver do
       private_group.add_developer(user)
     end
 
+    before do
+      stub_feature_flags(project_finder_similarity_sort: false)
+    end
+
     context 'when user is not logged in' do
       let(:current_user) { nil }
 
@@ -118,14 +122,20 @@ RSpec.describe Resolvers::ProjectsResolver do
         end
 
         context 'when sort is similarity' do
-          let_it_be(:named_project1) { create(:project, :public, name: 'projABC', path: 'projABC') }
-          let_it_be(:named_project2) { create(:project, :public, name: 'projA', path: 'projA') }
-          let_it_be(:named_project3) { create(:project, :public, name: 'projAB', path: 'projAB') }
+          let_it_be(:named_project1) { create(:project, :public, name: 'projAB', path: 'projAB') }
+          let_it_be(:named_project2) { create(:project, :public, name: 'projABC', path: 'projABC') }
+          let_it_be(:named_project3) { create(:project, :public, name: 'projA', path: 'projA') }
 
           let(:filters) { { search: 'projA', sort: 'similarity' } }
 
           it 'returns projects in order of similarity to search' do
-            is_expected.to match_array([named_project2, named_project3, named_project1])
+            stub_feature_flags(project_finder_similarity_sort: true)
+
+            is_expected.to eq([named_project3, named_project1, named_project2])
+          end
+
+          it 'returns projects not in order of similarity to search if flag is off' do
+            is_expected.not_to eq([named_project3, named_project1, named_project2])
           end
         end
       end