Exclude project namespaces from routes

Excludes project namespaces in autocomplete routes finder.

app/finders/autocomplete/routes_finder.rb

@@ -30,7 +30,7 @@ module Autocomplete
 
     class NamespacesOnly < self
       def routables
-        return Namespace.all if current_user.admin?
+        return Namespace.without_project_namespaces if current_user.admin?
 
         current_user.namespaces
       end

spec/finders/autocomplete/routes_finder_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Autocomplete::RoutesFinder do
+  describe '#execute' do
+    let_it_be(:user) { create(:user, username: 'user_path') }
+    let_it_be(:admin) { create(:admin) }
+    let_it_be(:group) { create(:group, path: 'path1') }
+    let_it_be(:group2) { create(:group, path: 'path2') }
+    let_it_be(:group3) { create(:group, path: 'not-matching') }
+    let_it_be(:project) { create(:project, path: 'path3', namespace: user.namespace) }
+    let_it_be(:project2) { create(:project, path: 'path4') }
+    let_it_be(:project_namespace) { create(:project_namespace, parent: group, path: 'path5') }
+
+    let(:current_user) { user }
+    let(:search) { 'path' }
+
+    before do
+      group.add_owner(user)
+    end
+
+    context 'for NamespacesOnly' do
+      subject { Autocomplete::RoutesFinder::NamespacesOnly.new(current_user, search: search).execute }
+
+      let(:user_route) { Route.find_by_path(user.username) }
+
+      it 'finds only user namespace and groups matching the search excluding project namespaces' do
+        is_expected.to match_array([group.route, user_route])
+      end
+
+      context 'when user is admin' do
+        let(:current_user) { admin }
+
+        it 'finds all namespaces matching the search excluding project namespaces' do
+          is_expected.to match_array([group.route, group2.route, user_route])
+        end
+      end
+    end
+
+    context 'for ProjectsOnly' do
+      subject { Autocomplete::RoutesFinder::ProjectsOnly.new(current_user, search: 'path').execute }
+
+      it 'finds only matching projects the user has access to' do
+        is_expected.to match_array([project.route])
+      end
+
+      context 'when user is admin' do
+        let(:current_user) { admin }
+
+        it 'finds all projects matching the search' do
+          is_expected.to match_array([project.route, project2.route])
+        end
+      end
+    end
+  end
+end