Move change_repository_storage to BasePolicy

The change_repository_storage policy will be used
not only for Project repositories, but also
PersonalSnippet and ProjectSnippet repositories,
so it should be moved out of ProjectPolicy

app/policies/base_policy.rb

@@ -57,6 +57,8 @@ class BasePolicy < DeclarativePolicy::Base
   rule { default }.enable :read_cross_project
 
   condition(:is_gitlab_com) { ::Gitlab.dev_env_or_com? }
+
+  rule { admin }.enable :change_repository_storage
 end
 
 BasePolicy.prepend_if_ee('EE::BasePolicy')

app/policies/project_policy.rb

@@ -546,8 +546,6 @@ class ProjectPolicy < BasePolicy
     prevent :create_pipeline
   end
 
-  rule { admin }.enable :change_repository_storage
-
   rule { can?(:read_issue) }.policy do
     enable :read_design
     enable :read_design_activity

spec/policies/base_policy_spec.rb

@@ -22,6 +22,34 @@ RSpec.describe BasePolicy do
     end
   end
 
+  shared_examples 'admin only access' do |policy|
+    let(:current_user) { build_stubbed(:user) }
+
+    subject { described_class.new(current_user, nil) }
+
+    it { is_expected.not_to be_allowed(policy) }
+
+    context 'for admins' do
+      let(:current_user) { build_stubbed(:admin) }
+
+      it 'allowed when in admin mode' do
+        enable_admin_mode!(current_user)
+
+        is_expected.to be_allowed(policy)
+      end
+
+      it 'prevented when not in admin mode' do
+        is_expected.not_to be_allowed(policy)
+      end
+    end
+
+    context 'for anonymous' do
+      let(:current_user) { nil }
+
+      it { is_expected.not_to be_allowed(policy) }
+    end
+  end
+
   describe 'read cross project' do
     let(:current_user) { build_stubbed(:user) }
     let(:user) { build_stubbed(:user) }
@@ -41,51 +69,15 @@ RSpec.describe BasePolicy do
         enable_external_authorization_service_check
       end
 
-      it { is_expected.not_to be_allowed(:read_cross_project) }
-
-      context 'for admins' do
-        let(:current_user) { build_stubbed(:admin) }
-
-        subject { described_class.new(current_user, nil) }
-
-        it 'allowed when in admin mode' do
-          enable_admin_mode!(current_user)
-
-          is_expected.to be_allowed(:read_cross_project)
-        end
-
-        it 'prevented when not in admin mode' do
-          is_expected.not_to be_allowed(:read_cross_project)
-        end
-      end
-
-      context 'for anonymous' do
-        let(:current_user) { nil }
-
-        it { is_expected.not_to be_allowed(:read_cross_project) }
-      end
+      it_behaves_like 'admin only access', :read_cross_project
     end
   end
 
   describe 'full private access' do
-    let(:current_user) { build_stubbed(:user) }
-
-    subject { described_class.new(current_user, nil) }
-
-    it { is_expected.not_to be_allowed(:read_all_resources) }
-
-    context 'for admins' do
-      let(:current_user) { build_stubbed(:admin) }
-
-      it 'allowed when in admin mode' do
-        enable_admin_mode!(current_user)
-
-        is_expected.to be_allowed(:read_all_resources)
-      end
+    it_behaves_like 'admin only access', :read_all_resources
+  end
 
-      it 'prevented when not in admin mode' do
-        is_expected.not_to be_allowed(:read_all_resources)
-      end
-    end
+  describe 'change_repository_storage' do
+    it_behaves_like 'admin only access', :change_repository_storage
   end
 end