Add specs for Admin::InvitesController (#9471)

spec/controllers/admin/invites_controller_spec.rb

+# frozen_string_literal: true
+
 require 'rails_helper'
 
 describe Admin::InvitesController do
@@ -40,4 +42,18 @@ describe Admin::InvitesController do
       expect(invite.reload).to be_expired
     end
   end
+
+  describe 'POST #deactivate_all' do
+    it 'expires all invites, then redirects to admin_invites_path' do
+      invites = Fabricate.times(2, :invite, expires_at: nil)
+
+      post :deactivate_all
+
+      invites.each do |invite|
+        expect(invite.reload).to be_expired
+      end
+
+      expect(response).to redirect_to admin_invites_path
+    end
+  end
 end