Rspec: Expecting a Rake task to be called

Copyit 'deletes all Users' do
   FactroyBot.create(:user)
   expect(Rake::Task['notify:critical_operation']).to receive(:invoke)
   
   expect { described_class.clean }.to change(User, :count).from(1).to(0) 
end

Copydesc 'Some task'
task :some_task do
  SomeClass.new.run
end