paras_registrar.rs

			assert_ok!(Registrar::make_parachain(para_1));

			run_to_session(4);

			// Roles are as we expect
			assert!(Parachains::is_parachain(para_1));
			assert!(!Parachains::is_parathread(para_1));
			assert!(!Parachains::is_parachain(para_2));
			assert!(Parachains::is_parathread(para_2));

			// Both paras initiate a swap
			assert_ok!(Registrar::swap(para_origin(para_1), para_1, para_2,));
			assert_ok!(Registrar::swap(para_origin(para_2), para_2, para_1,));

			run_to_session(6);

			// Deregister a parathread that was originally a parachain
			assert_eq!(Parachains::lifecycle(para_1), Some(ParaLifecycle::Parathread));
			assert_ok!(Registrar::deregister(
				runtime_parachains::Origin::Parachain(para_1).into(),
				para_1
			));

			run_to_block(21);

			// Roles are swapped
			assert!(!Parachains::is_parachain(para_1));
			assert!(Parachains::is_parathread(para_1));
			assert!(Parachains::is_parachain(para_2));
			assert!(!Parachains::is_parathread(para_2));
		});
	}

	#[test]
	fn para_lock_works() {
		new_test_ext().execute_with(|| {
			run_to_block(1);

			assert_ok!(Registrar::reserve(Origin::signed(1)));
			let para_id = LOWEST_PUBLIC_ID;
			assert_ok!(Registrar::register(
				Origin::signed(1),
				para_id,
				vec![1; 3].into(),
				vec![1, 2, 3].into(),
			));

			// Owner can call swap
			assert_ok!(Registrar::swap(Origin::signed(1), para_id, para_id + 1));

			// 2 session changes to fully onboard.
			run_to_session(2);
			assert_eq!(Parachains::lifecycle(para_id), Some(ParaLifecycle::Parathread));

			// Once they begin onboarding, we lock them in.
			assert_ok!(Registrar::make_parachain(para_id));

			// Owner cannot call swap anymore
			assert_noop!(Registrar::swap(Origin::signed(1), para_id, para_id + 2), BadOrigin);
		});
	}
}

#[cfg(feature = "runtime-benchmarks")]
mod benchmarking {
	use super::{Pallet as Registrar, *};
	use crate::traits::Registrar as RegistrarT;
	use frame_support::assert_ok;
	use frame_system::RawOrigin;
	use runtime_parachains::{paras, shared, Origin as ParaOrigin};
	use sp_runtime::traits::Bounded;

	use frame_benchmarking::{account, benchmarks, whitelisted_caller};

	fn assert_last_event<T: Config>(generic_event: <T as Config>::Event) {
		let events = frame_system::Pallet::<T>::events();
		let system_event: <T as frame_system::Config>::Event = generic_event.into();
		// compare to the last event record
		let frame_system::EventRecord { event, .. } = &events[events.len() - 1];
		assert_eq!(event, &system_event);
	}

	fn register_para<T: Config>(id: u32) -> ParaId {
		let para = ParaId::from(id);
		let genesis_head = Registrar::<T>::worst_head_data();
		let validation_code = Registrar::<T>::worst_validation_code();
		let caller: T::AccountId = whitelisted_caller();
		T::Currency::make_free_balance_be(&caller, BalanceOf::<T>::max_value());
		assert_ok!(Registrar::<T>::reserve(RawOrigin::Signed(caller.clone()).into()));
		assert_ok!(Registrar::<T>::register(
			RawOrigin::Signed(caller).into(),
			para,
			genesis_head,
			validation_code
		));
		return para
	}

	fn para_origin(id: u32) -> ParaOrigin {
		ParaOrigin::Parachain(id.into())
	}

	// This function moves forward to the next scheduled session for parachain lifecycle upgrades.
	fn next_scheduled_session<T: Config>() {
		shared::Pallet::<T>::set_session_index(shared::Pallet::<T>::scheduled_session());
		paras::Pallet::<T>::test_on_new_session();
	}

	benchmarks! {
		where_clause { where ParaOrigin: Into<<T as frame_system::Config>::Origin> }

		reserve {
			let caller: T::AccountId = whitelisted_caller();
			T::Currency::make_free_balance_be(&caller, BalanceOf::<T>::max_value());
		}: _(RawOrigin::Signed(caller.clone()))
		verify {
			assert_last_event::<T>(Event::<T>::Reserved(LOWEST_PUBLIC_ID, caller).into());
			assert!(Paras::<T>::get(LOWEST_PUBLIC_ID).is_some());
			assert_eq!(paras::Pallet::<T>::lifecycle(LOWEST_PUBLIC_ID), None);
		}

		register {
			let para = LOWEST_PUBLIC_ID;
			let genesis_head = Registrar::<T>::worst_head_data();
			let validation_code = Registrar::<T>::worst_validation_code();
			let caller: T::AccountId = whitelisted_caller();
			T::Currency::make_free_balance_be(&caller, BalanceOf::<T>::max_value());
			assert_ok!(Registrar::<T>::reserve(RawOrigin::Signed(caller.clone()).into()));
		}: _(RawOrigin::Signed(caller.clone()), para, genesis_head, validation_code)
		verify {
			assert_last_event::<T>(Event::<T>::Registered(para, caller).into());
			assert_eq!(paras::Pallet::<T>::lifecycle(para), Some(ParaLifecycle::Onboarding));
			next_scheduled_session::<T>();
			assert_eq!(paras::Pallet::<T>::lifecycle(para), Some(ParaLifecycle::Parathread));
		}

		force_register {
			let manager: T::AccountId = account("manager", 0, 0);
			let deposit = 0u32.into();
			let para = ParaId::from(69);
			let genesis_head = Registrar::<T>::worst_head_data();
			let validation_code = Registrar::<T>::worst_validation_code();
		}: _(RawOrigin::Root, manager.clone(), deposit, para, genesis_head, validation_code)
		verify {
			assert_last_event::<T>(Event::<T>::Registered(para, manager).into());
			assert_eq!(paras::Pallet::<T>::lifecycle(para), Some(ParaLifecycle::Onboarding));
			next_scheduled_session::<T>();
			assert_eq!(paras::Pallet::<T>::lifecycle(para), Some(ParaLifecycle::Parathread));
		}

		deregister {
			let para = register_para::<T>(LOWEST_PUBLIC_ID.into());
			next_scheduled_session::<T>();
			let caller: T::AccountId = whitelisted_caller();
		}: _(RawOrigin::Signed(caller), para)
		verify {
			assert_last_event::<T>(Event::<T>::Deregistered(para).into());
		}

		swap {
			let parathread = register_para::<T>(LOWEST_PUBLIC_ID.into());
			let parachain = register_para::<T>((LOWEST_PUBLIC_ID + 1).into());

			let parachain_origin = para_origin(parachain.into());

			// Actually finish registration process
			next_scheduled_session::<T>();

			// Upgrade the parachain
			Registrar::<T>::make_parachain(parachain)?;
			next_scheduled_session::<T>();

			assert_eq!(paras::Pallet::<T>::lifecycle(parachain), Some(ParaLifecycle::Parachain));
			assert_eq!(paras::Pallet::<T>::lifecycle(parathread), Some(ParaLifecycle::Parathread));

			let caller: T::AccountId = whitelisted_caller();
			Registrar::<T>::swap(parachain_origin.into(), parachain, parathread)?;
		}: _(RawOrigin::Signed(caller.clone()), parathread, parachain)
		verify {
			next_scheduled_session::<T>();
			// Swapped!
			assert_eq!(paras::Pallet::<T>::lifecycle(parachain), Some(ParaLifecycle::Parathread));
			assert_eq!(paras::Pallet::<T>::lifecycle(parathread), Some(ParaLifecycle::Parachain));
		}

		impl_benchmark_test_suite!(
			Registrar,
			crate::integration_tests::new_test_ext(),
			crate::integration_tests::Test,
		);
	}
}