tests.rs

				10,
				RewardDestination::Staked,
				false,
			)
			.unwrap();

			assert_eq!(Bonded::<Test>::get(stash), Some(controller));
			assert_eq!(Ledger::<Test>::get(controller).map(|l| l.stash), Some(stash));

			// existing controller should not be able become a stash.
			assert_noop!(
				Staking::bond(RuntimeOrigin::signed(controller), 10, RewardDestination::Staked),
				Error::<Test>::AlreadyPaired,
			);
		})
	}

	#[test]
	fn is_bonded_works() {
		ExtBuilder::default().build_and_execute(|| {
			assert!(!StakingLedger::<Test>::is_bonded(StakingAccount::Stash(42)));
			assert!(!StakingLedger::<Test>::is_bonded(StakingAccount::Controller(42)));

			// adds entry to Bonded without Ledger pair (should not happen).
			<Bonded<Test>>::insert(42, 42);
			assert!(!StakingLedger::<Test>::is_bonded(StakingAccount::Controller(42)));

			assert_eq!(<Bonded<Test>>::get(&11), Some(11));
			assert!(StakingLedger::<Test>::is_bonded(StakingAccount::Stash(11)));
			assert!(StakingLedger::<Test>::is_bonded(StakingAccount::Controller(11)));

			<Bonded<Test>>::remove(42); // ensures try-state checks pass.
		})
	}

	#[test]
	#[allow(deprecated)]
	fn set_payee_errors_on_controller_destination() {
		ExtBuilder::default().build_and_execute(|| {
			Payee::<Test>::insert(11, RewardDestination::Staked);
			assert_noop!(
				Staking::set_payee(RuntimeOrigin::signed(11), RewardDestination::Controller),
				Error::<Test>::ControllerDeprecated
			);
			assert_eq!(Payee::<Test>::get(&11), Some(RewardDestination::Staked));
		})
	}

	#[test]
	#[allow(deprecated)]
	fn update_payee_migration_works() {
		ExtBuilder::default().build_and_execute(|| {
			// migrate a `Controller` variant to `Account` variant.
			Payee::<Test>::insert(11, RewardDestination::Controller);
			assert_eq!(Payee::<Test>::get(&11), Some(RewardDestination::Controller));
			assert_ok!(Staking::update_payee(RuntimeOrigin::signed(11), 11));
			assert_eq!(Payee::<Test>::get(&11), Some(RewardDestination::Account(11)));

			// Do not migrate a variant if not `Controller`.
			Payee::<Test>::insert(21, RewardDestination::Stash);
			assert_eq!(Payee::<Test>::get(&21), Some(RewardDestination::Stash));
			assert_noop!(
				Staking::update_payee(RuntimeOrigin::signed(11), 21),
				Error::<Test>::NotController
			);
			assert_eq!(Payee::<Test>::get(&21), Some(RewardDestination::Stash));
		})
	}

	#[test]
	fn deprecate_controller_batch_works_full_weight() {
		ExtBuilder::default().build_and_execute(|| {
			// Given:

			let start = 1001;
			let mut controllers: Vec<_> = vec![];
			for n in start..(start + MaxControllersInDeprecationBatch::get()).into() {
				let ctlr: u64 = n.into();
				let stash: u64 = (n + 10000).into();

				Ledger::<Test>::insert(
					ctlr,
					StakingLedger {
						controller: None,
						total: (10 + ctlr).into(),
						active: (10 + ctlr).into(),
						..StakingLedger::default_from(stash)
					},
				);
				Bonded::<Test>::insert(stash, ctlr);
				Payee::<Test>::insert(stash, RewardDestination::Staked);

				controllers.push(ctlr);
			}

			// When:

			let bounded_controllers: BoundedVec<
				_,
				<Test as Config>::MaxControllersInDeprecationBatch,
			> = BoundedVec::try_from(controllers).unwrap();

			// Only `AdminOrigin` can sign.
			assert_noop!(
				Staking::deprecate_controller_batch(
					RuntimeOrigin::signed(2),
					bounded_controllers.clone()
				),
				BadOrigin
			);

			let result =
				Staking::deprecate_controller_batch(RuntimeOrigin::root(), bounded_controllers);
			assert_ok!(result);
			assert_eq!(
				result.unwrap().actual_weight.unwrap(),
				<Test as Config>::WeightInfo::deprecate_controller_batch(
					<Test as Config>::MaxControllersInDeprecationBatch::get()
				)
			);

			// Then:

			for n in start..(start + MaxControllersInDeprecationBatch::get()).into() {
				let ctlr: u64 = n.into();
				let stash: u64 = (n + 10000).into();

				// Ledger no longer keyed by controller.
				assert_eq!(Ledger::<Test>::get(ctlr), None);
				// Bonded now maps to the stash.
				assert_eq!(Bonded::<Test>::get(stash), Some(stash));

				// Ledger is now keyed by stash.
				let ledger_updated = Ledger::<Test>::get(stash).unwrap();
				assert_eq!(ledger_updated.stash, stash);

				// Check `active` and `total` values match the original ledger set by controller.
				assert_eq!(ledger_updated.active, (10 + ctlr).into());
				assert_eq!(ledger_updated.total, (10 + ctlr).into());
			}
		})
	}

	#[test]
	fn deprecate_controller_batch_works_half_weight() {
		ExtBuilder::default().build_and_execute(|| {
			// Given:

			let start = 1001;
			let mut controllers: Vec<_> = vec![];
			for n in start..(start + MaxControllersInDeprecationBatch::get()).into() {
				let ctlr: u64 = n.into();

				// Only half of entries are unique pairs.
				let stash: u64 = if n % 2 == 0 { (n + 10000).into() } else { ctlr };

				Ledger::<Test>::insert(
					ctlr,
					StakingLedger { controller: None, ..StakingLedger::default_from(stash) },
				);
				Bonded::<Test>::insert(stash, ctlr);
				Payee::<Test>::insert(stash, RewardDestination::Staked);

				controllers.push(ctlr);
			}

			// When:
			let bounded_controllers: BoundedVec<
				_,
				<Test as Config>::MaxControllersInDeprecationBatch,
			> = BoundedVec::try_from(controllers.clone()).unwrap();

			let result =
				Staking::deprecate_controller_batch(RuntimeOrigin::root(), bounded_controllers);
			assert_ok!(result);
			assert_eq!(
				result.unwrap().actual_weight.unwrap(),
				<Test as Config>::WeightInfo::deprecate_controller_batch(controllers.len() as u32)
			);

			// Then:

			for n in start..(start + MaxControllersInDeprecationBatch::get()).into() {
				let unique_pair = n % 2 == 0;
				let ctlr: u64 = n.into();
				let stash: u64 = if unique_pair { (n + 10000).into() } else { ctlr };

				// Side effect of migration for unique pair.
				if unique_pair {
					assert_eq!(Ledger::<Test>::get(ctlr), None);
				}
				// Bonded maps to the stash.
				assert_eq!(Bonded::<Test>::get(stash), Some(stash));

				// Ledger is keyed by stash.
				let ledger_updated = Ledger::<Test>::get(stash).unwrap();
				assert_eq!(ledger_updated.stash, stash);
			}
		})
	}

	#[test]
	fn deprecate_controller_batch_skips_unmigrated_controller_payees() {
		ExtBuilder::default().try_state(false).build_and_execute(|| {
			// Given:

			let stash: u64 = 1000;
			let ctlr: u64 = 1001;

			Ledger::<Test>::insert(
				ctlr,
				StakingLedger { controller: None, ..StakingLedger::default_from(stash) },
			);
			Bonded::<Test>::insert(stash, ctlr);
			#[allow(deprecated)]
			Payee::<Test>::insert(stash, RewardDestination::Controller);

			// When:

			let bounded_controllers: BoundedVec<
				_,
				<Test as Config>::MaxControllersInDeprecationBatch,
			> = BoundedVec::try_from(vec![ctlr]).unwrap();

			let result =
				Staking::deprecate_controller_batch(RuntimeOrigin::root(), bounded_controllers);
			assert_ok!(result);
			assert_eq!(
				result.unwrap().actual_weight.unwrap(),
				<Test as Config>::WeightInfo::deprecate_controller_batch(1 as u32)
			);

			// Then:

			// Esure deprecation did not happen.
			assert_eq!(Ledger::<Test>::get(ctlr).is_some(), true);

			// Bonded still keyed by controller.
			assert_eq!(Bonded::<Test>::get(stash), Some(ctlr));

			// Ledger is still keyed by controller.
			let ledger_updated = Ledger::<Test>::get(ctlr).unwrap();
			assert_eq!(ledger_updated.stash, stash);
		})
	}

	#[test]
	fn deprecate_controller_batch_with_bad_state_ok() {
		ExtBuilder::default().has_stakers(false).nominate(false).build_and_execute(|| {
			setup_double_bonded_ledgers();

			// now let's deprecate all the controllers for all the existing ledgers.
			let bounded_controllers: BoundedVec<
				_,
				<Test as Config>::MaxControllersInDeprecationBatch,
			> = BoundedVec::try_from(vec![1, 2, 3, 4]).unwrap();

			assert_ok!(Staking::deprecate_controller_batch(
				RuntimeOrigin::root(),
				bounded_controllers
			));

			assert_eq!(
				*staking_events().last().unwrap(),
				Event::ControllerBatchDeprecated { failures: 0 }
			);
		})
	}

	#[test]
	fn deprecate_controller_batch_with_bad_state_failures() {
		ExtBuilder::default().has_stakers(false).try_state(false).build_and_execute(|| {
			setup_double_bonded_ledgers();

			// now let's deprecate all the controllers for all the existing ledgers.
			let bounded_controllers: BoundedVec<
				_,
				<Test as Config>::MaxControllersInDeprecationBatch,
			> = BoundedVec::try_from(vec![4, 3, 2, 1]).unwrap();

			assert_ok!(Staking::deprecate_controller_batch(
				RuntimeOrigin::root(),
				bounded_controllers
			));

			assert_eq!(
				*staking_events().last().unwrap(),
				Event::ControllerBatchDeprecated { failures: 2 }
			);
		})
	}

	#[test]
	fn set_controller_with_bad_state_ok() {
		ExtBuilder::default().has_stakers(false).nominate(false).build_and_execute(|| {
			setup_double_bonded_ledgers();

			// in this case, setting controller works due to the ordering of the calls.
			assert_ok!(Staking::set_controller(RuntimeOrigin::signed(1)));
			assert_ok!(Staking::set_controller(RuntimeOrigin::signed(2)));
			assert_ok!(Staking::set_controller(RuntimeOrigin::signed(3)));
		})
	}

	#[test]
	fn set_controller_with_bad_state_fails() {
		ExtBuilder::default().has_stakers(false).try_state(false).build_and_execute(|| {
			setup_double_bonded_ledgers();

			// setting the controller of ledger associated with stash 3 fails since its stash is a
			// controller of another ledger.
			assert_noop!(
				Staking::set_controller(RuntimeOrigin::signed(3)),
				Error::<Test>::BadState
			);
			assert_noop!(
				Staking::set_controller(RuntimeOrigin::signed(2)),
				Error::<Test>::BadState
			);
			assert_ok!(Staking::set_controller(RuntimeOrigin::signed(1)));
		})
	}
}