Allow nomination pools to chill + fix dismantle scenario (#11426)

* make pool roles optional * undo lock file changes? * add migration * add the ability for pools to chill themselves * boilerplate of tests * somewhat stable, but I think I found another bug as well * Fix it all * Add more more sophisticated test + capture one more bug. * Update frame/staking/src/lib.rs * reduce the diff a little bit * add some test for the slashing bug * cleanup * fix lock file? * Fix * fmt * Update frame/nomination-pools/src/lib.rs Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Update frame/nomination-pools/src/lib.rs Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Update frame/nomination-pools/src/lib.rs Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Update frame/nomination-pools/src/mock.rs Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Fix build * fix some fishy tests.. * add one last integrity check for MinCreateBond * remove bad assertion -- needs to be dealt with later * nits * fix tests and add benchmarks for chill * remove stuff * fix benchmarks * cargo run --quiet --profile=production --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark pallet --chain=dev --steps=50 --repeat=20 --pallet=pallet_nomination_pools --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/nomination-pools/src/weights.rs --template=./.maintain/frame-weight-template.hbs * remove defensive Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com> Co-authored-by: Parity Bot <admin@parity.io>
2026-06-12 21:41:12 +00:00 · 2022-06-13 22:07:36 +01:00
parent 19684de7d8
commit ad1d171601
18 changed files with 1434 additions and 635 deletions
@@ -0,0 +1,373 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg(test)]
+
+mod mock;
+
+use frame_support::{assert_noop, assert_ok, bounded_btree_map, traits::Currency};
+use mock::*;
+use pallet_nomination_pools::{
+	Error as PoolsError, Event as PoolsEvent, LastPoolId, PoolMember, PoolMembers, PoolState,
+};
+use pallet_staking::{CurrentEra, Event as StakingEvent, Payee, RewardDestination};
+
+#[test]
+fn pool_lifecycle_e2e() {
+	new_test_ext().execute_with(|| {
+		assert_eq!(Balances::minimum_balance(), 5);
+		assert_eq!(Staking::current_era(), None);
+
+		// create the pool, we know this has id 1.
+		assert_ok!(Pools::create(Origin::signed(10), 50, 10, 10, 10));
+		assert_eq!(LastPoolId::<Runtime>::get(), 1);
+
+		// have the pool nominate.
+		assert_ok!(Pools::nominate(Origin::signed(10), 1, vec![1, 2, 3]));
+
+		assert_eq!(staking_events_since_last_call(), vec![StakingEvent::Bonded(POOL1_BONDED, 50),]);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Created { depositor: 10, pool_id: 1 },
+				PoolsEvent::Bonded { member: 10, pool_id: 1, bonded: 50, joined: true },
+			]
+		);
+
+		// have two members join
+		assert_ok!(Pools::join(Origin::signed(20), 10, 1));
+		assert_ok!(Pools::join(Origin::signed(21), 10, 1));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Bonded(POOL1_BONDED, 10), StakingEvent::Bonded(POOL1_BONDED, 10),]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Bonded { member: 20, pool_id: 1, bonded: 10, joined: true },
+				PoolsEvent::Bonded { member: 21, pool_id: 1, bonded: 10, joined: true },
+			]
+		);
+
+		// pool goes into destroying
+		assert_ok!(Pools::set_state(Origin::signed(10), 1, PoolState::Destroying));
+
+		// depositor cannot unbond yet.
+		assert_noop!(
+			Pools::unbond(Origin::signed(10), 10, 50),
+			PoolsError::<Runtime>::NotOnlyPoolMember,
+		);
+
+		// now the members want to unbond.
+		assert_ok!(Pools::unbond(Origin::signed(20), 20, 10));
+		assert_ok!(Pools::unbond(Origin::signed(21), 21, 10));
+
+		assert_eq!(PoolMembers::<Runtime>::get(20).unwrap().unbonding_eras.len(), 1);
+		assert_eq!(PoolMembers::<Runtime>::get(20).unwrap().points, 0);
+		assert_eq!(PoolMembers::<Runtime>::get(21).unwrap().unbonding_eras.len(), 1);
+		assert_eq!(PoolMembers::<Runtime>::get(21).unwrap().points, 0);
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+			]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::StateChanged { pool_id: 1, new_state: PoolState::Destroying },
+				PoolsEvent::Unbonded { member: 20, pool_id: 1, points: 10, balance: 10 },
+				PoolsEvent::Unbonded { member: 21, pool_id: 1, points: 10, balance: 10 },
+			]
+		);
+
+		// depositor cannot still unbond
+		assert_noop!(
+			Pools::unbond(Origin::signed(10), 10, 50),
+			PoolsError::<Runtime>::NotOnlyPoolMember,
+		);
+
+		for e in 1..BondingDuration::get() {
+			CurrentEra::<Runtime>::set(Some(e));
+			assert_noop!(
+				Pools::withdraw_unbonded(Origin::signed(20), 20, 0),
+				PoolsError::<Runtime>::CannotWithdrawAny
+			);
+		}
+
+		// members are now unlocked.
+		CurrentEra::<Runtime>::set(Some(BondingDuration::get()));
+
+		// depositor cannot still unbond
+		assert_noop!(
+			Pools::unbond(Origin::signed(10), 10, 50),
+			PoolsError::<Runtime>::NotOnlyPoolMember,
+		);
+
+		// but members can now withdraw.
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(20), 20, 0));
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(21), 21, 0));
+		assert!(PoolMembers::<Runtime>::get(20).is_none());
+		assert!(PoolMembers::<Runtime>::get(21).is_none());
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Withdrawn(POOL1_BONDED, 20),]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Withdrawn { member: 20, pool_id: 1, points: 10, balance: 10 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 20 },
+				PoolsEvent::Withdrawn { member: 21, pool_id: 1, points: 10, balance: 10 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 21 },
+			]
+		);
+
+		// as soon as all members have left, the depositor can try to unbond, but since the
+		// min-nominator intention is set, they must chill first.
+		assert_noop!(
+			Pools::unbond(Origin::signed(10), 10, 50),
+			pallet_staking::Error::<Runtime>::InsufficientBond
+		);
+
+		assert_ok!(Pools::chill(Origin::signed(10), 1));
+		assert_ok!(Pools::unbond(Origin::signed(10), 10, 50));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Chilled(POOL1_BONDED), StakingEvent::Unbonded(POOL1_BONDED, 50),]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![PoolsEvent::Unbonded { member: 10, pool_id: 1, points: 50, balance: 50 }]
+		);
+
+		// waiting another bonding duration:
+		CurrentEra::<Runtime>::set(Some(BondingDuration::get() * 2));
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(10), 10, 1));
+
+		// pools is fully destroyed now.
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Withdrawn(POOL1_BONDED, 50),]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Withdrawn { member: 10, pool_id: 1, points: 50, balance: 50 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 10 },
+				PoolsEvent::Destroyed { pool_id: 1 }
+			]
+		);
+	})
+}
+
+#[test]
+fn pool_slash_e2e() {
+	new_test_ext().execute_with(|| {
+		ExistentialDeposit::set(1);
+		assert_eq!(Balances::minimum_balance(), 1);
+		assert_eq!(Staking::current_era(), None);
+
+		// create the pool, we know this has id 1.
+		assert_ok!(Pools::create(Origin::signed(10), 40, 10, 10, 10));
+		assert_eq!(LastPoolId::<Runtime>::get(), 1);
+
+		assert_eq!(staking_events_since_last_call(), vec![StakingEvent::Bonded(POOL1_BONDED, 40)]);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Created { depositor: 10, pool_id: 1 },
+				PoolsEvent::Bonded { member: 10, pool_id: 1, bonded: 40, joined: true },
+			]
+		);
+
+		assert_eq!(Payee::<Runtime>::get(POOL1_BONDED), RewardDestination::Account(POOL1_REWARD));
+
+		// have two members join
+		assert_ok!(Pools::join(Origin::signed(20), 20, 1));
+		assert_ok!(Pools::join(Origin::signed(21), 20, 1));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Bonded(POOL1_BONDED, 20), StakingEvent::Bonded(POOL1_BONDED, 20)]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Bonded { member: 20, pool_id: 1, bonded: 20, joined: true },
+				PoolsEvent::Bonded { member: 21, pool_id: 1, bonded: 20, joined: true },
+			]
+		);
+
+		// now let's progress a bit.
+		CurrentEra::<Runtime>::set(Some(1));
+
+		// 20 / 80 of the total funds are unlocked, and safe from any further slash.
+		assert_ok!(Pools::unbond(Origin::signed(10), 10, 10));
+		assert_ok!(Pools::unbond(Origin::signed(20), 20, 10));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+				StakingEvent::Unbonded(POOL1_BONDED, 10)
+			]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Unbonded { member: 10, pool_id: 1, balance: 10, points: 10 },
+				PoolsEvent::Unbonded { member: 20, pool_id: 1, balance: 10, points: 10 }
+			]
+		);
+
+		CurrentEra::<Runtime>::set(Some(2));
+
+		// note: depositor cannot fully unbond at this point.
+		// these funds will still get slashed.
+		assert_ok!(Pools::unbond(Origin::signed(10), 10, 10));
+		assert_ok!(Pools::unbond(Origin::signed(20), 20, 10));
+		assert_ok!(Pools::unbond(Origin::signed(21), 21, 10));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+				StakingEvent::Unbonded(POOL1_BONDED, 10),
+			]
+		);
+
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Unbonded { member: 10, pool_id: 1, balance: 10, points: 10 },
+				PoolsEvent::Unbonded { member: 20, pool_id: 1, balance: 10, points: 10 },
+				PoolsEvent::Unbonded { member: 21, pool_id: 1, balance: 10, points: 10 },
+			]
+		);
+
+		// At this point, 20 are safe from slash, 30 are unlocking but vulnerable to slash, and and
+		// another 30 are active and vulnerable to slash. Let's slash half of them.
+		pallet_staking::slashing::do_slash::<Runtime>(
+			&POOL1_BONDED,
+			30,
+			&mut Default::default(),
+			&mut Default::default(),
+			1, // slash era 1, affects chunks at era 5 onwards.
+		);
+
+		assert_eq!(staking_events_since_last_call(), vec![StakingEvent::Slashed(POOL1_BONDED, 30)]);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				// 30 has been slashed to 15 (15 slash)
+				PoolsEvent::UnbondingPoolSlashed { pool_id: 1, era: 5, balance: 15 },
+				// 30 has been slashed to 15 (15 slash)
+				PoolsEvent::PoolSlashed { pool_id: 1, balance: 15 }
+			]
+		);
+
+		CurrentEra::<Runtime>::set(Some(3));
+		assert_ok!(Pools::unbond(Origin::signed(21), 21, 10));
+
+		assert_eq!(
+			PoolMembers::<Runtime>::get(21).unwrap(),
+			PoolMember {
+				pool_id: 1,
+				points: 0,
+				reward_pool_total_earnings: 0,
+				// the 10 points unlocked just now correspond to 5 points in the unbond pool.
+				unbonding_eras: bounded_btree_map!(5 => 10, 6 => 5)
+			}
+		);
+		assert_eq!(staking_events_since_last_call(), vec![StakingEvent::Unbonded(POOL1_BONDED, 5)]);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![PoolsEvent::Unbonded { member: 21, pool_id: 1, balance: 5, points: 5 }]
+		);
+
+		// now we start withdrawing. we do it all at once, at era 6 where 20 and 21 are fully free.
+		CurrentEra::<Runtime>::set(Some(6));
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(20), 20, 0));
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(21), 21, 0));
+
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				// 20 had unbonded 10 safely, and 10 got slashed by half.
+				PoolsEvent::Withdrawn { member: 20, pool_id: 1, balance: 10 + 5, points: 20 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 20 },
+				// 21 unbonded all of it after the slash
+				PoolsEvent::Withdrawn { member: 21, pool_id: 1, balance: 5 + 5, points: 15 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 21 }
+			]
+		);
+		assert_eq!(
+			staking_events_since_last_call(),
+			// a 10 (un-slashed) + 10/2 (slashed) balance from 10 has also been unlocked
+			vec![StakingEvent::Withdrawn(POOL1_BONDED, 15 + 10 + 15)]
+		);
+
+		// now, finally, we can unbond the depositor further than their current limit.
+		assert_ok!(Pools::set_state(Origin::signed(10), 1, PoolState::Destroying));
+		assert_ok!(Pools::unbond(Origin::signed(10), 10, 20));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Unbonded(POOL1_BONDED, 10)]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::StateChanged { pool_id: 1, new_state: PoolState::Destroying },
+				PoolsEvent::Unbonded { member: 10, pool_id: 1, points: 10, balance: 10 }
+			]
+		);
+
+		CurrentEra::<Runtime>::set(Some(9));
+		assert_eq!(
+			PoolMembers::<Runtime>::get(10).unwrap(),
+			PoolMember {
+				pool_id: 1,
+				points: 0,
+				reward_pool_total_earnings: 0,
+				unbonding_eras: bounded_btree_map!(4 => 10, 5 => 10, 9 => 10)
+			}
+		);
+		// withdraw the depositor, they should lose 12 balance in total due to slash.
+		assert_ok!(Pools::withdraw_unbonded(Origin::signed(10), 10, 0));
+
+		assert_eq!(
+			staking_events_since_last_call(),
+			vec![StakingEvent::Withdrawn(POOL1_BONDED, 10)]
+		);
+		assert_eq!(
+			pool_events_since_last_call(),
+			vec![
+				PoolsEvent::Withdrawn { member: 10, pool_id: 1, balance: 10 + 15, points: 30 },
+				PoolsEvent::MemberRemoved { pool_id: 1, member: 10 },
+				PoolsEvent::Destroyed { pool_id: 1 }
+			]
+		);
+	});
+}
@@ -0,0 +1,261 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use frame_election_provider_support::VoteWeight;
+use frame_support::{assert_ok, pallet_prelude::*, parameter_types, traits::ConstU64, PalletId};
+use sp_runtime::traits::{Convert, IdentityLookup};
+
+type AccountId = u128;
+type AccountIndex = u32;
+type BlockNumber = u64;
+type Balance = u128;
+
+pub(crate) const POOL1_BONDED: AccountId = 20318131474730217858575332831085u128;
+pub(crate) const POOL1_REWARD: AccountId = 20397359637244482196168876781421u128;
+
+impl frame_system::Config for Runtime {
+	type BaseCallFilter = frame_support::traits::Everything;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type Origin = Origin;
+	type Index = AccountIndex;
+	type BlockNumber = BlockNumber;
+	type Call = Call;
+	type Hash = sp_core::H256;
+	type Hashing = sp_runtime::traits::BlakeTwo256;
+	type AccountId = AccountId;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type Header = sp_runtime::testing::Header;
+	type Event = Event;
+	type BlockHashCount = ();
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = pallet_balances::AccountData<Balance>;
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = frame_support::traits::ConstU32<16>;
+}
+
+impl pallet_timestamp::Config for Runtime {
+	type Moment = u64;
+	type OnTimestampSet = ();
+	type MinimumPeriod = ConstU64<5>;
+	type WeightInfo = ();
+}
+
+parameter_types! {
+	pub static ExistentialDeposit: Balance = 5;
+}
+
+impl pallet_balances::Config for Runtime {
+	type MaxLocks = ();
+	type MaxReserves = ();
+	type ReserveIdentifier = [u8; 8];
+	type Balance = Balance;
+	type Event = Event;
+	type DustRemoval = ();
+	type ExistentialDeposit = ExistentialDeposit;
+	type AccountStore = System;
+	type WeightInfo = ();
+}
+
+pallet_staking_reward_curve::build! {
+	const I_NPOS: sp_runtime::curve::PiecewiseLinear<'static> = curve!(
+		min_inflation: 0_025_000,
+		max_inflation: 0_100_000,
+		ideal_stake: 0_500_000,
+		falloff: 0_050_000,
+		max_piece_count: 40,
+		test_precision: 0_005_000,
+	);
+}
+
+parameter_types! {
+	pub const RewardCurve: &'static sp_runtime::curve::PiecewiseLinear<'static> = &I_NPOS;
+	pub static BondingDuration: u32 = 3;
+}
+
+impl pallet_staking::Config for Runtime {
+	type MaxNominations = ConstU32<16>;
+	type Currency = Balances;
+	type CurrencyBalance = Balance;
+	type UnixTime = pallet_timestamp::Pallet<Self>;
+	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type RewardRemainder = ();
+	type Event = Event;
+	type Slash = ();
+	type Reward = ();
+	type SessionsPerEra = ();
+	type SlashDeferDuration = ();
+	type SlashCancelOrigin = frame_system::EnsureRoot<Self::AccountId>;
+	type BondingDuration = BondingDuration;
+	type SessionInterface = ();
+	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
+	type NextNewSession = ();
+	type MaxNominatorRewardedPerValidator = ConstU32<64>;
+	type OffendingValidatorsThreshold = ();
+	type ElectionProvider =
+		frame_election_provider_support::NoElection<(AccountId, BlockNumber, Staking)>;
+	type GenesisElectionProvider = Self::ElectionProvider;
+	type VoterList = pallet_bags_list::Pallet<Self>;
+	type MaxUnlockingChunks = ConstU32<32>;
+	type OnStakerSlash = Pools;
+	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
+	type WeightInfo = ();
+}
+
+parameter_types! {
+	pub static BagThresholds: &'static [VoteWeight] = &[10, 20, 30, 40, 50, 60, 1_000, 2_000, 10_000];
+}
+
+impl pallet_bags_list::Config for Runtime {
+	type Event = Event;
+	type WeightInfo = ();
+	type BagThresholds = BagThresholds;
+	type ScoreProvider = Staking;
+	type Score = VoteWeight;
+}
+
+pub struct BalanceToU256;
+impl Convert<Balance, sp_core::U256> for BalanceToU256 {
+	fn convert(n: Balance) -> sp_core::U256 {
+		n.into()
+	}
+}
+
+pub struct U256ToBalance;
+impl Convert<sp_core::U256, Balance> for U256ToBalance {
+	fn convert(n: sp_core::U256) -> Balance {
+		n.try_into().unwrap()
+	}
+}
+
+parameter_types! {
+	pub const PostUnbondingPoolsWindow: u32 = 10;
+	pub const PoolsPalletId: PalletId = PalletId(*b"py/nopls");
+}
+
+impl pallet_nomination_pools::Config for Runtime {
+	type Event = Event;
+	type WeightInfo = ();
+	type Currency = Balances;
+	type BalanceToU256 = BalanceToU256;
+	type U256ToBalance = U256ToBalance;
+	type StakingInterface = Staking;
+	type PostUnbondingPoolsWindow = PostUnbondingPoolsWindow;
+	type MaxMetadataLen = ConstU32<256>;
+	type MaxUnbonding = ConstU32<8>;
+	type MinPointsToBalance = ConstU32<10>;
+	type PalletId = PoolsPalletId;
+}
+
+impl<LocalCall> frame_system::offchain::SendTransactionTypes<LocalCall> for Runtime
+where
+	Call: From<LocalCall>,
+{
+	type OverarchingCall = Call;
+	type Extrinsic = UncheckedExtrinsic;
+}
+
+type Block = frame_system::mocking::MockBlock<Runtime>;
+type UncheckedExtrinsic = frame_system::mocking::MockUncheckedExtrinsic<Runtime>;
+
+frame_support::construct_runtime!(
+	pub enum Runtime where
+		Block = Block,
+		NodeBlock = Block,
+		UncheckedExtrinsic = UncheckedExtrinsic
+	{
+		System: frame_system::{Pallet, Call, Event<T>},
+		Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},
+		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
+		Staking: pallet_staking::{Pallet, Call, Config<T>, Storage, Event<T>},
+		BagsList: pallet_bags_list::{Pallet, Call, Storage, Event<T>},
+		Pools: pallet_nomination_pools::{Pallet, Call, Storage, Event<T>},
+	}
+);
+
+pub fn new_test_ext() -> sp_io::TestExternalities {
+	let mut storage = frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap();
+	let _ = pallet_nomination_pools::GenesisConfig::<Runtime> {
+		min_join_bond: 2,
+		min_create_bond: 2,
+		max_pools: Some(3),
+		max_members_per_pool: Some(3),
+		max_members: Some(3 * 3),
+	}
+	.assimilate_storage(&mut storage)
+	.unwrap();
+
+	let _ = pallet_balances::GenesisConfig::<Runtime> {
+		balances: vec![(10, 100), (20, 100), (21, 100), (22, 100)],
+	}
+	.assimilate_storage(&mut storage)
+	.unwrap();
+
+	let mut ext = sp_io::TestExternalities::from(storage);
+
+	ext.execute_with(|| {
+		// for events to be deposited.
+		frame_system::Pallet::<Runtime>::set_block_number(1);
+
+		// set some limit for nominations.
+		assert_ok!(Staking::set_staking_configs(
+			Origin::root(),
+			pallet_staking::ConfigOp::Set(10), // minimum nominator bond
+			pallet_staking::ConfigOp::Noop,
+			pallet_staking::ConfigOp::Noop,
+			pallet_staking::ConfigOp::Noop,
+			pallet_staking::ConfigOp::Noop,
+			pallet_staking::ConfigOp::Noop,
+		));
+	});
+
+	ext
+}
+
+parameter_types! {
+	static ObservedEventsPools: usize = 0;
+	static ObservedEventsStaking: usize = 0;
+	static ObservedEventsBalances: usize = 0;
+}
+
+pub(crate) fn pool_events_since_last_call() -> Vec<pallet_nomination_pools::Event<Runtime>> {
+	let events = System::events()
+		.into_iter()
+		.map(|r| r.event)
+		.filter_map(|e| if let Event::Pools(inner) = e { Some(inner) } else { None })
+		.collect::<Vec<_>>();
+	let already_seen = ObservedEventsPools::get();
+	ObservedEventsPools::set(events.len());
+	events.into_iter().skip(already_seen).collect()
+}
+
+pub(crate) fn staking_events_since_last_call() -> Vec<pallet_staking::Event<Runtime>> {
+	let events = System::events()
+		.into_iter()
+		.map(|r| r.event)
+		.filter_map(|e| if let Event::Staking(inner) = e { Some(inner) } else { None })
+		.collect::<Vec<_>>();
+	let already_seen = ObservedEventsStaking::get();
+	ObservedEventsStaking::set(events.len());
+	events.into_iter().skip(already_seen).collect()
+}