Default Config for Staking

substrate/frame/babe/src/mock.rs

@@ -24,7 +24,7 @@ use frame_election_provider_support::{
 	onchain, SequentialPhragmen,
 };
 use frame_support::{
-	parameter_types,
+	derive_impl, parameter_types,
 	traits::{ConstU128, ConstU32, ConstU64, KeyOwnerProofSystem, OnInitialize},
 };
 use pallet_session::historical as pallet_session_historical;
@@ -63,30 +63,17 @@ frame_support::construct_runtime!(
 	}
 );
 
+#[derive_impl(frame_system::config_preludes::TestDefaultConfig as frame_system::DefaultConfig)]
 impl frame_system::Config for Test {
 	type BaseCallFilter = frame_support::traits::Everything;
-	type BlockWeights = ();
-	type BlockLength = ();
-	type DbWeight = ();
 	type RuntimeOrigin = RuntimeOrigin;
 	type Nonce = u64;
 	type RuntimeCall = RuntimeCall;
-	type Hash = H256;
-	type Version = ();
-	type Hashing = sp_runtime::traits::BlakeTwo256;
-	type AccountId = DummyValidatorId;
-	type Lookup = IdentityLookup<Self::AccountId>;
 	type Block = Block;
 	type RuntimeEvent = RuntimeEvent;
 	type BlockHashCount = ConstU64<250>;
-	type PalletInfo = PalletInfo;
-	type AccountData = pallet_balances::AccountData<u128>;
-	type OnNewAccount = ();
-	type OnKilledAccount = ();
-	type SystemWeightInfo = ();
-	type SS58Prefix = ();
+	type AccountData = pallet_balances::AccountData<u64>;
 	type OnSetCode = ();
-	type MaxConsumers = frame_support::traits::ConstU32<16>;
 }
 
 impl<C> frame_system::offchain::SendTransactionTypes<C> for Test
@@ -116,7 +103,7 @@ impl pallet_session::Config for Test {
 }
 
 impl pallet_session::historical::Config for Test {
-	type FullIdentification = pallet_staking::Exposure<u64, u128>;
+	type FullIdentification = pallet_staking::Exposure<u64, u64>;
 	type FullIdentificationOf = pallet_staking::ExposureOf<Self>;
 }
 
@@ -132,20 +119,14 @@ impl pallet_timestamp::Config for Test {
 	type WeightInfo = ();
 }
 
+#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig as pallet_balances::DefaultConfig)]
 impl pallet_balances::Config for Test {
-	type MaxLocks = ();
-	type MaxReserves = ();
 	type ReserveIdentifier = [u8; 8];
-	type Balance = u128;
 	type DustRemoval = ();
 	type RuntimeEvent = RuntimeEvent;
-	type ExistentialDeposit = ConstU128<1>;
+	type ExistentialDeposit = ConstU64<1>;
 	type AccountStore = System;
-	type WeightInfo = ();
-	type FreezeIdentifier = ();
-	type MaxFreezes = ();
 	type RuntimeHoldReason = ();
-	type MaxHolds = ();
 }
 
 pallet_staking_reward_curve::build! {
@@ -177,35 +158,28 @@ impl onchain::Config for OnChainSeqPhragmen {
 	type MaxWinners = ConstU32<100>;
 	type Bounds = ElectionsBounds;
 }
-
+#[derive_impl(pallet_staking::config_preludes::TestDefaultConfig as pallet_staking::DefaultConfig)]
 impl pallet_staking::Config for Test {
 	type RewardRemainder = ();
 	type CurrencyToVote = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Currency = Balances;
-	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
 	type Slash = ();
 	type Reward = ();
-	type SessionsPerEra = SessionsPerEra;
-	type BondingDuration = BondingDuration;
 	type SlashDeferDuration = SlashDeferDuration;
 	type AdminOrigin = frame_system::EnsureRoot<Self::AccountId>;
 	type SessionInterface = Self;
 	type UnixTime = pallet_timestamp::Pallet<Test>;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
-	type MaxNominatorRewardedPerValidator = ConstU32<64>;
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	type NextNewSession = Session;
 	type ElectionProvider = onchain::OnChainExecution<OnChainSeqPhragmen>;
 	type GenesisElectionProvider = Self::ElectionProvider;
 	type VoterList = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type NominationsQuota = FixedNominationsQuota<16>;
-	type MaxUnlockingChunks = ConstU32<32>;
-	type HistoryDepth = ConstU32<84>;
 	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
-	type WeightInfo = ();
 }
 
 impl pallet_offences::Config for Test {

substrate/frame/staking/src/pallet/mod.rs

@@ -82,9 +82,36 @@ pub mod pallet {
 		Remove,
 	}
 
-	#[pallet::config]
+	/// Some default provided implementations of [`DefaultConfig`], which can be used to implement
+	/// [`Config`] in the runtime.
+	pub mod config_preludes {
+		use super::*;
+		use frame_support::derive_impl;
+
+		/// Provides a simple default config of staking pallet to derive a testing pallet config in
+		/// mocked runtimes.
+		pub struct TestDefaultConfig;
+
+		#[derive_impl(frame_system::config_preludes::TestDefaultConfig as frame_system::DefaultConfig, no_aggregated_types)]
+		impl frame_system::DefaultConfig for TestDefaultConfig {}
+
+		#[frame_support::register_default_impl(TestDefaultConfig)]
+		impl DefaultConfig for TestDefaultConfig {
+			type CurrencyBalance = u64;
+			type SessionsPerEra = ConstU32<3>;
+			type BondingDuration = ConstU32<3>;
+			type SlashDeferDuration = ConstU32<0>;
+			type MaxNominatorRewardedPerValidator = ConstU32<64>;
+			type MaxUnlockingChunks = ConstU32<32>;
+			type HistoryDepth = ConstU32<84>;
+			type WeightInfo = ();
+		}
+	}
+
+	#[pallet::config(with_default)]
 	pub trait Config: frame_system::Config {
 		/// The staking balance.
+		#[pallet::no_default]
 		type Currency: LockableCurrency<
 			Self::AccountId,
 			Moment = BlockNumberFor<Self>,
@@ -101,10 +128,12 @@ pub mod pallet {
 			+ From<u64>
 			+ TypeInfo
 			+ MaxEncodedLen;
+
 		/// Time used for computing era duration.
 		///
 		/// It is guaranteed to start being called from the first `on_finalize`. Thus value at
 		/// genesis is not used.
+		#[pallet::no_default]
 		type UnixTime: UnixTime;
 
 		/// Convert a balance into a number used for election calculation. This must fit into a
@@ -113,23 +142,27 @@ pub mod pallet {
 		/// in 128.
 		/// Consequently, the backward convert is used convert the u128s from sp-elections back to a
 		/// [`BalanceOf`].
+		#[pallet::no_default]
 		type CurrencyToVote: sp_staking::currency_to_vote::CurrencyToVote<BalanceOf<Self>>;
 
 		/// Something that provides the election functionality.
+		#[pallet::no_default]
 		type ElectionProvider: ElectionProvider<
 			AccountId = Self::AccountId,
 			BlockNumber = BlockNumberFor<Self>,
 			// we only accept an election provider that has staking as data provider.
 			DataProvider = Pallet<Self>,
 		>;
 		/// Something that provides the election functionality at genesis.
+		#[pallet::no_default]
 		type GenesisElectionProvider: ElectionProvider<
 			AccountId = Self::AccountId,
 			BlockNumber = BlockNumberFor<Self>,
 			DataProvider = Pallet<Self>,
 		>;
 
 		/// Something that defines the maximum number of nominations per nominator.
+		#[pallet::no_default]
 		type NominationsQuota: NominationsQuota<BalanceOf<Self>>;
 
 		/// Number of eras to keep in history.
@@ -157,17 +190,21 @@ pub mod pallet {
 
 		/// Tokens have been minted and are unused for validator-reward.
 		/// See [Era payout](./index.html#era-payout).
+		#[pallet::no_default]
 		type RewardRemainder: OnUnbalanced<NegativeImbalanceOf<Self>>;
 
 		/// The overarching event type.
+		#[pallet::no_default]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Handler for the unbalanced reduction when slashing a staker.
+		#[pallet::no_default]
 		type Slash: OnUnbalanced<NegativeImbalanceOf<Self>>;
 
 		/// Handler for the unbalanced increment when rewarding a staker.
 		/// NOTE: in most cases, the implementation of `OnUnbalanced` should modify the total
 		/// issuance.
+		#[pallet::no_default]
 		type Reward: OnUnbalanced<PositiveImbalanceOf<Self>>;
 
 		/// Number of sessions per era.
@@ -188,17 +225,21 @@ pub mod pallet {
 		/// The origin which can manage less critical staking parameters that does not require root.
 		///
 		/// Supported actions: (1) cancel deferred slash, (2) set minimum commission.
+		#[pallet::no_default]
 		type AdminOrigin: EnsureOrigin<Self::RuntimeOrigin>;
 
 		/// Interface for interacting with a session pallet.
+		#[pallet::no_default]
 		type SessionInterface: SessionInterface<Self::AccountId>;
 
 		/// The payout for validators and the system for the current era.
 		/// See [Era payout](./index.html#era-payout).
+		#[pallet::no_default]
 		type EraPayout: EraPayout<BalanceOf<Self>>;
 
 		/// Something that can estimate the next session change, accurately or as a best effort
 		/// guess.
+		#[pallet::no_default]
 		type NextNewSession: EstimateNextNewSession<BlockNumberFor<Self>>;
 
 		/// The maximum number of nominators rewarded for each validator.
@@ -210,6 +251,7 @@ pub mod pallet {
 
 		/// The fraction of the validator set that is safe to be offending.
 		/// After the threshold is reached a new era will be forced.
+		#[pallet::no_default]
 		type OffendingValidatorsThreshold: Get<Perbill>;
 
 		/// Something that provides a best-effort sorted list of voters aka electing nominators,
@@ -223,6 +265,7 @@ pub mod pallet {
 		/// staker. In case of `bags-list`, this always means using `rebag` and `putInFrontOf`.
 		///
 		/// Invariant: what comes out of this list will always be a nominator.
+		#[pallet::no_default]
 		type VoterList: SortedListProvider<Self::AccountId, Score = VoteWeight>;
 
 		/// WIP: This is a noop as of now, the actual business logic that's described below is going
@@ -245,6 +288,7 @@ pub mod pallet {
 		/// validators, they can chill at any point, and their approval stakes will still be
 		/// recorded. This implies that what comes out of iterating this list MIGHT NOT BE AN ACTIVE
 		/// VALIDATOR.
+		#[pallet::no_default]
 		type TargetList: SortedListProvider<Self::AccountId, Score = BalanceOf<Self>>;
 
 		/// The maximum number of `unlocking` chunks a [`StakingLedger`] can
@@ -264,9 +308,11 @@ pub mod pallet {
 		/// receives.
 		///
 		/// WARNING: this only reports slashing events for the time being.
+		#[pallet::no_default]
 		type EventListeners: sp_staking::OnStakingUpdate<Self::AccountId, BalanceOf<Self>>;
 
 		/// Some parameters of the benchmarking.
+		#[pallet::no_default]
 		type BenchmarkingConfig: BenchmarkingConfig;
 
 		/// Weight information for extrinsics in this pallet.

substrate/frame/support/procedural/src/lib.rs

@@ -554,9 +554,10 @@ pub fn storage_alias(attributes: TokenStream, input: TokenStream) -> TokenStream
 }
 
 /// This attribute can be used to derive a full implementation of a trait based on a local partial
-/// impl and an external impl containing defaults that can be overriden in the local impl.
+/// impl and an external impl containing defaults that can be overridden in the local impl.
 ///
-/// For a full end-to-end example, see [below](#use-case-auto-derive-test-pallet-config-traits).
+/// For a full end-to-end example, see
+/// [below](#use-case-example-auto-derive-test-pallet-config-traits).
 ///
 /// # Usage
 ///