Stake tracker improvements (migration and try-state checks OK in Polk…

…adot) (#4673)

Changes in the migration code introduced in this PR:
- Migration removes duplicate nominations in all nominators, if they
exist (changes by calling `fn do_add_nominator` with dedup nominations)
- Migration removes all the non active validator nominations to avoid
adding dangling nominations (changes by calling `fn do_add_nominator` if
necessary)
- Migration iterates through all `Nominators` map first and through all
the `Validators` map to insert all the validators that are not nominated
to the target list (with self-stake only).
- Moves stake-tracker related try-state checks to the staking pallet (no
try-state checks in the stake-tracker pallet anymore).
- Runs benchmarks for MMB migration step with bench bot. 

The migration code has been validated against the Polkadot using the
externalities tests in
[polkadot/runtime/westend/src/lib.rs](https://github.com/paritytech/polkadot-sdk/pull/4436/files/46a80f14ba8990b014d8f9df36727c77e2f3e929#diff-5264d812f7aadfc486efffd3322b11c8dee5e8ddf2e77e0a9e70b573f3d2afdd).
Upon running the migrations, we ensure that:
- All validators have been added to the target list with their correct
approvals score (as per the try-state checks).
- All nominations are "cleaned" (see def. of clean above)
- Try-state checks related to stake-tracker and approvals pass.

Note: Same as #4436 but
with a non-messed up git history. Merging into
`gpestana/stake-tracker_integration`.

---------

Co-authored-by: Ankan <ankan.anurag@gmail.com>
Co-authored-by: command-bot <>

polkadot/runtime/westend/src/lib.rs

@@ -583,7 +583,7 @@ parameter_types! {
 	pub const VoterBagThresholds: &'static [u64] = &bag_thresholds::VOTER_THRESHOLDS;
 	pub const TargetBagThresholds: &'static [u128] = &bag_thresholds::TARGET_THRESHOLDS;
 
-	pub const VoterUpdateMode: pallet_stake_tracker::VoterUpdateMode = pallet_stake_tracker::VoterUpdateMode::Strict;
+	pub const VoterUpdateMode: pallet_stake_tracker::VoterUpdateMode = pallet_stake_tracker::VoterUpdateMode::Lazy;
 }
 
 type VoterBagsListInstance = pallet_bags_list::Instance1;
@@ -1685,8 +1685,7 @@ pub mod migrations {
 	}
 
 	/// Unreleased migrations. Add new ones here:
-	pub type Unreleased =
-		(pallet_staking::migrations::single_block::v15::MigrateV14ToV15<Runtime>,);
+	pub type Unreleased = ();
 }
 
 /// Unchecked extrinsic type as expected by this runtime.

substrate/bin/node/runtime/src/lib.rs

@@ -704,7 +704,7 @@ impl pallet_staking::Config for Runtime {
 }
 
 parameter_types! {
-	pub const VoterUpdateMode: pallet_stake_tracker::VoterUpdateMode = pallet_stake_tracker::VoterUpdateMode::Strict;
+	pub const VoterUpdateMode: pallet_stake_tracker::VoterUpdateMode = pallet_stake_tracker::VoterUpdateMode::Lazy;
 }
 
 impl pallet_stake_tracker::Config for Runtime {

substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs

@@ -263,7 +263,7 @@ impl pallet_bags_list::Config<TargetBagsListInstance> for Runtime {
 }
 
 parameter_types! {
-	pub static UpdateMode: VoterUpdateMode = VoterUpdateMode::Strict;
+	pub static UpdateMode: VoterUpdateMode = VoterUpdateMode::Lazy;
 }
 
 impl pallet_stake_tracker::Config for Runtime {

substrate/frame/staking/Cargo.toml

@@ -31,6 +31,7 @@ pallet-session = { path = "../session", default-features = false, features = [
 	"historical",
 ] }
 pallet-authorship = { path = "../authorship", default-features = false }
+pallet-stake-tracker = { path = "./stake-tracker", default-features = false }
 sp-application-crypto = { path = "../../primitives/application-crypto", default-features = false, features = ["serde"] }
 frame-election-provider-support = { path = "../election-provider-support", default-features = false }
 log = { workspace = true }
@@ -45,9 +46,8 @@ sp-tracing = { path = "../../primitives/tracing" }
 sp-core = { path = "../../primitives/core" }
 sp-npos-elections = { path = "../../primitives/npos-elections" }
 pallet-timestamp = { path = "../timestamp" }
-pallet-stake-tracker = { path = "./stake-tracker" }
 pallet-staking-reward-curve = { path = "reward-curve" }
-pallet-bags-list = { path = "../bags-list" }
+pallet-bags-list = { path = "../bags-list", default-features = false, features = ["try-runtime"] }
 pallet-migrations = { path = "../migrations" }
 substrate-test-utils = { path = "../../test-utils" }
 frame-benchmarking = { path = "../benchmarking" }

substrate/frame/staking/src/benchmarking.rs

@@ -1145,7 +1145,7 @@ mod benchmarks {
 
 		assert_eq!(
 			Staking::<T>::status(&voter),
-			Ok(StakerStatus::Nominator(vec![dangling_target.clone(), other_target.clone()]))
+			Ok(StakerStatus::Nominator(vec![other_target.clone(), dangling_target.clone()]))
 		);
 
 		#[extrinsic_call]
@@ -1214,7 +1214,7 @@ mod benchmarks {
 
 	impl_benchmark_test_suite!(
 		Staking,
-		crate::mock::ExtBuilder::default().has_stakers(true).set_voter_list_lazy(),
+		crate::mock::ExtBuilder::default().has_stakers(true),
 		crate::mock::Test,
 		exec_name = build_and_execute
 	);
@@ -1228,7 +1228,7 @@ mod tests {
 
 	#[test]
 	fn create_validators_with_nominators_for_era_works() {
-		ExtBuilder::default().build_and_execute(|| {
+		ExtBuilder::default().try_state(false).build_and_execute(|| {
 			let v = 10;
 			let n = 100;
 
@@ -1254,7 +1254,7 @@ mod tests {
 
 	#[test]
 	fn create_validator_with_nominators_works() {
-		ExtBuilder::default().build_and_execute(|| {
+		ExtBuilder::default().try_state(false).build_and_execute(|| {
 			let n = 10;
 
 			let (validator_stash, nominators) = create_validator_with_nominators::<Test>(
@@ -1285,7 +1285,7 @@ mod tests {
 
 	#[test]
 	fn add_slashing_spans_works() {
-		ExtBuilder::default().build_and_execute(|| {
+		ExtBuilder::default().try_state(false).build_and_execute(|| {
 			let n = 10;
 
 			let (validator_stash, _nominators) = create_validator_with_nominators::<Test>(
@@ -1315,28 +1315,4 @@ mod tests {
 			}
 		});
 	}
-
-	// TODO: SelectedBenchmark not exposed by v2?
-	/*
-	#[test]
-	fn test_payout_all() {
-		ExtBuilder::default().build_and_execute(|| {
-			let v = 10;
-			let n = 100;
-
-			let selected_benchmark = SelectedBenchmark::payout_all;
-			let c = vec![
-				(frame_benchmarking::BenchmarkParameter::v, v),
-				(frame_benchmarking::BenchmarkParameter::n, n),
-			];
-
-			assert_ok!(
-				<SelectedBenchmark as frame_benchmarking::BenchmarkingSetup<Test>>::unit_test_instance(
-					&selected_benchmark,
-					&c,
-				)
-			);
-		});
-	}
-	*/
 }