[Staking] Currency <> Fungible migration

polkadot/runtime/test-runtime/src/lib.rs

@@ -367,11 +367,13 @@ impl onchain::Config for OnChainSeqPhragmen {
 const MAX_QUOTA_NOMINATIONS: u32 = 16;
 
 impl pallet_staking::Config for Runtime {
+	type OldCurrency = Balances;
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = polkadot_runtime_common::CurrencyToVote;
 	type RewardRemainder = ();
+	type RuntimeHoldReason = RuntimeHoldReason;
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
 	type Reward = ();

polkadot/runtime/westend/src/lib.rs

@@ -723,8 +723,10 @@ parameter_types! {
 }
 
 impl pallet_staking::Config for Runtime {
+	type OldCurrency = Balances;
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
+	type RuntimeHoldReason = RuntimeHoldReason;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = CurrencyToVote;
 	type RewardRemainder = ();

polkadot/runtime/westend/src/tests.rs

@@ -155,25 +155,27 @@ mod remote_tests {
 
 		let transport: Transport = var("WS").unwrap_or("ws://127.0.0.1:9900".to_string()).into();
 		let maybe_state_snapshot: Option<SnapshotConfig> = var("SNAP").map(|s| s.into()).ok();
+		let online_config = OnlineConfig {
+			transport,
+			state_snapshot: maybe_state_snapshot.clone(),
+			child_trie: false,
+			pallets: vec![
+				"Staking".into(),
+				"System".into(),
+				"Balances".into(),
+				"NominationPools".into(),
+				"DelegatedStaking".into(),
+			],
+			..Default::default()
+		};
 		let mut ext = Builder::<Block>::default()
 			.mode(if let Some(state_snapshot) = maybe_state_snapshot {
 				Mode::OfflineOrElseOnline(
 					OfflineConfig { state_snapshot: state_snapshot.clone() },
-					OnlineConfig {
-						transport,
-						state_snapshot: Some(state_snapshot),
-						pallets: vec![
-							"staking".into(),
-							"system".into(),
-							"balances".into(),
-							"nomination-pools".into(),
-							"delegated-staking".into(),
-						],
-						..Default::default()
-					},
+					online_config,
 				)
 			} else {
-				Mode::Online(OnlineConfig { transport, ..Default::default() })
+				Mode::Online(online_config)
 			})
 			.build()
 			.await
@@ -241,6 +243,77 @@ mod remote_tests {
 			);
 		});
 	}
+
+	#[tokio::test]
+	async fn staking_curr_fun_migrate() {
+		// Intended to be run only manually.
+		if var("RUN_MIGRATION_TESTS").is_err() {
+			return;
+		}
+		sp_tracing::try_init_simple();
+
+		let transport: Transport = var("WS").unwrap_or("ws://127.0.0.1:9900".to_string()).into();
+		let maybe_state_snapshot: Option<SnapshotConfig> = var("SNAP").map(|s| s.into()).ok();
+		let online_config = OnlineConfig {
+			transport,
+			state_snapshot: maybe_state_snapshot.clone(),
+			child_trie: false,
+			pallets: vec!["Staking".into(), "System".into(), "Balances".into()],
+			..Default::default()
+		};
+		let mut ext = Builder::<Block>::default()
+			.mode(if let Some(state_snapshot) = maybe_state_snapshot {
+				Mode::OfflineOrElseOnline(
+					OfflineConfig { state_snapshot: state_snapshot.clone() },
+					online_config,
+				)
+			} else {
+				Mode::Online(online_config)
+			})
+			.build()
+			.await
+			.unwrap();
+		ext.execute_with(|| {
+			// create an account with some balance
+			let alice = AccountId::from([1u8; 32]);
+			use frame_support::traits::Currency;
+			let _ = Balances::deposit_creating(&alice, 100_000 * UNITS);
+
+			let mut success = 0;
+			let mut err = 0;
+			let mut force_withdraw_acc = 0;
+			// iterate over all pools
+			pallet_staking::Ledger::<Runtime>::iter().for_each(|(ctrl, ledger)| {
+				match pallet_staking::Pallet::<Runtime>::migrate_currency(
+					RuntimeOrigin::signed(alice.clone()).into(),
+					ledger.stash.clone(),
+				) {
+					Ok(_) => {
+						let updated_ledger =
+							pallet_staking::Ledger::<Runtime>::get(&ctrl).expect("ledger exists");
+						let force_withdraw = ledger.total - updated_ledger.total;
+						if force_withdraw > 0 {
+							force_withdraw_acc += force_withdraw;
+							log::info!(target: "remote_test", "Force withdraw from stash {:?}: value {:?}", ledger.stash, force_withdraw);
+						}
+						success += 1;
+					},
+					Err(e) => {
+						log::error!(target: "remote_test", "Error migrating {:?}: {:?}", ledger.stash, e);
+						err += 1;
+					},
+				}
+			});
+
+			log::info!(
+				target: "remote_test",
+				"Migration stats: success: {}, err: {}, total force withdrawn stake: {}",
+				success,
+				err,
+				force_withdraw_acc
+			);
+		});
+	}
 }
 
 #[test]