From 5c1452917a195413ce28137ef9176937865e72da Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 13:13:05 +0200
Subject: [PATCH 01/42] move migrate sequence to config

---
 bin/node/runtime/src/lib.rs             |  4 +++-
 frame/contracts/src/benchmarking/mod.rs | 10 ++++-----
 frame/contracts/src/lib.rs              | 29 ++++++++++++++-----------
 frame/contracts/src/migration.rs        | 25 +++++++--------------
 frame/contracts/src/tests.rs            |  5 +++--
 5 files changed, 35 insertions(+), 38 deletions(-)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index 6dc9841f6b44f..33ffe6d4f32cc 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -55,6 +55,7 @@ use frame_system::{
 pub use node_primitives::{AccountId, Signature};
 use node_primitives::{AccountIndex, Balance, BlockNumber, Hash, Index, Moment};
 use pallet_asset_conversion::{NativeOrAssetId, NativeOrAssetIdConverter};
+use pallet_contracts::migration::{v10, v11, v9};
 use pallet_election_provider_multi_phase::SolutionAccuracyOf;
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
 use pallet_nfts::PalletFeatures;
@@ -1240,6 +1241,7 @@ impl pallet_contracts::Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<false>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+	type Migrations = (v9::Migration<Runtime>, v10::Migration<Runtime>, v11::Migration<Runtime>);
 }
 
 impl pallet_sudo::Config for Runtime {
@@ -1981,7 +1983,7 @@ pub type Executive = frame_executive::Executive<
 type Migrations = (
 	pallet_nomination_pools::migration::v2::MigrateToV2<Runtime>,
 	pallet_alliance::migration::Migration<Runtime>,
-	pallet_contracts::Migration<Runtime>,
+	pallet_contracts::Migration<Runtime, <Runtime as pallet_contracts::Config>::Migrations>,
 );
 
 type EventRecord = frame_system::EventRecord<
diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index b98c05f2503c2..27b9aadeed675 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -272,7 +272,7 @@ benchmarks! {
 	migration_noop {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}:  {
-		Migration::<T>::migrate(Weight::MAX)
+		Migration::<T, T::Migrations>::migrate(Weight::MAX)
 	} verify {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
@@ -281,7 +281,7 @@ benchmarks! {
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();
-		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade();
+		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade();
 		let origin: RawOrigin<<T as frame_system::Config>::AccountId> = RawOrigin::Signed(whitelisted_caller());
 	}: {
 		<Contracts<T>>::migrate(origin.into(), Weight::MAX).unwrap()
@@ -294,7 +294,7 @@ benchmarks! {
 	on_runtime_upgrade_noop {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}:  {
-		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_none());
 	}
@@ -306,7 +306,7 @@ benchmarks! {
 		let v = vec![42u8].try_into().ok();
 		MigrationInProgress::<T>::set(v.clone());
 	}:  {
-		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_some());
 		assert_eq!(MigrationInProgress::<T>::get(), v);
@@ -317,7 +317,7 @@ benchmarks! {
 	on_runtime_upgrade {
 		StorageVersion::new(0).put::<Pallet<T>>();
 	}:  {
-		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_some());
 	}
diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 779b713795b64..fa0a95d2ffebb 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -87,12 +87,12 @@ mod address;
 mod benchmarking;
 mod exec;
 mod gas;
-mod migration;
 mod schedule;
 mod storage;
 mod wasm;
 
 pub mod chain_extension;
+pub mod migration;
 pub mod weights;
 
 #[cfg(test)]
@@ -319,6 +319,9 @@ pub mod pallet {
 		/// The maximum length of the debug buffer in bytes.
 		#[pallet::constant]
 		type MaxDebugBufferLen: Get<u32>;
+
+		/// The sequence of migrations applied.
+		type Migrations: MigrateSequence;
 	}
 
 	#[pallet::hooks]
@@ -326,7 +329,7 @@ pub mod pallet {
 		fn on_idle(_block: T::BlockNumber, remaining_weight: Weight) -> Weight {
 			use migration::MigrateResult::*;
 
-			let (result, weight) = Migration::<T>::migrate(remaining_weight);
+			let (result, weight) = Migration::<T, T::Migrations>::migrate(remaining_weight);
 			let remaining_weight = remaining_weight.saturating_sub(weight);
 
 			if !matches!(result, Completed | NoMigrationInProgress) {
@@ -338,7 +341,7 @@ pub mod pallet {
 		}
 
 		fn integrity_test() {
-			Migration::<T>::integrity_test();
+			Migration::<T, T::Migrations>::integrity_test();
 
 			// Total runtime memory limit
 			let max_runtime_mem: u32 = T::Schedule::get().limits.runtime_memory;
@@ -518,7 +521,7 @@ pub mod pallet {
 			storage_deposit_limit: Option<<BalanceOf<T> as codec::HasCompact>::Type>,
 			determinism: Determinism,
 		) -> DispatchResult {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			let origin = ensure_signed(origin)?;
 			Self::bare_upload_code(origin, code, storage_deposit_limit.map(Into::into), determinism)
 				.map(|_| ())
@@ -534,7 +537,7 @@ pub mod pallet {
 			origin: OriginFor<T>,
 			code_hash: CodeHash<T>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			let origin = ensure_signed(origin)?;
 			<PrefabWasmModule<T>>::remove(&origin, code_hash)?;
 			// we waive the fee because removing unused code is beneficial
@@ -558,7 +561,7 @@ pub mod pallet {
 			dest: AccountIdLookupOf<T>,
 			code_hash: CodeHash<T>,
 		) -> DispatchResult {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			ensure_root(origin)?;
 			let dest = T::Lookup::lookup(dest)?;
 			<ContractInfoOf<T>>::try_mutate(&dest, |contract| {
@@ -608,7 +611,7 @@ pub mod pallet {
 			storage_deposit_limit: Option<<BalanceOf<T> as codec::HasCompact>::Type>,
 			data: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			let common = CommonInput {
 				origin: Origin::from_runtime_origin(origin)?,
 				value,
@@ -668,7 +671,7 @@ pub mod pallet {
 			data: Vec<u8>,
 			salt: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			let code_len = code.len() as u32;
 			let data_len = data.len() as u32;
 			let salt_len = salt.len() as u32;
@@ -711,7 +714,7 @@ pub mod pallet {
 			data: Vec<u8>,
 			salt: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T>::ensure_migrated()?;
+			Migration::<T, T::Migrations>::ensure_migrated()?;
 			let data_len = data.len() as u32;
 			let salt_len = salt.len() as u32;
 			let common = CommonInput {
@@ -746,7 +749,7 @@ pub mod pallet {
 			ensure_signed(origin)?;
 
 			let weight_limit = weight_limit.saturating_add(T::WeightInfo::migrate());
-			let (result, weight) = Migration::<T>::migrate(weight_limit);
+			let (result, weight) = Migration::<T, T::Migrations>::migrate(weight_limit);
 
 			match result {
 				Completed =>
@@ -1272,7 +1275,7 @@ impl<T: Config> Invokable<T> for InstantiateInput<T> {
 
 macro_rules! ensure_no_migration_in_progress {
 	() => {
-		if Migration::<T>::in_progress() {
+		if Migration::<T, T::Migrations>::in_progress() {
 			return ContractResult {
 				gas_consumed: Zero::zero(),
 				gas_required: Zero::zero(),
@@ -1412,7 +1415,7 @@ impl<T: Config> Pallet<T> {
 		storage_deposit_limit: Option<BalanceOf<T>>,
 		determinism: Determinism,
 	) -> CodeUploadResult<CodeHash<T>, BalanceOf<T>> {
-		Migration::<T>::ensure_migrated()?;
+		Migration::<T, T::Migrations>::ensure_migrated()?;
 		let schedule = T::Schedule::get();
 		let module = PrefabWasmModule::from_code(
 			code,
@@ -1433,7 +1436,7 @@ impl<T: Config> Pallet<T> {
 
 	/// Query storage of a specified contract under a specified key.
 	pub fn get_storage(address: T::AccountId, key: Vec<u8>) -> GetStorageResult {
-		if Migration::<T>::in_progress() {
+		if Migration::<T, T::Migrations>::in_progress() {
 			return Err(ContractAccessError::MigrationInProgress)
 		}
 		let contract_info =
diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index a75d5cc1a1f4d..c13c5f4681f50 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -18,15 +18,10 @@
 //! Migration framework for pallets.
 
 /// Macro to include all migration modules.
-/// We only want to make these modules public when `runtime-benchmarks` is
-/// enabled, so we can access migration code in benchmarks.
 macro_rules! use_modules {
     ($($module:ident),*) => {
         $(
-            #[cfg(feature = "runtime-benchmarks")]
             pub mod $module;
-            #[cfg(not(feature = "runtime-benchmarks"))]
-            mod $module;
         )*
     };
 }
@@ -58,10 +53,6 @@ fn invalid_version(version: StorageVersion) -> ! {
 /// The cursor used to store the state of the current migration step.
 pub type Cursor = BoundedVec<u8, ConstU32<1024>>;
 
-// In benchmark and tests we use noop migrations, to test and bench the migration framework itself.
-#[cfg(not(any(feature = "runtime-benchmarks", test)))]
-type Migrations<T> = (v9::Migration<T>, v10::Migration<T>, v11::Migration<T>);
-
 /// IsFinished describes whether a migration is finished or not.
 pub enum IsFinished {
 	Yes,
@@ -206,14 +197,14 @@ pub trait MigrateSequence: private::Sealed {
 }
 
 /// Performs all necessary migrations based on `StorageVersion`.
-#[cfg(not(any(feature = "runtime-benchmarks", test)))]
-pub struct Migration<T: Config, M: MigrateSequence = Migrations<T>>(PhantomData<(T, M)>);
-
-/// Custom migration for running runtime-benchmarks and tests.
-#[cfg(any(feature = "runtime-benchmarks", test))]
-pub struct Migration<T: Config, M: MigrateSequence = (NoopMigration<1>, NoopMigration<2>)>(
-	PhantomData<(T, M)>,
-);
+// #[cfg(not(any(feature = "runtime-benchmarks", test)))]
+pub struct Migration<T: Config, M: MigrateSequence>(PhantomData<(T, M)>);
+
+// /// Custom migration for running runtime-benchmarks and tests.
+// #[cfg(any(feature = "runtime-benchmarks", test))]
+// pub struct Migration<T: Config, M: MigrateSequence = (NoopMigration<1>, NoopMigration<2>)>(
+// 	PhantomData<(T, M)>,
+// );
 
 #[cfg(feature = "try-runtime")]
 impl<T: Config, M: MigrateSequence> Migration<T, M> {
diff --git a/frame/contracts/src/tests.rs b/frame/contracts/src/tests.rs
index d23a238dcd158..9425f25adf4b8 100644
--- a/frame/contracts/src/tests.rs
+++ b/frame/contracts/src/tests.rs
@@ -28,8 +28,8 @@ use crate::{
 	wasm::{Determinism, PrefabWasmModule, ReturnCode as RuntimeReturnCode},
 	weights::WeightInfo,
 	BalanceOf, Code, CodeStorage, CollectEvents, Config, ContractInfo, ContractInfoOf, DebugInfo,
-	DefaultAddressGenerator, DeletionQueueCounter, Error, MigrationInProgress, Origin, Pallet,
-	Schedule,
+	DefaultAddressGenerator, DeletionQueueCounter, Error, MigrationInProgress, NoopMigration,
+	Origin, Pallet, Schedule,
 };
 use assert_matches::assert_matches;
 use codec::Encode;
@@ -428,6 +428,7 @@ impl Config for Test {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = UnstableInterface;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 
 pub const ALICE: AccountId32 = AccountId32::new([1u8; 32]);

From e8c493cecdef218476a5a6ce78ce678140996132 Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 13:19:31 +0200
Subject: [PATCH 02/42] remove commented out code

---
 frame/contracts/src/migration.rs | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index c13c5f4681f50..ec8a67c755c48 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -197,15 +197,8 @@ pub trait MigrateSequence: private::Sealed {
 }
 
 /// Performs all necessary migrations based on `StorageVersion`.
-// #[cfg(not(any(feature = "runtime-benchmarks", test)))]
 pub struct Migration<T: Config, M: MigrateSequence>(PhantomData<(T, M)>);
 
-// /// Custom migration for running runtime-benchmarks and tests.
-// #[cfg(any(feature = "runtime-benchmarks", test))]
-// pub struct Migration<T: Config, M: MigrateSequence = (NoopMigration<1>, NoopMigration<2>)>(
-// 	PhantomData<(T, M)>,
-// );
-
 #[cfg(feature = "try-runtime")]
 impl<T: Config, M: MigrateSequence> Migration<T, M> {
 	fn run_all_steps() -> Result<(), TryRuntimeError> {

From 0e629301500114775c71e7e01cf039ed0c5ebb2e Mon Sep 17 00:00:00 2001
From: Juan <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 13:41:50 +0200
Subject: [PATCH 03/42] Update frame/contracts/src/lib.rs

Co-authored-by: PG Herveou <pgherveou@gmail.com>
---
 frame/contracts/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index fa0a95d2ffebb..118ccca94206c 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -320,7 +320,7 @@ pub mod pallet {
 		#[pallet::constant]
 		type MaxDebugBufferLen: Get<u32>;
 
-		/// The sequence of migrations applied.
+		/// The sequence of migration steps that will be applied during a migration.
 		type Migrations: MigrateSequence;
 	}
 

From 14a71755cfb5546c4e78f5fdd6cf54ac1134d9b7 Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 14:01:59 +0200
Subject: [PATCH 04/42] remove Migrations generic

---
 bin/node/runtime/src/lib.rs             |   2 +-
 frame/contracts/src/benchmarking/mod.rs |  10 +-
 frame/contracts/src/lib.rs              |  24 ++---
 frame/contracts/src/migration.rs        | 118 ++++++++++++------------
 4 files changed, 79 insertions(+), 75 deletions(-)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index 33ffe6d4f32cc..dd2accb086a43 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -1983,7 +1983,7 @@ pub type Executive = frame_executive::Executive<
 type Migrations = (
 	pallet_nomination_pools::migration::v2::MigrateToV2<Runtime>,
 	pallet_alliance::migration::Migration<Runtime>,
-	pallet_contracts::Migration<Runtime, <Runtime as pallet_contracts::Config>::Migrations>,
+	pallet_contracts::Migration<Runtime>,
 );
 
 type EventRecord = frame_system::EventRecord<
diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index 27b9aadeed675..b98c05f2503c2 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -272,7 +272,7 @@ benchmarks! {
 	migration_noop {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}:  {
-		Migration::<T, T::Migrations>::migrate(Weight::MAX)
+		Migration::<T>::migrate(Weight::MAX)
 	} verify {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
@@ -281,7 +281,7 @@ benchmarks! {
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();
-		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade();
+		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade();
 		let origin: RawOrigin<<T as frame_system::Config>::AccountId> = RawOrigin::Signed(whitelisted_caller());
 	}: {
 		<Contracts<T>>::migrate(origin.into(), Weight::MAX).unwrap()
@@ -294,7 +294,7 @@ benchmarks! {
 	on_runtime_upgrade_noop {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}:  {
-		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_none());
 	}
@@ -306,7 +306,7 @@ benchmarks! {
 		let v = vec![42u8].try_into().ok();
 		MigrationInProgress::<T>::set(v.clone());
 	}:  {
-		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_some());
 		assert_eq!(MigrationInProgress::<T>::get(), v);
@@ -317,7 +317,7 @@ benchmarks! {
 	on_runtime_upgrade {
 		StorageVersion::new(0).put::<Pallet<T>>();
 	}:  {
-		<Migration::<T, T::Migrations> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
+		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade()
 	} verify {
 		assert!(MigrationInProgress::<T>::get().is_some());
 	}
diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 118ccca94206c..59c9ea23ed38b 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -329,7 +329,7 @@ pub mod pallet {
 		fn on_idle(_block: T::BlockNumber, remaining_weight: Weight) -> Weight {
 			use migration::MigrateResult::*;
 
-			let (result, weight) = Migration::<T, T::Migrations>::migrate(remaining_weight);
+			let (result, weight) = Migration::<T>::migrate(remaining_weight);
 			let remaining_weight = remaining_weight.saturating_sub(weight);
 
 			if !matches!(result, Completed | NoMigrationInProgress) {
@@ -341,7 +341,7 @@ pub mod pallet {
 		}
 
 		fn integrity_test() {
-			Migration::<T, T::Migrations>::integrity_test();
+			Migration::<T>::integrity_test();
 
 			// Total runtime memory limit
 			let max_runtime_mem: u32 = T::Schedule::get().limits.runtime_memory;
@@ -521,7 +521,7 @@ pub mod pallet {
 			storage_deposit_limit: Option<<BalanceOf<T> as codec::HasCompact>::Type>,
 			determinism: Determinism,
 		) -> DispatchResult {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			let origin = ensure_signed(origin)?;
 			Self::bare_upload_code(origin, code, storage_deposit_limit.map(Into::into), determinism)
 				.map(|_| ())
@@ -537,7 +537,7 @@ pub mod pallet {
 			origin: OriginFor<T>,
 			code_hash: CodeHash<T>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			let origin = ensure_signed(origin)?;
 			<PrefabWasmModule<T>>::remove(&origin, code_hash)?;
 			// we waive the fee because removing unused code is beneficial
@@ -561,7 +561,7 @@ pub mod pallet {
 			dest: AccountIdLookupOf<T>,
 			code_hash: CodeHash<T>,
 		) -> DispatchResult {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			ensure_root(origin)?;
 			let dest = T::Lookup::lookup(dest)?;
 			<ContractInfoOf<T>>::try_mutate(&dest, |contract| {
@@ -611,7 +611,7 @@ pub mod pallet {
 			storage_deposit_limit: Option<<BalanceOf<T> as codec::HasCompact>::Type>,
 			data: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			let common = CommonInput {
 				origin: Origin::from_runtime_origin(origin)?,
 				value,
@@ -671,7 +671,7 @@ pub mod pallet {
 			data: Vec<u8>,
 			salt: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			let code_len = code.len() as u32;
 			let data_len = data.len() as u32;
 			let salt_len = salt.len() as u32;
@@ -714,7 +714,7 @@ pub mod pallet {
 			data: Vec<u8>,
 			salt: Vec<u8>,
 		) -> DispatchResultWithPostInfo {
-			Migration::<T, T::Migrations>::ensure_migrated()?;
+			Migration::<T>::ensure_migrated()?;
 			let data_len = data.len() as u32;
 			let salt_len = salt.len() as u32;
 			let common = CommonInput {
@@ -749,7 +749,7 @@ pub mod pallet {
 			ensure_signed(origin)?;
 
 			let weight_limit = weight_limit.saturating_add(T::WeightInfo::migrate());
-			let (result, weight) = Migration::<T, T::Migrations>::migrate(weight_limit);
+			let (result, weight) = Migration::<T>::migrate(weight_limit);
 
 			match result {
 				Completed =>
@@ -1275,7 +1275,7 @@ impl<T: Config> Invokable<T> for InstantiateInput<T> {
 
 macro_rules! ensure_no_migration_in_progress {
 	() => {
-		if Migration::<T, T::Migrations>::in_progress() {
+		if Migration::<T>::in_progress() {
 			return ContractResult {
 				gas_consumed: Zero::zero(),
 				gas_required: Zero::zero(),
@@ -1415,7 +1415,7 @@ impl<T: Config> Pallet<T> {
 		storage_deposit_limit: Option<BalanceOf<T>>,
 		determinism: Determinism,
 	) -> CodeUploadResult<CodeHash<T>, BalanceOf<T>> {
-		Migration::<T, T::Migrations>::ensure_migrated()?;
+		Migration::<T>::ensure_migrated()?;
 		let schedule = T::Schedule::get();
 		let module = PrefabWasmModule::from_code(
 			code,
@@ -1436,7 +1436,7 @@ impl<T: Config> Pallet<T> {
 
 	/// Query storage of a specified contract under a specified key.
 	pub fn get_storage(address: T::AccountId, key: Vec<u8>) -> GetStorageResult {
-		if Migration::<T, T::Migrations>::in_progress() {
+		if Migration::<T>::in_progress() {
 			return Err(ContractAccessError::MigrationInProgress)
 		}
 		let contract_info =
diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index ec8a67c755c48..ad85da0477148 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -17,16 +17,10 @@
 
 //! Migration framework for pallets.
 
-/// Macro to include all migration modules.
-macro_rules! use_modules {
-    ($($module:ident),*) => {
-        $(
-            pub mod $module;
-        )*
-    };
-}
+pub mod v10;
+pub mod v11;
+pub mod v9;
 
-use_modules!(v9, v10, v11);
 use crate::{weights::WeightInfo, Config, Error, MigrationInProgress, Pallet, Weight, LOG_TARGET};
 use codec::{Codec, Decode};
 use frame_support::{
@@ -197,16 +191,16 @@ pub trait MigrateSequence: private::Sealed {
 }
 
 /// Performs all necessary migrations based on `StorageVersion`.
-pub struct Migration<T: Config, M: MigrateSequence>(PhantomData<(T, M)>);
+pub struct Migration<T: Config>(PhantomData<T>);
 
 #[cfg(feature = "try-runtime")]
-impl<T: Config, M: MigrateSequence> Migration<T, M> {
+impl<T: Config> Migration<T> {
 	fn run_all_steps() -> Result<(), TryRuntimeError> {
 		let mut weight = Weight::zero();
 		let name = <Pallet<T>>::name();
 		loop {
 			let in_progress_version = <Pallet<T>>::on_chain_storage_version() + 1;
-			let state = M::pre_upgrade_step(in_progress_version)?;
+			let state = T::Migrations::pre_upgrade_step(in_progress_version)?;
 			let (status, w) = Self::migrate(Weight::MAX);
 			weight.saturating_accrue(w);
 			log::info!(
@@ -215,7 +209,7 @@ impl<T: Config, M: MigrateSequence> Migration<T, M> {
 				in_progress_version,
 				weight
 			);
-			M::post_upgrade_step(in_progress_version, state)?;
+			T::Migrations::post_upgrade_step(in_progress_version, state)?;
 			if matches!(status, MigrateResult::Completed) {
 				break
 			}
@@ -227,7 +221,7 @@ impl<T: Config, M: MigrateSequence> Migration<T, M> {
 	}
 }
 
-impl<T: Config, M: MigrateSequence> OnRuntimeUpgrade for Migration<T, M> {
+impl<T: Config> OnRuntimeUpgrade for Migration<T> {
 	fn on_runtime_upgrade() -> Weight {
 		let name = <Pallet<T>>::name();
 		let latest_version = <Pallet<T>>::current_storage_version();
@@ -258,7 +252,7 @@ impl<T: Config, M: MigrateSequence> OnRuntimeUpgrade for Migration<T, M> {
 			"{name}: Upgrading storage from {storage_version:?} to {latest_version:?}.",
 		);
 
-		let cursor = M::new(storage_version + 1);
+		let cursor = T::Migrations::new(storage_version + 1);
 		MigrationInProgress::<T>::set(Some(cursor));
 
 		#[cfg(feature = "try-runtime")]
@@ -279,11 +273,14 @@ impl<T: Config, M: MigrateSequence> OnRuntimeUpgrade for Migration<T, M> {
 			target: LOG_TARGET,
 			"{}: Range supported {:?}, range requested {:?}",
 			<Pallet<T>>::name(),
-			M::VERSION_RANGE,
+			T::Migrations::VERSION_RANGE,
 			(storage_version, target_version)
 		);
 
-		ensure!(M::is_upgrade_supported(storage_version, target_version), "Unsupported upgrade");
+		ensure!(
+			T::Migrations::is_upgrade_supported(storage_version, target_version),
+			"Unsupported upgrade"
+		);
 		Ok(Default::default())
 	}
 }
@@ -308,11 +305,11 @@ pub enum StepResult {
 	Completed { steps_done: u32 },
 }
 
-impl<T: Config, M: MigrateSequence> Migration<T, M> {
-	/// Verify that each migration's step of the MigrateSequence fits into `Cursor`.
+impl<T: Config> Migration<T> {
+	/// Verify that each migration's step of the [`T::Migrations`] sequence fits into `Cursor`.
 	pub(crate) fn integrity_test() {
 		let max_weight = <T as frame_system::Config>::BlockWeights::get().max_block;
-		M::integrity_test(max_weight)
+		T::Migrations::integrity_test(max_weight)
 	}
 
 	/// Migrate
@@ -341,33 +338,36 @@ impl<T: Config, M: MigrateSequence> Migration<T, M> {
 				in_progress_version,
 			);
 
-			let result =
-				match M::steps(in_progress_version, cursor_before.as_ref(), &mut weight_left) {
-					StepResult::InProgress { cursor, steps_done } => {
-						*progress = Some(cursor);
+			let result = match T::Migrations::steps(
+				in_progress_version,
+				cursor_before.as_ref(),
+				&mut weight_left,
+			) {
+				StepResult::InProgress { cursor, steps_done } => {
+					*progress = Some(cursor);
+					MigrateResult::InProgress { steps_done }
+				},
+				StepResult::Completed { steps_done } => {
+					in_progress_version.put::<Pallet<T>>();
+					if <Pallet<T>>::current_storage_version() != in_progress_version {
+						log::info!(
+							target: LOG_TARGET,
+							"{name}: Next migration is {:?},",
+							in_progress_version + 1
+						);
+						*progress = Some(T::Migrations::new(in_progress_version + 1));
 						MigrateResult::InProgress { steps_done }
-					},
-					StepResult::Completed { steps_done } => {
-						in_progress_version.put::<Pallet<T>>();
-						if <Pallet<T>>::current_storage_version() != in_progress_version {
-							log::info!(
-								target: LOG_TARGET,
-								"{name}: Next migration is {:?},",
-								in_progress_version + 1
-							);
-							*progress = Some(M::new(in_progress_version + 1));
-							MigrateResult::InProgress { steps_done }
-						} else {
-							log::info!(
-								target: LOG_TARGET,
-								"{name}: All migrations done. At version {:?},",
-								in_progress_version
-							);
-							*progress = None;
-							MigrateResult::Completed
-						}
-					},
-				};
+					} else {
+						log::info!(
+							target: LOG_TARGET,
+							"{name}: All migrations done. At version {:?},",
+							in_progress_version
+						);
+						*progress = None;
+						MigrateResult::Completed
+					}
+				},
+			};
 
 			(result, weight_limit.saturating_sub(weight_left))
 		})
@@ -511,11 +511,14 @@ mod test {
 
 	#[test]
 	fn is_upgrade_supported_works() {
-		type M = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
+		type Migrations = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
 
 		[(1, 1), (8, 11), (9, 11)].into_iter().for_each(|(from, to)| {
 			assert!(
-				M::is_upgrade_supported(StorageVersion::new(from), StorageVersion::new(to)),
+				Migrations::is_upgrade_supported(
+					StorageVersion::new(from),
+					StorageVersion::new(to)
+				),
 				"{} -> {} is supported",
 				from,
 				to
@@ -524,7 +527,10 @@ mod test {
 
 		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
 			assert!(
-				!M::is_upgrade_supported(StorageVersion::new(from), StorageVersion::new(to)),
+				!Migrations::is_upgrade_supported(
+					StorageVersion::new(from),
+					StorageVersion::new(to)
+				),
 				"{} -> {} is not supported",
 				from,
 				to
@@ -534,27 +540,26 @@ mod test {
 
 	#[test]
 	fn steps_works() {
-		type M = (MockMigration<2>, MockMigration<3>);
+		type Migrations = (MockMigration<2>, MockMigration<3>);
 		let version = StorageVersion::new(2);
-		let mut cursor = M::new(version);
+		let mut cursor = Migrations::new(version);
 
 		let mut weight = Weight::from_all(2);
-		let result = M::steps(version, &cursor, &mut weight);
+		let result = Migrations::steps(version, &cursor, &mut weight);
 		cursor = vec![1u8, 0].try_into().unwrap();
 		assert_eq!(result, StepResult::InProgress { cursor: cursor.clone(), steps_done: 1 });
 		assert_eq!(weight, Weight::from_all(1));
 
 		let mut weight = Weight::from_all(2);
 		assert_eq!(
-			M::steps(version, &cursor, &mut weight),
+			Migrations::steps(version, &cursor, &mut weight),
 			StepResult::Completed { steps_done: 1 }
 		);
 	}
 
 	#[test]
 	fn no_migration_in_progress_works() {
-		type M = (MockMigration<1>, MockMigration<2>);
-		type TestMigration = Migration<Test, M>;
+		type TestMigration = Migration<Test>;
 
 		ExtBuilder::default().build().execute_with(|| {
 			assert_eq!(StorageVersion::get::<Pallet<Test>>(), 2);
@@ -564,8 +569,7 @@ mod test {
 
 	#[test]
 	fn migration_works() {
-		type M = (MockMigration<1>, MockMigration<2>);
-		type TestMigration = Migration<Test, M>;
+		type TestMigration = Migration<Test>;
 
 		ExtBuilder::default().set_storage_version(0).build().execute_with(|| {
 			assert_eq!(StorageVersion::get::<Pallet<Test>>(), 0);

From 2601d79a37c70fde3d81e891957d9b5d0f946a1c Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 17:11:59 +0200
Subject: [PATCH 05/42] make runtime use noop migrations

---
 bin/node/runtime/src/lib.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index dd2accb086a43..dd4b14b1889b5 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -55,7 +55,7 @@ use frame_system::{
 pub use node_primitives::{AccountId, Signature};
 use node_primitives::{AccountIndex, Balance, BlockNumber, Hash, Index, Moment};
 use pallet_asset_conversion::{NativeOrAssetId, NativeOrAssetIdConverter};
-use pallet_contracts::migration::{v10, v11, v9};
+use pallet_contracts::NoopMigration;
 use pallet_election_provider_multi_phase::SolutionAccuracyOf;
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
 use pallet_nfts::PalletFeatures;
@@ -1241,7 +1241,7 @@ impl pallet_contracts::Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<false>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
-	type Migrations = (v9::Migration<Runtime>, v10::Migration<Runtime>, v11::Migration<Runtime>);
+	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 
 impl pallet_sudo::Config for Runtime {

From e88854a39dbbd133b647b0b5ca9ede0a525b0bbe Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Tue, 6 Jun 2023 17:30:01 +0200
Subject: [PATCH 06/42] restrict is_upgrade_supported

---
 frame/contracts/src/migration.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index ad85da0477148..ce0e018f0ac3d 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -186,7 +186,7 @@ pub trait MigrateSequence: private::Sealed {
 			return false
 		};
 
-		in_storage >= first_supported && target == high
+		in_storage == first_supported && target == high
 	}
 }
 
@@ -513,7 +513,7 @@ mod test {
 	fn is_upgrade_supported_works() {
 		type Migrations = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
 
-		[(1, 1), (8, 11), (9, 11)].into_iter().for_each(|(from, to)| {
+		[(1, 1), (8, 11)].into_iter().for_each(|(from, to)| {
 			assert!(
 				Migrations::is_upgrade_supported(
 					StorageVersion::new(from),
@@ -525,7 +525,7 @@ mod test {
 			)
 		});
 
-		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
+		[(1, 0), (0, 3), (7, 11), (8, 10), (9, 11)].into_iter().for_each(|(from, to)| {
 			assert!(
 				!Migrations::is_upgrade_supported(
 					StorageVersion::new(from),

From a8caaf2f492bb46db9de8c11a0df70d91692a898 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Tue, 6 Jun 2023 23:53:59 +0200
Subject: [PATCH 07/42] Update contract multi-block migration

Ensure that we do as many steps as possible given the weight limit passed to on_idle
---
 frame/contracts/src/lib.rs   | 22 ++++++++++++++++------
 frame/contracts/src/tests.rs | 18 ++++++++++++++++++
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 59c9ea23ed38b..79de7fbf6ab75 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -328,12 +328,22 @@ pub mod pallet {
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
 		fn on_idle(_block: T::BlockNumber, remaining_weight: Weight) -> Weight {
 			use migration::MigrateResult::*;
-
-			let (result, weight) = Migration::<T>::migrate(remaining_weight);
-			let remaining_weight = remaining_weight.saturating_sub(weight);
-
-			if !matches!(result, Completed | NoMigrationInProgress) {
-				return weight
+			let mut remaining_weight = remaining_weight;
+
+			loop {
+				let (result, weight) = Migration::<T>::migrate(remaining_weight);
+				remaining_weight.saturating_reduce(weight);
+
+				match result {
+					// There is not enough weight to perform a migration, or make any progress, we
+					// just return the remaining weight.
+					NoMigrationPerformed | InProgress { steps_done: 0 } => return remaining_weight,
+					// Migration is still in progress, we can start the next step.
+					InProgress { .. } => {},
+					// There are no migration in progress, or we are done with all migrations, we
+					// can do some more work with the remaining weight.
+					Completed | NoMigrationInProgress => break,
+				}
 			}
 
 			ContractInfo::<T>::process_deletion_queue_batch(remaining_weight)
diff --git a/frame/contracts/src/tests.rs b/frame/contracts/src/tests.rs
index 9425f25adf4b8..48b56128d5298 100644
--- a/frame/contracts/src/tests.rs
+++ b/frame/contracts/src/tests.rs
@@ -559,6 +559,24 @@ fn calling_plain_account_fails() {
 	});
 }
 
+#[test]
+fn migration_on_idle_hooks_works() {
+	// Defines expectations of how many migration steps can be done given the weight limit.
+	let tests = [
+		(Weight::zero(), 0),
+		(<Test as Config>::WeightInfo::migrate() + 1.into(), 1),
+		(Weight::MAX, 2),
+	];
+
+	for (weight, expected_version) in tests {
+		ExtBuilder::default().set_storage_version(0).build().execute_with(|| {
+			MigrationInProgress::<Test>::set(Some(Default::default()));
+			Contracts::on_idle(System::block_number(), weight);
+			assert_eq!(StorageVersion::get::<Pallet<Test>>(), expected_version);
+		});
+	}
+}
+
 #[test]
 fn migration_in_progress_works() {
 	let (wasm, code_hash) = compile_module::<Test>("dummy").unwrap();

From 1400ab05eb3452b534d5999e82dd8f4fc528913b Mon Sep 17 00:00:00 2001
From: Juan Girini <juangirini@gmail.com>
Date: Wed, 7 Jun 2023 11:51:57 +0200
Subject: [PATCH 08/42] undo is_upgrade_supported change

---
 frame/contracts/src/migration.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index ce0e018f0ac3d..ad85da0477148 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -186,7 +186,7 @@ pub trait MigrateSequence: private::Sealed {
 			return false
 		};
 
-		in_storage == first_supported && target == high
+		in_storage >= first_supported && target == high
 	}
 }
 
@@ -513,7 +513,7 @@ mod test {
 	fn is_upgrade_supported_works() {
 		type Migrations = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
 
-		[(1, 1), (8, 11)].into_iter().for_each(|(from, to)| {
+		[(1, 1), (8, 11), (9, 11)].into_iter().for_each(|(from, to)| {
 			assert!(
 				Migrations::is_upgrade_supported(
 					StorageVersion::new(from),
@@ -525,7 +525,7 @@ mod test {
 			)
 		});
 
-		[(1, 0), (0, 3), (7, 11), (8, 10), (9, 11)].into_iter().for_each(|(from, to)| {
+		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
 			assert!(
 				!Migrations::is_upgrade_supported(
 					StorageVersion::new(from),

From cc7609c9275d1fa03fde4d5b139100777bc4b96b Mon Sep 17 00:00:00 2001
From: Juan <juangirini@gmail.com>
Date: Wed, 7 Jun 2023 14:14:43 +0200
Subject: [PATCH 09/42] Update bin/node/runtime/src/lib.rs

Co-authored-by: PG Herveou <pgherveou@gmail.com>
---
 bin/node/runtime/src/lib.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index dd4b14b1889b5..a5fe7465a3818 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -1241,6 +1241,9 @@ impl pallet_contracts::Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<false>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+    #[cfg(not(feature = "runtime-benchmarks"))]
+	type Migrations = ();
+    #[cfg(feature = "runtime-benchmarks")]
 	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 

From 92360cde3f35a794f038410f7b8043a9e4d58f26 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 15:17:05 +0200
Subject: [PATCH 10/42] wip

---
 frame/contracts/src/migration.rs     | 84 +++++++++++++++++-----------
 frame/contracts/src/migration/v10.rs |  4 +-
 frame/contracts/src/migration/v11.rs |  4 +-
 frame/contracts/src/migration/v9.rs  |  4 +-
 4 files changed, 57 insertions(+), 39 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index ce0e018f0ac3d..f2122d1baf5c5 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -15,7 +15,45 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//! Migration framework for pallets.
+//! Multi-block Migration framework for pallet-contracts.
+//!
+//! This module allows us to define a migration as a sequence of [`MigrationStep`]s that can be
+//! executed across multiple blocks.
+//!
+//! # Usage
+//!
+//! A migration step is defined under `src/migration/vX.rs`, where `X` is the version number.
+//! For example, `vX.rs` defines a migration from version X to version X + 1.
+//!
+//! ## Example:
+//!
+//! To configure a migration to v12 for a runtime using v9 of `pallet-contracts` on the chain, you
+//! would set the `Migrations` trait as follows:
+//!
+//! ```rust
+//! use pallet_contracts::migration::{v10, v11, v12};
+//! type Migrations = (v10, v11, v12);
+//! ```
+//!
+//! ## Notes:
+//!
+//! - Migrations should always be tested with `try-runtime` before being deployed.
+//! - By testing with `try-runtime` against a live network, you ensure that all migration steps work
+//!   and that you have included the required steps.
+//!
+//! ## Low Level / Implementation Details
+//!
+//! When a migration starts and [`OnRuntimeUpgrade::on_runtime_upgrade`] is called, instead of
+//! performing the actual migration, we set a custom storage item, `MigrationInProgress`. This
+//! storage item defines a [`Cursor`] for the current migration step.
+//!
+//! If the `MigrationInProgress` storage item exists, it means a migration is in progress, and its
+//! value holds a cursor for the current migration step. These migration steps are executed during
+//! [`Hooks<BlockNumber>::on_idle`] or when the [`Pallet::migrate`] dispatchable is
+//! called.
+//!
+//! While the migration is in progress, all dispatchables except `migrate`, are blocked, and returns
+//! a `MigrationInProgress` error.
 
 pub mod v10;
 pub mod v11;
@@ -57,7 +95,7 @@ pub enum IsFinished {
 ///
 /// The migration is done in steps. The migration is finished when
 /// `step()` returns `IsFinished::Yes`.
-pub trait Migrate: Codec + MaxEncodedLen + Default {
+pub trait MigrationStep: Codec + MaxEncodedLen + Default {
 	/// Returns the version of the migration.
 	const VERSION: u16;
 
@@ -110,7 +148,7 @@ pub trait Migrate: Codec + MaxEncodedLen + Default {
 #[derive(frame_support::DefaultNoBound, Encode, Decode, MaxEncodedLen)]
 pub struct NoopMigration<const N: u16>;
 
-impl<const N: u16> Migrate for NoopMigration<N> {
+impl<const N: u16> MigrationStep for NoopMigration<N> {
 	const VERSION: u16 = N;
 	fn max_step_weight() -> Weight {
 		Weight::zero()
@@ -122,10 +160,10 @@ impl<const N: u16> Migrate for NoopMigration<N> {
 }
 
 mod private {
-	use crate::migration::Migrate;
+	use crate::migration::MigrationStep;
 	pub trait Sealed {}
 	#[impl_trait_for_tuples::impl_for_tuples(10)]
-	#[tuple_types_custom_trait_bound(Migrate)]
+	#[tuple_types_custom_trait_bound(MigrationStep)]
 	impl Sealed for Tuple {}
 }
 
@@ -172,21 +210,10 @@ pub trait MigrateSequence: private::Sealed {
 
 	/// Returns whether migrating from `in_storage` to `target` is supported.
 	///
-	/// A migration is supported if (in_storage + 1, target) is contained by `VERSION_RANGE`.
+	/// A migration is supported if `VERSION_RANGE` is (in_storage + 1, target).
 	fn is_upgrade_supported(in_storage: StorageVersion, target: StorageVersion) -> bool {
-		if in_storage == target {
-			return true
-		}
-		if in_storage > target {
-			return false
-		}
-
 		let (low, high) = Self::VERSION_RANGE;
-		let Some(first_supported) = low.checked_sub(1) else {
-			return false
-		};
-
-		in_storage == first_supported && target == high
+		target == high && in_storage + 1 == low
 	}
 }
 
@@ -387,7 +414,7 @@ impl<T: Config> Migration<T> {
 }
 
 #[impl_trait_for_tuples::impl_for_tuples(10)]
-#[tuple_types_custom_trait_bound(Migrate)]
+#[tuple_types_custom_trait_bound(MigrationStep)]
 impl MigrateSequence for Tuple {
 	const VERSION_RANGE: (u16, u16) = {
 		let mut versions: (u16, u16) = (0, 0);
@@ -487,7 +514,7 @@ mod test {
 		count: u16,
 	}
 
-	impl<const N: u16> Migrate for MockMigration<N> {
+	impl<const N: u16> MigrationStep for MockMigration<N> {
 		const VERSION: u16 = N;
 		fn max_step_weight() -> Weight {
 			Weight::from_all(1)
@@ -512,20 +539,11 @@ mod test {
 	#[test]
 	fn is_upgrade_supported_works() {
 		type Migrations = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
+		assert!(Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(11)));
+		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(9), StorageVersion::new(11)));
+		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(12)));
 
-		[(1, 1), (8, 11)].into_iter().for_each(|(from, to)| {
-			assert!(
-				Migrations::is_upgrade_supported(
-					StorageVersion::new(from),
-					StorageVersion::new(to)
-				),
-				"{} -> {} is supported",
-				from,
-				to
-			)
-		});
-
-		[(1, 0), (0, 3), (7, 11), (8, 10), (9, 11)].into_iter().for_each(|(from, to)| {
+		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
 			assert!(
 				!Migrations::is_upgrade_supported(
 					StorageVersion::new(from),
diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index cddf67a53c4f8..8d5897d15caee 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -21,7 +21,7 @@
 use crate::{
 	address::AddressGenerator,
 	exec::AccountIdOf,
-	migration::{IsFinished, Migrate},
+	migration::{IsFinished, MigrationStep},
 	weights::WeightInfo,
 	BalanceOf, CodeHash, Config, Pallet, TrieId, Weight, LOG_TARGET,
 };
@@ -117,7 +117,7 @@ pub struct Migration<T: Config> {
 type ContractInfoOf<T: Config> =
 	StorageMap<Pallet<T>, Twox64Concat, <T as frame_system::Config>::AccountId, ContractInfo<T>>;
 
-impl<T: Config> Migrate for Migration<T> {
+impl<T: Config> MigrationStep for Migration<T> {
 	const VERSION: u16 = 10;
 
 	fn max_step_weight() -> Weight {
diff --git a/frame/contracts/src/migration/v11.rs b/frame/contracts/src/migration/v11.rs
index 27a4b96431e06..59e4f5b2862c4 100644
--- a/frame/contracts/src/migration/v11.rs
+++ b/frame/contracts/src/migration/v11.rs
@@ -19,7 +19,7 @@
 //! See <https://github.com/paritytech/substrate/pull/13702>.
 
 use crate::{
-	migration::{IsFinished, Migrate},
+	migration::{IsFinished, MigrationStep},
 	weights::WeightInfo,
 	Config, Pallet, TrieId, Weight, LOG_TARGET,
 };
@@ -69,7 +69,7 @@ pub struct Migration<T: Config> {
 	_phantom: PhantomData<T>,
 }
 
-impl<T: Config> Migrate for Migration<T> {
+impl<T: Config> MigrationStep for Migration<T> {
 	const VERSION: u16 = 11;
 
 	// It would be more correct to make our use the now removed [DeletionQueueDepth](https://github.com/paritytech/substrate/pull/13702/files#diff-70e9723e9db62816e35f6f885b6770a8449c75a6c2733e9fa7a245fe52c4656c)
diff --git a/frame/contracts/src/migration/v9.rs b/frame/contracts/src/migration/v9.rs
index 3dd86a89cf06d..2aed926e632bf 100644
--- a/frame/contracts/src/migration/v9.rs
+++ b/frame/contracts/src/migration/v9.rs
@@ -18,7 +18,7 @@
 //! Update `CodeStorage` with the new `determinism` field.
 
 use crate::{
-	migration::{IsFinished, Migrate},
+	migration::{IsFinished, MigrationStep},
 	weights::WeightInfo,
 	CodeHash, Config, Determinism, Pallet, Weight, LOG_TARGET,
 };
@@ -83,7 +83,7 @@ pub struct Migration<T: Config> {
 	_phantom: PhantomData<T>,
 }
 
-impl<T: Config> Migrate for Migration<T> {
+impl<T: Config> MigrationStep for Migration<T> {
 	const VERSION: u16 = 9;
 
 	fn max_step_weight() -> Weight {

From 137ecc8bd0f1070eaae89896dc26c4fd3ac4a497 Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 15:18:13 +0200
Subject: [PATCH 11/42] fix comment (#14316)

---
 frame/contracts/src/benchmarking/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index b98c05f2503c2..85a5df6eed9ab 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -277,7 +277,7 @@ benchmarks! {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
 
-	// This benchmarks the weight of executing Migration::migrate when there are no migration in progress.
+	// This benchmarks the weight of executing 1 `NoopMigraton`
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();

From 27e5cf85540703660ef8a5a17926a9acd1b23ef3 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 15:22:23 +0200
Subject: [PATCH 12/42] fix test

---
 frame/contracts/src/migration.rs | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index f2122d1baf5c5..9c6d83b8b3435 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -542,18 +542,6 @@ mod test {
 		assert!(Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(11)));
 		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(9), StorageVersion::new(11)));
 		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(12)));
-
-		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
-			assert!(
-				!Migrations::is_upgrade_supported(
-					StorageVersion::new(from),
-					StorageVersion::new(to)
-				),
-				"{} -> {} is not supported",
-				from,
-				to
-			)
-		});
 	}
 
 	#[test]

From 2935e99998e644b4f60c4298b203ed7b30b83ec1 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 15:28:08 +0200
Subject: [PATCH 13/42] fix

---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 9c6d83b8b3435..7a5e79ef09eca 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -44,7 +44,7 @@
 //! ## Low Level / Implementation Details
 //!
 //! When a migration starts and [`OnRuntimeUpgrade::on_runtime_upgrade`] is called, instead of
-//! performing the actual migration, we set a custom storage item, `MigrationInProgress`. This
+//! performing the actual migration, we set a custom storage item `MigrationInProgress`. This
 //! storage item defines a [`Cursor`] for the current migration step.
 //!
 //! If the `MigrationInProgress` storage item exists, it means a migration is in progress, and its

From a4bb30251991840effdae3aade647ecb02fb7fcb Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 15:55:30 +0200
Subject: [PATCH 14/42] Update frame/contracts/src/migration.rs

Co-authored-by: Juan <juangirini@gmail.com>
---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 7a5e79ef09eca..9f17d99c6be2d 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -32,7 +32,7 @@
 //!
 //! ```rust
 //! use pallet_contracts::migration::{v10, v11, v12};
-//! type Migrations = (v10, v11, v12);
+//! type Migrations = (v9::Migration<Runtime>, v10::Migration<Runtime>, v11::Migration<Runtime>);
 //! ```
 //!
 //! ## Notes:

From f3e81ce8c5a673fb98a7ec70ca602d270036f7d1 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Wed, 7 Jun 2023 21:32:35 +0200
Subject: [PATCH 15/42] fix test doc

---
 bin/node/runtime/src/lib.rs      | 4 ++--
 frame/contracts/src/migration.rs | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index a5fe7465a3818..86c2758db3751 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -1241,9 +1241,9 @@ impl pallet_contracts::Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<false>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
-    #[cfg(not(feature = "runtime-benchmarks"))]
+	#[cfg(not(feature = "runtime-benchmarks"))]
 	type Migrations = ();
-    #[cfg(feature = "runtime-benchmarks")]
+	#[cfg(feature = "runtime-benchmarks")]
 	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 
diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 9f17d99c6be2d..81fac2cdb94ad 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -30,8 +30,9 @@
 //! To configure a migration to v12 for a runtime using v9 of `pallet-contracts` on the chain, you
 //! would set the `Migrations` trait as follows:
 //!
-//! ```rust
-//! use pallet_contracts::migration::{v10, v11, v12};
+//! ```
+//! use pallet_contracts::migration::{v9, v10, v11};
+//! # pub enum Runtime {};
 //! type Migrations = (v9::Migration<Runtime>, v10::Migration<Runtime>, v11::Migration<Runtime>);
 //! ```
 //!

From f10f5bd8dc845b539d11e7006bda9ebd7ecc16cf Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Thu, 8 Jun 2023 15:09:14 +0200
Subject: [PATCH 16/42] Apply suggestions from code review

Co-authored-by: Sasha Gryaznov <hi@agryaznov.com>
---
 frame/contracts/src/lib.rs       | 6 +++---
 frame/contracts/src/migration.rs | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 79de7fbf6ab75..5b46dd1df4725 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -339,9 +339,9 @@ pub mod pallet {
 					// just return the remaining weight.
 					NoMigrationPerformed | InProgress { steps_done: 0 } => return remaining_weight,
 					// Migration is still in progress, we can start the next step.
-					InProgress { .. } => {},
-					// There are no migration in progress, or we are done with all migrations, we
-					// can do some more work with the remaining weight.
+					InProgress { .. } => continue,
+					// Either no migration is in progress, or we are done with all migrations, we
+					// can do some more other work with the remaining weight.
 					Completed | NoMigrationInProgress => break,
 				}
 			}
diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 81fac2cdb94ad..e4eff0f263ec0 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -23,12 +23,12 @@
 //! # Usage
 //!
 //! A migration step is defined under `src/migration/vX.rs`, where `X` is the version number.
-//! For example, `vX.rs` defines a migration from version X to version X + 1.
+//! For example, `vX.rs` defines a migration from version `X - 1` to version `X`.
 //!
 //! ## Example:
 //!
-//! To configure a migration to v12 for a runtime using v9 of `pallet-contracts` on the chain, you
-//! would set the `Migrations` trait as follows:
+//! To configure a migration to `v12` for a runtime using `v9` of pallet-contracts on the chain, you
+//! would set the `Migrations` type as follows:
 //!
 //! ```
 //! use pallet_contracts::migration::{v9, v10, v11};

From dc556df320705862cbf01bcdbbe6acb799a0d666 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Thu, 8 Jun 2023 15:15:01 +0200
Subject: [PATCH 17/42] Fix compilation with feature runtime-benchmarks

---
 frame/contracts/src/benchmarking/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index 85a5df6eed9ab..dcfb3f841c02a 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -30,7 +30,7 @@ use self::{
 };
 use crate::{
 	exec::{AccountIdOf, Key},
-	migration::{v10, v11, v9, Migrate},
+	migration::{v10, v11, v9, MigrationStep},
 	wasm::CallFlags,
 	Pallet as Contracts, *,
 };

From a7ef99728e3b79a38eda90831197165495bcc2d7 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Thu, 8 Jun 2023 15:18:46 +0200
Subject: [PATCH 18/42] fix example

---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index e4eff0f263ec0..eb330882aa82d 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -27,7 +27,7 @@
 //!
 //! ## Example:
 //!
-//! To configure a migration to `v12` for a runtime using `v9` of pallet-contracts on the chain, you
+//! To configure a migration to `v11` for a runtime using `v8` of pallet-contracts on the chain, you
 //! would set the `Migrations` type as follows:
 //!
 //! ```

From 6a89133090d77002224d3aa865aa85f57e835acd Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 11:59:12 +0200
Subject: [PATCH 19/42] fix  cargo doc --document-private-items

---
 frame/contracts/src/migration.rs     | 3 ++-
 frame/contracts/src/storage/meter.rs | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index eb330882aa82d..fe63f5ef57347 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -334,7 +334,8 @@ pub enum StepResult {
 }
 
 impl<T: Config> Migration<T> {
-	/// Verify that each migration's step of the [`T::Migrations`] sequence fits into `Cursor`.
+	/// Verify that each migration's step of the [`Config::Migrations`] sequence fits into
+	/// `Cursor`.
 	pub(crate) fn integrity_test() {
 		let max_weight = <T as frame_system::Config>::BlockWeights::get().max_block;
 		T::Migrations::integrity_test(max_weight)
diff --git a/frame/contracts/src/storage/meter.rs b/frame/contracts/src/storage/meter.rs
index 506f4f0d86649..e5caa68a88482 100644
--- a/frame/contracts/src/storage/meter.rs
+++ b/frame/contracts/src/storage/meter.rs
@@ -90,7 +90,7 @@ pub trait Ext<T: Config> {
 
 /// This [`Ext`] is used for actual on-chain execution when balance needs to be charged.
 ///
-/// It uses [`ReservableCurrency`] in order to do accomplish the reserves.
+/// It uses [`frame_support::traits::ReservableCurrency`] in order to do accomplish the reserves.
 pub enum ReservingExt {}
 
 /// Used to implement a type state pattern for the meter.

From 86e66960deffa601e290074ece42a3ebcbc0d662 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 13:46:59 +0200
Subject: [PATCH 20/42] private links

---
 frame/contracts/src/lib.rs       | 1 +
 frame/contracts/src/migration.rs | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 5b46dd1df4725..924ccf5a8633c 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -80,6 +80,7 @@
 //! an [`eDSL`](https://wiki.haskell.org/Embedded_domain_specific_language) that enables writing
 //! WebAssembly based smart contracts in the Rust programming language.
 
+#![allow(rustdoc::private_intra_doc_links)]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(feature = "runtime-benchmarks", recursion_limit = "1024")]
 
diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index fe63f5ef57347..4b5f95df5ec81 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -45,10 +45,10 @@
 //! ## Low Level / Implementation Details
 //!
 //! When a migration starts and [`OnRuntimeUpgrade::on_runtime_upgrade`] is called, instead of
-//! performing the actual migration, we set a custom storage item `MigrationInProgress`. This
-//! storage item defines a [`Cursor`] for the current migration step.
+//! performing the actual migration, we set a custom storage item [`MigrationInProgress`].
+//! This storage item defines a [`Cursor`] for the current migration step.
 //!
-//! If the `MigrationInProgress` storage item exists, it means a migration is in progress, and its
+//! If the [`MigrationInProgress`] storage item exists, it means a migration is in progress, and its
 //! value holds a cursor for the current migration step. These migration steps are executed during
 //! [`Hooks<BlockNumber>::on_idle`] or when the [`Pallet::migrate`] dispatchable is
 //! called.

From 6417dde5bd3b96b764aac92fcad014f51e17b330 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 13:54:17 +0200
Subject: [PATCH 21/42] Remove dup comment

---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 4b5f95df5ec81..d3c475df27434 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -175,9 +175,9 @@ mod private {
 pub trait MigrateSequence: private::Sealed {
 	/// Returns the range of versions that this migration can handle.
 	/// Migrations must be ordered by their versions with no gaps.
-	/// The following code will fail to compile:
 	///
 	/// The following code will fail to compile:
+	///
 	/// ```compile_fail
 	///     # use pallet_contracts::{NoopMigration, MigrateSequence};
 	/// 	let _ = <(NoopMigration<1>, NoopMigration<3>)>::VERSION_RANGE;

From e6bb63de1b7468c3652436f987eb534c63b2e25a Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:04:52 +0200
Subject: [PATCH 22/42] add doc for MigrationInProgress

---
 frame/contracts/src/lib.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 924ccf5a8633c..e008183cf1774 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -991,6 +991,8 @@ pub mod pallet {
 	pub(crate) type DeletionQueueCounter<T: Config> =
 		StorageValue<_, DeletionQueueManager<T>, ValueQuery>;
 
+	/// A migration can span across multiple blocks. This storage defines a cursor to track the
+	/// progress of the migration, enabling us to resume from the last completed position.
 	#[pallet::storage]
 	pub(crate) type MigrationInProgress<T: Config> =
 		StorageValue<_, migration::Cursor, OptionQuery>;

From 1841f2348bda131ad644f33ee1ac0b9d47cd361e Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:15:53 +0200
Subject: [PATCH 23/42] PR review remove duplicate asserts

---
 frame/contracts/src/migration/v9.rs | 2 --
 1 file changed, 2 deletions(-)

diff --git a/frame/contracts/src/migration/v9.rs b/frame/contracts/src/migration/v9.rs
index 2aed926e632bf..9f00f47da3886 100644
--- a/frame/contracts/src/migration/v9.rs
+++ b/frame/contracts/src/migration/v9.rs
@@ -140,8 +140,6 @@ impl<T: Config> MigrationStep for Migration<T> {
 			ensure!(module.initial == old.initial, "invalid initial");
 			ensure!(module.maximum == old.maximum, "invalid maximum");
 			ensure!(module.code == old.code, "invalid code");
-			ensure!(module.maximum == old.maximum, "invalid maximum");
-			ensure!(module.code == old.code, "invalid code");
 		}
 
 		Ok(())

From 0236ca0d75fbe655fe4df32d130e4cefcfaea7c0 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:16:18 +0200
Subject: [PATCH 24/42] simplify upper bound

---
 frame/contracts/src/benchmarking/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index dcfb3f841c02a..3e0540512e70b 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -237,7 +237,7 @@ benchmarks! {
 	// This benchmarks the v9 migration step. (update codeStorage)
 	#[pov_mode = Measured]
 	v9_migration_step {
-		let c in 0 .. Perbill::from_percent(49).mul_ceil(T::MaxCodeLen::get());
+		let c in 0 .. T::MaxCodeLen::get();
 		v9::store_old_dummy_code::<T>(c as usize);
 		let mut m = v9::Migration::<T>::default();
 	}: {

From 4686c0300be2c61b8f6103c64f8f50dc16292976 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:18:08 +0200
Subject: [PATCH 25/42] fix link

---
 frame/contracts/src/migration/v10.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index 8d5897d15caee..90bb12047d24f 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -16,7 +16,7 @@
 // limitations under the License.
 
 //! Don't rely on reserved balances keeping an account alive
-//! See <https://github.com/paritytech/substrate/pull/13370>.
+//! See <https://github.com/paritytech/substrate/pull/13369>.
 
 use crate::{
 	address::AddressGenerator,

From 5e029e1e29fe9f5e1f24f06576a65c6084eeabf6 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:18:41 +0200
Subject: [PATCH 26/42] typo

---
 frame/contracts/src/migration/v10.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index 90bb12047d24f..e138f5736ae73 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -188,7 +188,7 @@ impl<T: Config> MigrationStep for Migration<T> {
 
 			// Calculate the new base_deposit to store in the contract:
 			// Ideally: it should be the same as the old one
-			// Ideally, it should be at least 2xED (for the contract and deposit account).
+			// Ideally, it should be at least 2xED (for the contract and deposit accounts).
 			// It can't be more than the `new_deposit`.
 			let new_base_deposit = min(
 				max(contract.storage_base_deposit, min_balance.saturating_add(min_balance)),

From c7846be2dcae9fc784e3c2dcc23b85955b9e8b62 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:19:10 +0200
Subject: [PATCH 27/42] typo

---
 frame/contracts/src/migration/v10.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index e138f5736ae73..ffe4c1d590f8a 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -187,7 +187,7 @@ impl<T: Config> MigrationStep for Migration<T> {
 			});
 
 			// Calculate the new base_deposit to store in the contract:
-			// Ideally: it should be the same as the old one
+			// Ideally, it should be the same as the old one
 			// Ideally, it should be at least 2xED (for the contract and deposit accounts).
 			// It can't be more than the `new_deposit`.
 			let new_base_deposit = min(

From d4349fb7a28142fd3dbdac92deef23b126f72c4a Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 14:24:05 +0200
Subject: [PATCH 28/42] no unwrap()

---
 frame/contracts/src/migration/v10.rs | 4 ++--
 frame/contracts/src/migration/v11.rs | 3 ++-
 frame/contracts/src/migration/v9.rs  | 4 ++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index ffe4c1d590f8a..d3545340e43bf 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -240,8 +240,8 @@ impl<T: Config> MigrationStep for Migration<T> {
 
 	#[cfg(feature = "try-runtime")]
 	fn post_upgrade_step(state: Vec<u8>) -> Result<(), TryRuntimeError> {
-		let sample =
-			<Vec<(T::AccountId, old::ContractInfo<T>)> as Decode>::decode(&mut &state[..]).unwrap();
+		let sample = <Vec<(T::AccountId, old::ContractInfo<T>)> as Decode>::decode(&mut &state[..])
+			.expect("pre_upgrade_step provides a valid state; qed");
 
 		log::debug!(target: LOG_TARGET, "Validating sample of {} contracts", sample.len());
 		for (account, old_contract) in sample {
diff --git a/frame/contracts/src/migration/v11.rs b/frame/contracts/src/migration/v11.rs
index 59e4f5b2862c4..67740cfaf6c80 100644
--- a/frame/contracts/src/migration/v11.rs
+++ b/frame/contracts/src/migration/v11.rs
@@ -121,7 +121,8 @@ impl<T: Config> MigrationStep for Migration<T> {
 
 	#[cfg(feature = "try-runtime")]
 	fn post_upgrade_step(state: Vec<u8>) -> Result<(), TryRuntimeError> {
-		let len = <u32 as Decode>::decode(&mut &state[..]).unwrap();
+		let len = <u32 as Decode>::decode(&mut &state[..])
+			.expect("pre_upgrade_step provides a valid state; qed");
 		let counter = <DeletionQueueCounter<T>>::get();
 		ensure!(counter.insert_counter == len, "invalid insert counter");
 		ensure!(counter.delete_counter == 0, "invalid delete counter");
diff --git a/frame/contracts/src/migration/v9.rs b/frame/contracts/src/migration/v9.rs
index 9f00f47da3886..d50f79c72c3be 100644
--- a/frame/contracts/src/migration/v9.rs
+++ b/frame/contracts/src/migration/v9.rs
@@ -126,8 +126,8 @@ impl<T: Config> MigrationStep for Migration<T> {
 
 	#[cfg(feature = "try-runtime")]
 	fn post_upgrade_step(state: Vec<u8>) -> Result<(), TryRuntimeError> {
-		let sample =
-			<Vec<(CodeHash<T>, old::PrefabWasmModule)> as Decode>::decode(&mut &state[..]).unwrap();
+		let sample = <Vec<(CodeHash<T>, old::PrefabWasmModule)> as Decode>::decode(&mut &state[..])
+			.expect("pre_upgrade_step provides a valid state; qed");
 
 		log::debug!(target: LOG_TARGET, "Validating sample of {} contract codes", sample.len());
 		for (code_hash, old) in sample {

From 7511bac4ba870ab8f9d721eec89da4b303585d1d Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 15:17:09 +0200
Subject: [PATCH 29/42] correct log message

---
 frame/contracts/src/migration/v10.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index d3545340e43bf..61ff362e7c96b 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -181,7 +181,7 @@ impl<T: Config> MigrationStep for Migration<T> {
 			})
 			// If it fails we fallback to minting the ED.
 			.unwrap_or_else(|err| {
-				log::error!(target: LOG_TARGET, "Failed to transfer ED, reason: {:?}", err);
+				log::error!(target: LOG_TARGET, "Failed to transfer the base deposit, reason: {:?}", err);
 				T::Currency::deposit_creating(&deposit_account, min_balance);
 				min_balance
 			});

From 3545f04265a616c339142528e7488736d3782f75 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Fri, 9 Jun 2023 15:23:36 +0200
Subject: [PATCH 30/42] missing

---
 frame/contracts/src/migration.rs | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index bb21741edd549..d3c475df27434 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -541,36 +541,9 @@ mod test {
 	#[test]
 	fn is_upgrade_supported_works() {
 		type Migrations = (MockMigration<9>, MockMigration<10>, MockMigration<11>);
-<<<<<<< HEAD
 		assert!(Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(11)));
 		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(9), StorageVersion::new(11)));
 		assert!(!Migrations::is_upgrade_supported(StorageVersion::new(8), StorageVersion::new(12)));
-=======
-
-		[(1, 1), (8, 11), (9, 11)].into_iter().for_each(|(from, to)| {
-			assert!(
-				Migrations::is_upgrade_supported(
-					StorageVersion::new(from),
-					StorageVersion::new(to)
-				),
-				"{} -> {} is supported",
-				from,
-				to
-			)
-		});
-
-		[(1, 0), (0, 3), (7, 11), (8, 10)].into_iter().for_each(|(from, to)| {
-			assert!(
-				!Migrations::is_upgrade_supported(
-					StorageVersion::new(from),
-					StorageVersion::new(to)
-				),
-				"{} -> {} is not supported",
-				from,
-				to
-			)
-		});
->>>>>>> master
 	}
 
 	#[test]

From 08f84fbba78f4c76ae3c8402acdd9471ab4fdd68 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Mon, 12 Jun 2023 10:57:05 +0200
Subject: [PATCH 31/42] fix typo

---
 frame/contracts/src/benchmarking/mod.rs | 2 +-
 frame/contracts/src/migration/v10.rs    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index 3e0540512e70b..f671826dd1398 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -251,7 +251,7 @@ benchmarks! {
 			whitelisted_caller(), WasmModule::dummy(), vec![],
 		)?;
 
-		v10::store_old_contrat_info::<T>(contract.account_id.clone(), contract.info()?);
+		v10::store_old_contract_info::<T>(contract.account_id.clone(), contract.info()?);
 		let mut m = v10::Migration::<T>::default();
 	}: {
 		m.step();
diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index 61ff362e7c96b..d58a9479f2fb9 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -69,7 +69,7 @@ mod old {
 }
 
 #[cfg(feature = "runtime-benchmarks")]
-pub fn store_old_contrat_info<T: Config>(account: T::AccountId, info: crate::ContractInfo<T>) {
+pub fn store_old_contract_info<T: Config>(account: T::AccountId, info: crate::ContractInfo<T>) {
 	let info = old::ContractInfo {
 		trie_id: info.trie_id,
 		code_hash: info.code_hash,

From 85f334f6d95214460445c9100ae2aa66a3ec62e5 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Mon, 12 Jun 2023 12:21:00 +0200
Subject: [PATCH 32/42] PR comment

---
 frame/contracts/src/benchmarking/mod.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index f671826dd1398..be95294835a0e 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -277,15 +277,15 @@ benchmarks! {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
 
-	// This benchmarks the weight of executing 1 `NoopMigraton`
+	// This benchmarks the weight of dispatching migrate to executing 1 `NoopMigraton`
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();
 		<Migration::<T> as frame_support::traits::OnRuntimeUpgrade>::on_runtime_upgrade();
-		let origin: RawOrigin<<T as frame_system::Config>::AccountId> = RawOrigin::Signed(whitelisted_caller());
-	}: {
-		<Contracts<T>>::migrate(origin.into(), Weight::MAX).unwrap()
-	} verify {
+		let caller: T::AccountId = whitelisted_caller();
+		let origin = RawOrigin::Signed(caller.clone());
+	}: _(origin, Weight::MAX)
+	verify {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 1);
 	}
 

From 103d50c2a7dd38e0b168b3436ec93c3ae3167061 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Tue, 13 Jun 2023 13:17:05 +0200
Subject: [PATCH 33/42] Add example with single element tuple

---
 frame/contracts/src/lib.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 3df33ada47ea3..9a798c1a824dd 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -329,6 +329,13 @@ pub mod pallet {
 		/// # struct Runtime {};
 		/// type Migrations = (v9::Migration<Runtime>, v10::Migration<Runtime>, v11::Migration<Runtime>);
 		/// ```
+		///
+		/// If you have a single migration step, you can use a tuple with a single element:
+		/// ```
+		/// use pallet_contracts::migration::v9;
+		/// # struct Runtime {};
+		/// type Migrations = (v9::Migration<Runtime>,);
+		/// ```
 		type Migrations: MigrateSequence;
 	}
 

From dbb20d3accc0331eb40af0c842427bfeeb430240 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Tue, 13 Jun 2023 17:31:01 +0200
Subject: [PATCH 34/42] Improve migration message

---
 frame/contracts/src/migration.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index d3c475df27434..a8a559196e286 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -299,15 +299,13 @@ impl<T: Config> OnRuntimeUpgrade for Migration<T> {
 
 		log::debug!(
 			target: LOG_TARGET,
-			"{}: Range supported {:?}, range requested {:?}",
-			<Pallet<T>>::name(),
-			T::Migrations::VERSION_RANGE,
-			(storage_version, target_version)
+			"Requested migration of {} from {:?}(on-chain storage version) to {:?}(current storage version)",
+			<Pallet<T>>::name(), storage_version, target_version
 		);
 
 		ensure!(
 			T::Migrations::is_upgrade_supported(storage_version, target_version),
-			"Unsupported upgrade"
+			"Unsupported upgrade: VERSION_RANGE should be (on-chain storage version + 1, current storage version)"
 		);
 		Ok(Default::default())
 	}

From 3b3c179fd0fb3323aaf961443611300210a54c00 Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Thu, 15 Jun 2023 17:40:00 +0200
Subject: [PATCH 35/42] Update frame/contracts/src/benchmarking/mod.rs

Co-authored-by: Sasha Gryaznov <hi@agryaznov.com>
---
 frame/contracts/src/benchmarking/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/benchmarking/mod.rs b/frame/contracts/src/benchmarking/mod.rs
index be95294835a0e..0233405d10f08 100644
--- a/frame/contracts/src/benchmarking/mod.rs
+++ b/frame/contracts/src/benchmarking/mod.rs
@@ -277,7 +277,7 @@ benchmarks! {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
 
-	// This benchmarks the weight of dispatching migrate to executing 1 `NoopMigraton`
+	// This benchmarks the weight of dispatching migrate to execute 1 `NoopMigraton`
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();

From fc977cb2203ea68f00171f3841444328f73de1f3 Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Thu, 15 Jun 2023 17:40:44 +0200
Subject: [PATCH 36/42] Update frame/contracts/src/migration.rs

Co-authored-by: Sasha Gryaznov <hi@agryaznov.com>
---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index a8a559196e286..4348c2e290765 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -46,7 +46,7 @@
 //!
 //! When a migration starts and [`OnRuntimeUpgrade::on_runtime_upgrade`] is called, instead of
 //! performing the actual migration, we set a custom storage item [`MigrationInProgress`].
-//! This storage item defines a [`Cursor`] for the current migration step.
+//! This storage item defines a [`Cursor`] for the current migration.
 //!
 //! If the [`MigrationInProgress`] storage item exists, it means a migration is in progress, and its
 //! value holds a cursor for the current migration step. These migration steps are executed during

From d45d5700cf2fecac7c9f099270cea77bd52a5bed Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Thu, 15 Jun 2023 17:46:23 +0200
Subject: [PATCH 37/42] Update frame/contracts/src/migration.rs

Co-authored-by: Sasha Gryaznov <hi@agryaznov.com>
---
 frame/contracts/src/migration.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 4348c2e290765..65ddc2b439d21 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -173,7 +173,7 @@ mod private {
 /// The sequence must be defined by a tuple of migrations, each of which must implement the
 /// `Migrate` trait. Migrations must be ordered by their versions with no gaps.
 pub trait MigrateSequence: private::Sealed {
-	/// Returns the range of versions that this migration can handle.
+	/// Returns the range of versions that this migrations sequence can handle.
 	/// Migrations must be ordered by their versions with no gaps.
 	///
 	/// The following code will fail to compile:

From 9d5b6b8afc1bb2a6c1f2fee1185cdafba70ca4ba Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Thu, 15 Jun 2023 20:47:07 +0200
Subject: [PATCH 38/42] use saturating_accrue instead of +=

---
 frame/contracts/src/migration.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 65ddc2b439d21..641a059e14695 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -67,6 +67,7 @@ use frame_support::{
 	pallet_prelude::*,
 	traits::{ConstU32, OnRuntimeUpgrade},
 };
+use sp_runtime::Saturating;
 use sp_std::marker::PhantomData;
 
 #[cfg(feature = "try-runtime")]
@@ -481,7 +482,7 @@ impl MigrateSequence for Tuple {
 					let mut steps_done = 0;
 					while weight_left.all_gt(max_weight) {
 						let (finished, weight) = migration.step();
-						steps_done += 1;
+						steps_done.saturating_accrue(1);
 						weight_left.saturating_reduce(weight);
 						if matches!(finished, IsFinished::Yes) {
 							return StepResult::Completed{ steps_done }

From fe412a7c63712599d465460edf50c4816977e6a2 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Thu, 15 Jun 2023 20:58:03 +0200
Subject: [PATCH 39/42] add more doc

---
 frame/contracts/src/migration.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 641a059e14695..00f9bf354be0a 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -84,7 +84,8 @@ fn invalid_version(version: StorageVersion) -> ! {
 	panic!("Required migration {version:?} not supported by this runtime. This is a bug.");
 }
 
-/// The cursor used to store the state of the current migration step.
+/// The cursor used to encode the position (usually the last iterated key) of the current migration
+/// step.
 pub type Cursor = BoundedVec<u8, ConstU32<1024>>;
 
 /// IsFinished describes whether a migration is finished or not.

From 8643fcdbeade3022056454751af0b6de4d746c51 Mon Sep 17 00:00:00 2001
From: PG Herveou <pgherveou@gmail.com>
Date: Tue, 20 Jun 2023 11:45:39 +0200
Subject: [PATCH 40/42] Contracts: Better migration types (#14418)

---
 frame/contracts/src/migration/v10.rs | 18 ++++++++++--------
 frame/contracts/src/migration/v9.rs  | 15 ++++++---------
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/frame/contracts/src/migration/v10.rs b/frame/contracts/src/migration/v10.rs
index d58a9479f2fb9..75d794a6d8167 100644
--- a/frame/contracts/src/migration/v10.rs
+++ b/frame/contracts/src/migration/v10.rs
@@ -42,7 +42,7 @@ use sp_core::hexdisplay::HexDisplay;
 #[cfg(feature = "try-runtime")]
 use sp_runtime::TryRuntimeError;
 use sp_runtime::{traits::Zero, Perbill, Saturating};
-use sp_std::{marker::PhantomData, ops::Deref, prelude::*};
+use sp_std::{ops::Deref, prelude::*};
 
 mod old {
 	use super::*;
@@ -109,8 +109,7 @@ pub struct ContractInfo<T: Config> {
 
 #[derive(Encode, Decode, MaxEncodedLen, DefaultNoBound)]
 pub struct Migration<T: Config> {
-	last_key: Option<BoundedVec<u8, ConstU32<256>>>,
-	_phantom: PhantomData<T>,
+	last_account: Option<T::AccountId>,
 }
 
 #[storage_alias]
@@ -125,8 +124,10 @@ impl<T: Config> MigrationStep for Migration<T> {
 	}
 
 	fn step(&mut self) -> (IsFinished, Weight) {
-		let mut iter = if let Some(last_key) = self.last_key.take() {
-			old::ContractInfoOf::<T>::iter_from(last_key.to_vec())
+		let mut iter = if let Some(last_account) = self.last_account.take() {
+			old::ContractInfoOf::<T>::iter_from(old::ContractInfoOf::<T>::hashed_key_for(
+				last_account,
+			))
 		} else {
 			old::ContractInfoOf::<T>::iter()
 		};
@@ -135,9 +136,6 @@ impl<T: Config> MigrationStep for Migration<T> {
 			let min_balance = Pallet::<T>::min_balance();
 			log::debug!(target: LOG_TARGET, "Account: 0x{} ", HexDisplay::from(&account.encode()));
 
-			// Store last key for next migration step
-			self.last_key = Some(iter.last_raw_key().to_vec().try_into().unwrap());
-
 			// Get the new deposit account address
 			let deposit_account: DepositAccount<T> =
 				DepositAccount(T::AddressGenerator::deposit_address(&account));
@@ -223,6 +221,10 @@ impl<T: Config> MigrationStep for Migration<T> {
 			};
 
 			ContractInfoOf::<T>::insert(&account, new_contract_info);
+
+			// Store last key for next migration step
+			self.last_account = Some(account);
+
 			(IsFinished::No, T::WeightInfo::v10_migration_step())
 		} else {
 			log::debug!(target: LOG_TARGET, "Done Migrating contract info");
diff --git a/frame/contracts/src/migration/v9.rs b/frame/contracts/src/migration/v9.rs
index d50f79c72c3be..e6c6642955642 100644
--- a/frame/contracts/src/migration/v9.rs
+++ b/frame/contracts/src/migration/v9.rs
@@ -23,12 +23,10 @@ use crate::{
 	CodeHash, Config, Determinism, Pallet, Weight, LOG_TARGET,
 };
 use codec::{Decode, Encode};
-use frame_support::{
-	codec, pallet_prelude::*, storage_alias, BoundedVec, DefaultNoBound, Identity,
-};
+use frame_support::{codec, pallet_prelude::*, storage_alias, DefaultNoBound, Identity};
 #[cfg(feature = "try-runtime")]
 use sp_runtime::TryRuntimeError;
-use sp_std::{marker::PhantomData, prelude::*};
+use sp_std::prelude::*;
 
 mod old {
 	use super::*;
@@ -79,8 +77,7 @@ type CodeStorage<T: Config> = StorageMap<Pallet<T>, Identity, CodeHash<T>, Prefa
 
 #[derive(Encode, Decode, MaxEncodedLen, DefaultNoBound)]
 pub struct Migration<T: Config> {
-	last_key: Option<BoundedVec<u8, ConstU32<256>>>,
-	_phantom: PhantomData<T>,
+	last_code_hash: Option<CodeHash<T>>,
 }
 
 impl<T: Config> MigrationStep for Migration<T> {
@@ -91,8 +88,8 @@ impl<T: Config> MigrationStep for Migration<T> {
 	}
 
 	fn step(&mut self) -> (IsFinished, Weight) {
-		let mut iter = if let Some(last_key) = self.last_key.take() {
-			old::CodeStorage::<T>::iter_from(last_key.to_vec())
+		let mut iter = if let Some(last_key) = self.last_code_hash.take() {
+			old::CodeStorage::<T>::iter_from(old::CodeStorage::<T>::hashed_key_for(last_key))
 		} else {
 			old::CodeStorage::<T>::iter()
 		};
@@ -108,7 +105,7 @@ impl<T: Config> MigrationStep for Migration<T> {
 				determinism: Determinism::Enforced,
 			};
 			CodeStorage::<T>::insert(key, module);
-			self.last_key = Some(iter.last_raw_key().to_vec().try_into().unwrap());
+			self.last_code_hash = Some(key);
 			(IsFinished::No, T::WeightInfo::v9_migration_step(len))
 		} else {
 			log::debug!(target: LOG_TARGET, "No more contracts code to migrate");

From 7a2c272bd9a4e133f60215a9b7fc0aa79898c9b9 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Tue, 20 Jun 2023 11:56:56 +0200
Subject: [PATCH 41/42] Add explicit error, if try-runtime runs a noop
 migration

---
 frame/contracts/src/migration.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/frame/contracts/src/migration.rs b/frame/contracts/src/migration.rs
index 272ea7fad280d..5da1bb70a6204 100644
--- a/frame/contracts/src/migration.rs
+++ b/frame/contracts/src/migration.rs
@@ -306,6 +306,11 @@ impl<T: Config, const TEST_ALL_STEPS: bool> OnRuntimeUpgrade for Migration<T, TE
 		let storage_version = <Pallet<T>>::on_chain_storage_version();
 		let target_version = <Pallet<T>>::current_storage_version();
 
+		ensure!(
+			storage_version != target_version,
+			"No upgrade: Please remove this migration from your runtime upgrade configuration."
+		);
+
 		log::debug!(
 			target: LOG_TARGET,
 			"Requested migration of {} from {:?}(on-chain storage version) to {:?}(current storage version)",

From 030554d5b5c8664b7a79e1fea678142578d48b04 Mon Sep 17 00:00:00 2001
From: pgherveou <pgherveou@gmail.com>
Date: Tue, 20 Jun 2023 12:01:52 +0200
Subject: [PATCH 42/42] use mut remaining_weight

---
 frame/contracts/src/lib.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs
index 2d5cba082ec6e..0b765a2e89956 100644
--- a/frame/contracts/src/lib.rs
+++ b/frame/contracts/src/lib.rs
@@ -341,9 +341,8 @@ pub mod pallet {
 
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
-		fn on_idle(_block: T::BlockNumber, remaining_weight: Weight) -> Weight {
+		fn on_idle(_block: T::BlockNumber, mut remaining_weight: Weight) -> Weight {
 			use migration::MigrateResult::*;
-			let mut remaining_weight = remaining_weight;
 
 			loop {
 				let (result, weight) = Migration::<T>::migrate(remaining_weight);