contracts: Add test to verify unique trie ids (#10914)

* Add test to verify unique trie ids

* Rename trie_seed to nonce

* Rename AccountCounter -> Nonce

* fmt

substrate/frame/contracts/src/migration.rs

@@ -19,6 +19,7 @@ use crate::{BalanceOf, CodeHash, Config, Pallet, TrieId, Weight};
 use codec::{Decode, Encode};
 use frame_support::{
 	codec, generate_storage_alias,
+	pallet_prelude::*,
 	storage::migration,
 	traits::{Get, PalletInfoAccess},
 	Identity, Twox64Concat,
@@ -47,6 +48,11 @@ pub fn migrate<T: Config>() -> Weight {
 		StorageVersion::new(6).put::<Pallet<T>>();
 	}
 
+	if version < 7 {
+		weight = weight.saturating_add(v7::migrate::<T>());
+		StorageVersion::new(7).put::<Pallet<T>>();
+	}
+
 	weight
 }
 
@@ -249,3 +255,21 @@ mod v6 {
 		weight
 	}
 }
+
+/// Rename `AccountCounter` to `Nonce`.
+mod v7 {
+	use super::*;
+
+	pub fn migrate<T: Config>() -> Weight {
+		generate_storage_alias!(
+			Contracts,
+			AccountCounter => Value<u64, ValueQuery>
+		);
+		generate_storage_alias!(
+			Contracts,
+			Nonce => Value<u64, ValueQuery>
+		);
+		Nonce::set(AccountCounter::take());
+		T::DbWeight::get().reads_writes(1, 2)
+	}
+}