fix(provider): explicitly use state based on the block number (#330)

Author: kariy

bin/katana/tests/db_prune.rs

@@ -91,7 +91,7 @@ fn prune_keep_last_n_blocks(db: TempDb) {
     // block -> (classes root, contracts root)
     let mut historical_roots_reg = HashMap::new();
 
-    for num in 1..=latest_block {
+    for num in 0..=latest_block {
         let (classes_root, contracts_root) = historical_roots(&provider, num).unwrap();
         assert!(classes_root != Felt::ZERO, "classes root for block {num} cannot be zero");
         assert!(contracts_root != Felt::ZERO, "contracts root for block {num} cannot be zero");
@@ -148,7 +148,7 @@ fn prune_keep_last_n_blocks_exceeds_available(db: TempDb) {
     let mut historical_roots_reg = HashMap::new();
 
     // Verify all historical states are accessible before pruning
-    for num in 1..=latest_block {
+    for num in 0..=latest_block {
         let (classes_root, contracts_root) = historical_roots(&provider, num).unwrap();
         assert!(classes_root != Felt::ZERO, "classes root for block {num} cannot be zero");
         assert!(contracts_root != Felt::ZERO, "contracts root for block {num} cannot be zero");
@@ -180,7 +180,7 @@ fn prune_keep_last_n_blocks_exceeds_available(db: TempDb) {
     let (final_classes_root, final_contracts_root) = latest_roots(&provider).unwrap();
 
     // Verify that NO pruning occurred - all historical states should still be accessible
-    for num in 1..=latest_block {
+    for num in 0..=latest_block {
         let (classes_root, contracts_root) = historical_roots(&provider, num).unwrap();
         let (expected_classes_root, expected_contracts_root) =
             historical_roots_reg.get(&num).unwrap();

bin/katana/tests/fixtures.rs

@@ -68,7 +68,7 @@ pub fn db() -> TempDb {
 fn populate_db(db: &TempDb) {
     let provider = db.provider_rw();
 
-    for num in 1..=15u64 {
+    for num in 0..=15u64 {
         let mut classes = BTreeMap::new();
 
         let mut declared_classes = BTreeMap::new();

crates/storage/provider/provider/src/providers/db/trie.rs

@@ -85,8 +85,14 @@ impl<Db: Database> TrieWriter for DbProvider<Db> {
                         let storage_root = storage_trie.root();
                         leaf.storage_root = Some(storage_root);
 
-                        let latest_state = self.latest()?;
-                        let leaf_hash = contract_state_leaf_hash(latest_state, &address, &leaf);
+                        let state = if block_number == 0 {
+                            self.latest()? // this will just default to an empty state
+                        } else {
+                            self.historical((block_number - 1).into())?
+                                .expect("historical state should exist")
+                        };
+
+                        let leaf_hash = contract_state_leaf_hash(state, &address, &leaf);
 
                         Ok((address, leaf_hash))
                     })