feat: Blockhash returning expected value

crates/script/src/simulate.rs

@@ -230,7 +230,8 @@ impl PreSimulationState {
             .into_iter()
             .map(|btx| {
                 let mut tx = TransactionWithMetadata::from_tx_request(btx.transaction);
-                tx.zk = btx.zk_tx.map(|metadata| ZkTransaction { factory_deps: metadata.factory_deps });
+                tx.zk =
+                    btx.zk_tx.map(|metadata| ZkTransaction { factory_deps: metadata.factory_deps });
                 tx.rpc = btx.rpc.expect("missing broadcastable tx rpc url");
                 tx
             })

crates/zksync/core/src/vm/runner.rs

@@ -63,13 +63,29 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     let call_ctx = CallContext {
         tx_caller: env.tx.caller,
         msg_sender: env.tx.caller,
         contract: transact_to.to_address(),
         delegate_as: None,
         block_number: env.block.number,
         block_timestamp: env.block.timestamp,
+        blockhashes,
         block_basefee: min(max_fee_per_gas.to_ru256(), env.block.basefee),
         is_create,
         is_static: false,
@@ -151,6 +167,21 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     let call_ctx = CallContext {
         tx_caller: ecx.env.tx.caller,
         msg_sender: call.caller,
@@ -159,6 +190,7 @@ where
         block_number: ecx.env.block.number,
         block_timestamp: ecx.env.block.timestamp,
         block_basefee: min(max_fee_per_gas.to_ru256(), ecx.env.block.basefee),
+        blockhashes,
         is_create: true,
         is_static: false,
     };
@@ -201,6 +233,21 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     // address and caller are specific to the type of call:
     // Call | StaticCall => { address: to, caller: contract.address }
     // CallCode          => { address: contract.address, caller: contract.address }
@@ -215,6 +262,7 @@ where
         },
         block_number: ecx.env.block.number,
         block_timestamp: ecx.env.block.timestamp,
+        blockhashes,
         block_basefee: min(max_fee_per_gas.to_ru256(), ecx.env.block.basefee),
         is_create: false,
         is_static: call.is_static,

crates/zksync/core/src/vm/tracer.rs

@@ -109,6 +109,9 @@ pub struct CallContext {
     pub is_create: bool,
     /// Whether the current call is a static call.
     pub is_static: bool,
+    /// L1 blockhashes to ensure consistency when returning environment data in L2, similar to
+    /// other cases (e.g., Block number, Block timestamp)
+    pub blockhashes: HashMap<alloy_primitives::U256, alloy_primitives::FixedBytes<32>>,
 }
 
 /// A tracer to allow for foundry-specific functionality.
@@ -302,8 +305,11 @@ impl<S: Send, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CheatcodeTracer
             if current.code_address == SYSTEM_CONTEXT_ADDRESS &&
                 calldata.starts_with(&SELECTOR_BLOCK_HASH)
             {
-                self.farcall_handler.set_immediate_return(rU256::ZERO.to_be_bytes_vec());
-                return
+                let index = U256::from_big_endian(&calldata[calldata.len() - 4..]);
+                if let Some(blockhash) = self.call_context.blockhashes.get(&index.to_ru256()) {
+                    self.farcall_handler.set_immediate_return(blockhash.to_vec());
+                    return;
+                }
             }
         }