feat(tests): Additional cases for BLOCKCHASH

Author: pdobacz

docs/CHANGELOG.md

@@ -29,6 +29,7 @@ Test fixtures for use by clients are available for each release on the [Github r
 - ✨ Expand cases to test *CALL opcodes causing OOG ([#1703](https://github.com/ethereum/execution-specs/pull/1703)).
 - ✨ Add tests for `modexp` and `ripemd` precompiled contracts ([#1691](https://github.com/ethereum/execution-specs/pull/1691)).
 - ✨ Add `ecrecover` precompile tests originating form `evmone` unittests ([#1685](https://github.com/ethereum/execution-specs/pull/1685)).
+- ✨ Add stack overflow tests and expand `BLOCKHASH` tests ([#1728](https://github.com/ethereum/execution-specs/pull/1728)).
 
 ## [v5.3.0](https://github.com/ethereum/execution-spec-tests/releases/tag/v5.3.0) - 2025-10-09
 

tests/frontier/opcodes/test_blockhash.py

@@ -10,11 +10,19 @@
     Storage,
     Transaction,
 )
+from execution_testing.forks import Byzantium
+from execution_testing.forks.helpers import Fork
 
 
 @pytest.mark.valid_from("Frontier")
+@pytest.mark.parametrize(
+    "first_block", ["none", "empty", "with_tx", "over_256"]
+)
 def test_genesis_hash_available(
-    blockchain_test: BlockchainTestFiller, pre: Alloc
+    blockchain_test: BlockchainTestFiller,
+    pre: Alloc,
+    fork: Fork,
+    first_block: str,
 ) -> None:
     """
     Verify BLOCKHASH returns genesis and block 1 hashes.
@@ -29,45 +37,58 @@ def test_genesis_hash_available(
     Bug context: revm blockchaintest runner wasn't inserting block_hashes,
     causing failures in tests with BLOCKHASH-derived addresses.
     """
-    storage = Storage()
+    Storage()
 
     # Store ISZERO(BLOCKHASH(0)) and ISZERO(BLOCKHASH(1))
     # Both should be 0 (false) if hashes exist
-    code = Op.SSTORE(
-        storage.store_next(0), Op.ISZERO(Op.BLOCKHASH(0))
-    ) + Op.SSTORE(storage.store_next(0), Op.ISZERO(Op.BLOCKHASH(1)))
+    code = Op.SSTORE(0, Op.ISZERO(Op.BLOCKHASH(0))) + Op.SSTORE(
+        1, Op.ISZERO(Op.BLOCKHASH(1))
+    )
 
     contract = pre.deploy_contract(code=code)
     sender = pre.fund_eoa()
 
-    blocks = [
-        Block(
-            txs=[
-                Transaction(
-                    sender=sender,
-                    to=contract,
-                    gas_limit=100_000,
-                    protected=False,
-                )
-            ]
-        ),
-        Block(
-            txs=[
-                Transaction(
-                    sender=sender,
-                    to=contract,
-                    gas_limit=100_000,
-                    protected=False,
-                )
-            ]
-        ),
-    ]
+    blocks = (
+        [
+            Block(
+                txs=[
+                    Transaction(
+                        sender=sender,
+                        to=contract,
+                        gas_limit=100_000,
+                        protected=fork >= Byzantium,
+                    )
+                ]
+            )
+        ]
+        if first_block == "with_tx"
+        else [Block()]
+        if first_block == "empty"
+        else [Block()] * 256
+        if first_block == "over_256"
+        else []
+    ) + (
+        [
+            Block(
+                txs=[
+                    Transaction(
+                        sender=sender,
+                        to=contract,
+                        gas_limit=100_000,
+                        protected=fork >= Byzantium,
+                    )
+                ]
+            )
+        ]
+    )
 
     post = {
         contract: Account(
             storage={
-                0: 0,  # ISZERO(BLOCKHASH(0)) = 0 (genesis hash exists)
-                1: 0,  # ISZERO(BLOCKHASH(1)) = 0 (block 1 hash exists)
+                # ISZERO(BLOCKHASH(0)) = 0 (genesis hash exists)
+                0: 1 if first_block == "over_256" else 0,
+                # ISZERO(BLOCKHASH(1)) = 0 (if block 1 hash exists)
+                1: 1 if first_block == "none" else 0,
             }
         )
     }