feat(fw): add optional verify_sync flag to hive blockchain tests

docs/CHANGELOG.md

@@ -22,6 +22,7 @@ Test fixtures for use by clients are available for each release on the [Github r
 - 🔀 Locally calculate state root for the genesis blocks in the blockchain tests instead of calling t8n ([#450](https://github.com/ethereum/execution-spec-tests/pull/450)).
 - 🐞 Fix bug that causes an exception during test collection because the fork parameter contains `None` ([#452](https://github.com/ethereum/execution-spec-tests/pull/452)).
 - ✨ The `_info` field in the test fixtures now contains a `hash` field, which is the hash of the test fixture, and a `hasher` script has been added which prints and performs calculations on top of the hashes of all fixtures (see `hasher -h`) ([#454](https://github.com/ethereum/execution-spec-tests/pull/454)).
+- ✨ Adds an optional `verify_sync` field to hive blockchain tests (EngineAPI). When set to true a second client attempts to sync to the first client that executed the tests.([#431](https://github.com/ethereum/execution-spec-tests/pull/431)).
 
 ### 🔧 EVM Tools
 

src/ethereum_test_tools/spec/blockchain/blockchain_test.py

@@ -101,6 +101,7 @@ class BlockchainTest(BaseTest):
     post: Mapping
     blocks: List[Block]
     genesis_environment: Environment = field(default_factory=Environment)
+    verify_sync: Optional[bool] = None
     tag: str = ""
     chain_id: int = 1
 
@@ -393,6 +394,7 @@ def make_hive_fixture(
         pre, _, genesis = self.make_genesis(t8n, fork)
         alloc = to_json(pre)
         env = environment_from_parent_header(genesis)
+        head_hash = genesis.hash
 
         for block in self.blocks:
             header, _, txs, new_alloc, new_env = self.generate_block_data(
@@ -412,20 +414,50 @@ def make_hive_fixture(
                 if block.exception is None:
                     alloc = new_alloc
                     env = apply_new_parent(env, header)
+                    head_hash = header.hash
         fcu_version = fork.engine_forkchoice_updated_version(header.number, header.timestamp)
         assert (
             fcu_version is not None
         ), "A hive fixture was requested but no forkchoice update is defined. The framework should"
         " never try to execute this test case."
 
         self.verify_post_state(t8n, alloc)
+
+        sync_payload: Optional[FixtureEngineNewPayload] = None
+        if self.verify_sync:
+            # Test is marked for syncing verification.
+            assert (
+                genesis.hash != head_hash
+            ), "Invalid payload tests negative test via sync is not supported yet."
+
+            # Most clients require the header to start the sync process, so we create an empty
+            # block on top of the last block of the test to send it as new payload and trigger the
+            # sync process.
+            sync_header, _, _, _, _ = self.generate_block_data(
+                t8n=t8n,
+                fork=fork,
+                block=Block(),
+                previous_env=env,
+                previous_alloc=alloc,
+                eips=eips,
+            )
+            sync_payload = FixtureEngineNewPayload.from_fixture_header(
+                fork=fork,
+                header=sync_header,
+                transactions=[],
+                withdrawals=[],
+                validation_error=None,
+                error_code=None,
+            )
+
         return HiveFixture(
             fork=self.network_info(fork, eips),
             genesis=genesis,
             payloads=fixture_payloads,
             fcu_version=fcu_version,
             pre_state=pre,
             post_state=alloc_to_accounts(alloc),
+            sync_payload=sync_payload,
             name=self.tag,
         )
 

src/ethereum_test_tools/spec/blockchain/types.py

@@ -1122,6 +1122,13 @@ class HiveFixture(FixtureCommon):
             name="engineFcuVersion",
         ),
     )
+    sync_payload: Optional[FixtureEngineNewPayload] = field(
+        default=None,
+        json_encoder=JSONEncoder.Field(
+            name="syncPayload",
+            to_json=True,
+        ),
+    )
     pre_state: Mapping[str, Account] = field(
         json_encoder=JSONEncoder.Field(
             name="pre",

whitelist.txt

@@ -81,6 +81,7 @@ eip
 eips
 EIPs
 endianness
+EngineAPI
 enum
 env
 eof