forks: Add blob_gas_per_blob

Author: marioevz

src/ethereum_test_forks/base_fork.py

@@ -143,6 +143,14 @@ def header_beacon_root_required(cls, block_number: int, timestamp: int) -> bool:
         """
         pass
 
+    @classmethod
+    @abstractmethod
+    def blob_gas_per_blob(cls, block_number: int, timestamp: int) -> int:
+        """
+        Returns the amount of blob gas used per each blob for a given fork.
+        """
+        pass
+
     @classmethod
     @abstractmethod
     def get_reward(cls, block_number: int = 0, timestamp: int = 0) -> int:

src/ethereum_test_forks/forks/forks.py

@@ -72,6 +72,13 @@ def header_blob_gas_used_required(cls, block_number: int = 0, timestamp: int = 0
         """
         return False
 
+    @classmethod
+    def blob_gas_per_blob(cls, block_number: int, timestamp: int) -> int:
+        """
+        Returns the amount of blob gas used per each blob for a given fork.
+        """
+        return 0
+
     @classmethod
     def engine_new_payload_version(
         cls, block_number: int = 0, timestamp: int = 0
@@ -370,6 +377,13 @@ def header_beacon_root_required(cls, block_number: int = 0, timestamp: int = 0)
         """
         return True
 
+    @classmethod
+    def blob_gas_per_blob(cls, block_number: int, timestamp: int) -> int:
+        """
+        Blobs are enabled started from Cancun.
+        """
+        return 2**17
+
     @classmethod
     def tx_types(cls, block_number: int = 0, timestamp: int = 0) -> List[int]:
         """

src/ethereum_test_tools/spec/blockchain/blockchain_test.py

@@ -79,6 +79,15 @@ def apply_new_parent(env: Environment, new_parent: FixtureHeader) -> "Environmen
     return env
 
 
+def count_blobs(txs: List[Transaction]) -> int:
+    """
+    Returns the number of blobs in a list of transactions.
+    """
+    return sum(
+        [len(tx.blob_versioned_hashes) for tx in txs if tx.blob_versioned_hashes is not None]
+    )
+
+
 @dataclass(kw_only=True)
 class BlockchainTest(BaseTest):
     """
@@ -229,6 +238,15 @@ def generate_block_data(
             environment=env,
         )
 
+        # One special case of the invalid transactions is the blob gas used, since this value
+        # is not included in the transition tool result, but it is included in the block header,
+        # and some clients check it before executing the block by simply counting the type-3 txs,
+        # we need to set the correct value by default.
+        if (
+            blob_gas_per_blob := fork.blob_gas_per_blob(Number(env.number), Number(env.timestamp))
+        ) > 0:
+            header.blob_gas_used = blob_gas_per_blob * count_blobs(txs)
+
         if block.header_verify is not None:
             # Verify the header after transition tool processing.
             header.verify(block.header_verify)