tests: dynamic target blob count for 4844 tests.

tests/cancun/eip4844_blobs/spec.py

@@ -4,6 +4,7 @@
 from dataclasses import dataclass
 from hashlib import sha256
 from typing import Optional
+from ethereum_test_forks import Fork, Cancun
 
 from ethereum_test_tools import Transaction
 
@@ -62,6 +63,16 @@ class Spec:
     HASH_OPCODE_BYTE = 0x49
     HASH_GAS_COST = 3
 
+    @classmethod
+    def target_blob_gas_per_block(cls, fork: Optional[Fork] = Cancun, cl_target_blob_count: Optional[int] = None) -> int:
+        """
+        Returns the target blob gas per block, using a dynamic target for forks after Cancun.
+        For Cancun the target blob count is 3, hence the blob gas per block is 393216.
+        """
+        if fork and fork > Cancun and cl_target_blob_count is not None:
+                return cl_target_blob_count * cls.GAS_PER_BLOB
+        return Spec.TARGET_BLOB_GAS_PER_BLOCK
+
     @classmethod
     def kzg_to_versioned_hash(
         cls,
@@ -99,10 +110,10 @@ def calc_excess_blob_gas(cls, parent: BlockHeaderBlobGasFields) -> int:
         Calculate the excess blob gas for a block given the excess blob gas
         and blob gas used from the parent block header.
         """
-        if parent.excess_blob_gas + parent.blob_gas_used < cls.TARGET_BLOB_GAS_PER_BLOCK:
+        if parent.excess_blob_gas + parent.blob_gas_used < cls.target_blob_gas_per_block(): 
             return 0
         else:
-            return parent.excess_blob_gas + parent.blob_gas_used - cls.TARGET_BLOB_GAS_PER_BLOCK
+            return parent.excess_blob_gas + parent.blob_gas_used - cls.target_blob_gas_per_block()
 
     @classmethod
     def get_total_blob_gas(cls, tx: Transaction) -> int:
@@ -124,7 +135,6 @@ def get_blob_gasprice(cls, *, excess_blob_gas: int) -> int:
             cls.BLOB_GASPRICE_UPDATE_FRACTION,
         )
 
-
 @dataclass(frozen=True)
 class SpecHelpers:
     """
@@ -146,7 +156,7 @@ def target_blobs_per_block(cls) -> int:
         """
         Returns the target number of blobs per block.
         """
-        return Spec.TARGET_BLOB_GAS_PER_BLOCK // Spec.GAS_PER_BLOB
+        return Spec.target_blob_gas_per_block() // Spec.GAS_PER_BLOB
 
     @classmethod
     def calc_excess_blob_gas_from_blob_count(
@@ -180,4 +190,7 @@ def get_min_excess_blobs_for_blob_gas_price(cls, blob_gas_price: int) -> int:
         """
         Gets the minimum required excess blobs to get a given blob gas cost in a block
         """
-        return cls.get_min_excess_blob_gas_for_blob_gas_price(blob_gas_price) // Spec.GAS_PER_BLOB
+        return (
+            cls.get_min_excess_blob_gas_for_blob_gas_price(blob_gas_price)
+            // Spec.GAS_PER_BLOB
+        )