From b49c5b043cbb5d1b7ca7ec9a83ba503feba11782 Mon Sep 17 00:00:00 2001
From: spencer-tb <spencer@spencertaylorbrown.uk>
Date: Sun, 28 Jan 2024 19:12:29 +0700
Subject: [PATCH] feat(tests): Add blob gas subtraction order tests.

---
 tests/cancun/eip4844_blobs/test_blob_txs.py | 84 ++++++++++++++++++++-
 1 file changed, 82 insertions(+), 2 deletions(-)

diff --git a/tests/cancun/eip4844_blobs/test_blob_txs.py b/tests/cancun/eip4844_blobs/test_blob_txs.py
index b5f5eee5b5..2a4f98fe6b 100644
--- a/tests/cancun/eip4844_blobs/test_blob_txs.py
+++ b/tests/cancun/eip4844_blobs/test_blob_txs.py
@@ -207,10 +207,28 @@ def total_account_minimum_balance(  # noqa: D103
     Calculates the minimum balance required for the account to be able to send
     the transactions in the block of the test.
     """
+    minimum_cost = 0
+    for tx_blob_count in [len(x) for x in blob_hashes_per_tx]:
+        blob_cost = tx_max_fee_per_blob_gas * Spec.GAS_PER_BLOB * tx_blob_count
+        minimum_cost += (tx_gas * tx_max_fee_per_gas) + tx_value + blob_cost
+    return minimum_cost
+
+
+@pytest.fixture
+def total_account_transactions_fee(  # noqa: D103
+    tx_gas: int,
+    tx_value: int,
+    block_fee_per_gas: int,
+    blob_gasprice: int,
+    blob_hashes_per_tx: List[List[bytes]],
+) -> int:
+    """
+    Calculates the actual fee for the blob transactions in the block of the test.
+    """
     total_cost = 0
     for tx_blob_count in [len(x) for x in blob_hashes_per_tx]:
-        data_cost = tx_max_fee_per_blob_gas * Spec.GAS_PER_BLOB * tx_blob_count
-        total_cost += (tx_gas * tx_max_fee_per_gas) + tx_value + data_cost
+        blob_cost = blob_gasprice * Spec.GAS_PER_BLOB * tx_blob_count
+        total_cost += (tx_gas * block_fee_per_gas) + tx_value + blob_cost
     return total_cost
 
 
@@ -896,6 +914,68 @@ def test_sufficient_balance_blob_tx_pre_fund_tx(
     )
 
 
+@pytest.mark.parametrize(
+    "tx_access_list",
+    [[], [AccessList(address=100, storage_keys=[100, 200])]],
+    ids=["no_access_list", "access_list"],
+)
+@pytest.mark.parametrize("tx_max_fee_per_gas", [7, 14])
+@pytest.mark.parametrize("tx_value", [0, 1])
+@pytest.mark.parametrize(
+    "tx_calldata",
+    [b"", b"\x01"],
+    ids=["no_calldata", "single_non_zero_byte_calldata"],
+)
+@pytest.mark.parametrize("tx_max_fee_per_blob_gas", [1, 100])
+@pytest.mark.parametrize(
+    "tx_gas", [500_000], ids=[""]
+)  # Increase gas to account for contract code
+@pytest.mark.parametrize(
+    "mid_tx_send_amount", [100]
+)  # Amount sent by the contract to the sender mid execution
+@pytest.mark.valid_from("Cancun")
+def test_blob_gas_subtraction_tx(
+    state_test: StateTestFiller,
+    state_env: Environment,
+    pre: Dict,
+    txs: List[Transaction],
+    destination_account: str,
+    mid_tx_send_amount: int,
+    total_account_transactions_fee: int,
+):
+    """
+    Check that the blob gas fee for a transaction is subtracted from the sender balance before the
+    transaction is executed, including:
+
+    - Transactions with max fee equal or higher than current block base fee
+    - Transactions with and without value
+    - Transactions with and without calldata
+    - Transactions with max fee per blob gas lower or higher than the priority fee
+    - Transactions where an externally owned account sends funds to the sender mid execution
+    """
+    assert len(txs) == 1
+    pre[destination_account] = Account(
+        balance=mid_tx_send_amount,
+        code=Op.SSTORE(0, Op.BALANCE(Op.ORIGIN))
+        + Op.CALL(Op.GAS, Op.ORIGIN, mid_tx_send_amount, 0, 0, 0, 0)
+        + Op.SSTORE(1, Op.BALANCE(Op.ORIGIN)),
+    )
+    post = {
+        destination_account: Account(
+            storage={
+                0: pre[TestAddress].balance - total_account_transactions_fee,
+                1: pre[TestAddress].balance - total_account_transactions_fee + mid_tx_send_amount,
+            }
+        )
+    }
+    state_test(
+        pre=pre,
+        post=post,
+        tx=txs[0],
+        env=state_env,
+    )
+
+
 @pytest.mark.parametrize(
     "blobs_per_tx",
     all_valid_blob_combinations(),