Test Excess Blob Gas Fork Transition

Documentation for tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py.

Generate fixtures for these test cases for Cancun with:

Cancun only:

fill -v tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py --fork=Cancun --evm-bin=/path/to/evm-tool-dev-version

For all forks up to and including Cancun:

fill -v tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py --until=Cancun --evm-bin=/path/to/evm-tool-dev-version

Tests excessBlobGas and blobGasUsed block fields for EIP-4844: Shard Blob Transactions at fork transition.

Test excessBlobGas and blobGasUsed block fields for EIP-4844: Shard Blob Transactions at fork transition.

test_invalid_pre_fork_block_with_blob_fields(blockchain_test, env, pre, pre_fork_blocks, excess_blob_gas_present, blob_gas_used_present)

Test block rejection when excessBlobGas and/or blobGasUsed fields are present on a pre-fork block.

Source code in tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py

@pytest.mark.parametrize(
    "excess_blob_gas_present,blob_gas_used_present",
    [
        (True, False),
        (False, True),
        (True, True),
    ],
)
def test_invalid_pre_fork_block_with_blob_fields(
    blockchain_test: BlockchainTestFiller,
    env: Environment,
    pre: Mapping[str, Account],
    pre_fork_blocks: List[Block],
    excess_blob_gas_present: bool,
    blob_gas_used_present: bool,
):
    """
    Test block rejection when `excessBlobGas` and/or `blobGasUsed` fields are present on a pre-fork
    block.
    """
    header_modifier = Header()
    if excess_blob_gas_present:
        header_modifier.excess_blob_gas = 0
    if blob_gas_used_present:
        header_modifier.blob_gas_used = 0
    blockchain_test(
        pre=pre,
        post={},
        blocks=pre_fork_blocks[:-1]
        + [
            Block(
                timestamp=(FORK_TIMESTAMP - 1),
                rlp_modifier=header_modifier,
                exception="invalid field",
            )
        ],
        genesis_environment=env,
        tag="invalid_pre_fork_excess_blob_gas",
    )

test_invalid_post_fork_block_without_blob_fields(blockchain_test, env, pre, pre_fork_blocks, excess_blob_gas_missing, blob_gas_used_missing)

Test block rejection when excessBlobGas and/or blobGasUsed fields are missing on a post-fork block.

Source code in tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py

@pytest.mark.parametrize(
    "excess_blob_gas_missing,blob_gas_used_missing",
    [
        (True, False),
        (False, True),
        (True, True),
    ],
)
def test_invalid_post_fork_block_without_blob_fields(
    blockchain_test: BlockchainTestFiller,
    env: Environment,
    pre: Mapping[str, Account],
    pre_fork_blocks: List[Block],
    excess_blob_gas_missing: bool,
    blob_gas_used_missing: bool,
):
    """
    Test block rejection when `excessBlobGas` and/or `blobGasUsed` fields are missing on a
    post-fork block.
    """
    header_modifier = Header()
    if excess_blob_gas_missing:
        header_modifier.excess_blob_gas = Header.REMOVE_FIELD
    if blob_gas_used_missing:
        header_modifier.blob_gas_used = Header.REMOVE_FIELD
    blockchain_test(
        pre=pre,
        post={},
        blocks=pre_fork_blocks
        + [
            Block(
                timestamp=FORK_TIMESTAMP,
                rlp_modifier=header_modifier,
                exception="missing field",
            )
        ],
        genesis_environment=env,
        tag="excess_blob_gas_missing_post_fork",
    )

test_fork_transition_excess_blob_gas(blockchain_test, env, pre, pre_fork_blocks, post_fork_blocks, post)

Test excessBlobGas calculation in the header when the fork is activated.

Also produce enough blocks to test the blob gas price increase when the block is full with SpecHelpers.max_blobs_per_block() blobs.

Source code in tests/cancun/eip4844_blobs/test_excess_blob_gas_fork_transition.py

@pytest.mark.parametrize(
    "post_fork_block_count,blob_count_per_block",
    [
        (
            SpecHelpers.get_min_excess_blobs_for_blob_gas_price(2)
            // (SpecHelpers.max_blobs_per_block() - SpecHelpers.target_blobs_per_block())
            + 2,
            SpecHelpers.max_blobs_per_block(),
        ),
        (10, 0),
        (10, SpecHelpers.target_blobs_per_block()),
    ],
    ids=["max_blobs", "no_blobs", "target_blobs"],
)
def test_fork_transition_excess_blob_gas(
    blockchain_test: BlockchainTestFiller,
    env: Environment,
    pre: Mapping[str, Account],
    pre_fork_blocks: List[Block],
    post_fork_blocks: List[Block],
    post: Mapping[str, Account],
):
    """
    Test `excessBlobGas` calculation in the header when the fork is activated.

    Also produce enough blocks to test the blob gas price increase when the block is full with
    `SpecHelpers.max_blobs_per_block()` blobs.
    """
    blockchain_test(
        pre=pre,
        post=post,
        blocks=pre_fork_blocks + post_fork_blocks,
        genesis_environment=env,
        tag="correct_initial_blob_gas_calc",
    )