def test_is_valid_refund():
initiator = factories.ADDR
target = factories.HOP1
valid_sender = factories.HOP2
transfer = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=target,
expiration=50,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
refund_lower_expiration = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=target,
expiration=35,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
assert mediator.is_valid_refund(transfer, valid_sender,
refund_lower_expiration) is True
# target cannot refund
assert mediator.is_valid_refund(transfer, target,
refund_lower_expiration) is False
refund_same_expiration = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=factories.HOP1,
expiration=50,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
assert mediator.is_valid_refund(transfer, valid_sender,
refund_same_expiration) is False
def test_is_valid_refund():
initiator = factories.ADDR
target = factories.HOP1
valid_sender = factories.HOP2
transfer = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=target,
expiration=50,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
refund_lower_expiration = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=target,
expiration=35,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
assert mediator.is_valid_refund(transfer, valid_sender, refund_lower_expiration) is True
# target cannot refund
assert mediator.is_valid_refund(transfer, target, refund_lower_expiration) is False
refund_same_expiration = LockedTransferState(
identifier=20,
amount=30,
token=factories.UNIT_TOKEN_ADDRESS,
initiator=initiator,
target=factories.HOP1,
expiration=50,
hashlock=factories.UNIT_HASHLOCK,
secret=None,
)
assert mediator.is_valid_refund(transfer, valid_sender, refund_same_expiration) is False
def handle_transferrefundcancelroute(
payment_state: InitiatorPaymentState,
state_change: ReceiveTransferRefundCancelRoute,
channelidentifiers_to_channels: initiator.ChannelMap,
pseudo_random_generator: random.Random,
block_number: typing.BlockNumber,
) -> TransitionResult:
channel_identifier = payment_state.initiator.channel_identifier
channel_state = channelidentifiers_to_channels[channel_identifier]
refund_transfer = state_change.transfer
original_transfer = payment_state.initiator.transfer
maximum_expiration = original_transfer.lock.expiration - channel_state.reveal_timeout
if channel_state.close_transaction:
closed_block_number = channel_state.close_transaction.finished_block_number
else:
closed_block_number = None
# This is overcommiting, since the initiator knows the secret it doesn't
# need to wait for reveal_timeout blocks.
timeout_blocks = mediator.get_timeout_blocks(
channel_state.settle_timeout,
closed_block_number,
original_transfer.lock.expiration,
block_number,
)
lock_timeout = timeout_blocks - channel_state.reveal_timeout
maximum_expiration = lock_timeout + block_number
is_valid_lock = (
refund_transfer.lock.secrethash == original_transfer.lock.secrethash
and refund_transfer.lock.amount == original_transfer.lock.amount
and refund_transfer.lock.expiration <= maximum_expiration)
is_valid_refund = mediator.is_valid_refund(
original_transfer,
refund_transfer,
)
events = list()
if is_valid_lock and is_valid_refund:
is_valid, channel_events, _ = channel.handle_receive_refundtransfercancelroute(
channel_state,
refund_transfer,
)
events.extend(channel_events)
if is_valid:
old_description = payment_state.initiator.transfer_description
transfer_description = TransferDescriptionWithSecretState(
old_description.payment_identifier,
old_description.amount,
old_description.token_network_identifier,
old_description.initiator,
old_description.target,
state_change.secret,
)
payment_state.initiator.transfer_description = transfer_description
sub_iteration = handle_cancelroute(
payment_state,
state_change,
channelidentifiers_to_channels,
pseudo_random_generator,
block_number,
)
events.extend(sub_iteration.events)
if sub_iteration.new_state is None:
payment_state = None
iteration = TransitionResult(payment_state, events)
return iteration
def handle_transferrefund(payment_state, state_change,
channelidentifiers_to_channels, block_number):
channel_identifier = payment_state.initiator.channel_identifier
channel_state = channelidentifiers_to_channels[channel_identifier]
refund_transfer = state_change.transfer
original_transfer = payment_state.initiator.transfer
maximum_expiration = original_transfer.lock.expiration - channel_state.reveal_timeout
if channel_state.close_transaction:
closed_block_number = channel_state.close_transaction.finished_block_number
else:
closed_block_number = None
# This is overcommiting, since the initiator knows the secret it doesn't
# need to wait for reveal_timeout blocks.
timeout_blocks = mediator.get_timeout_blocks(
channel_state.settle_timeout,
closed_block_number,
original_transfer.lock.expiration,
block_number,
)
lock_timeout = timeout_blocks - channel_state.reveal_timeout
maximum_expiration = lock_timeout + block_number
is_valid_lock = (
refund_transfer.lock.secrethash == original_transfer.lock.secrethash
and refund_transfer.lock.amount == original_transfer.lock.amount
and refund_transfer.lock.expiration <= maximum_expiration)
is_valid_refund = mediator.is_valid_refund(
original_transfer,
refund_transfer,
)
events = list()
if is_valid_lock and is_valid_refund:
is_valid, _ = channel.handle_receive_refundtransfer(
channel_state,
refund_transfer,
)
if is_valid:
old_description = payment_state.initiator.transfer_description
transfer_description = TransferDescriptionWithSecretState(
old_description.identifier,
old_description.amount,
old_description.registry,
old_description.token,
old_description.initiator,
old_description.target,
state_change.secret,
)
payment_state.initiator.transfer_description = transfer_description
sub_iteration = handle_cancelroute(
payment_state,
state_change,
channelidentifiers_to_channels,
block_number,
)
events = sub_iteration.events
if sub_iteration.new_state is None:
payment_state = None
iteration = TransitionResult(payment_state, events)
return iteration
