def test_valid_transaction_with_invalid_signature():
trans = Transaction(Wallet(), 'recipient', 50)
# Try to update the signature with a new signature that uses a new signed
# version of the valid transaction output data.
trans.input['signature'] = Wallet().sign(trans.output)
with pytest.raises(Exception, match='Invalid Signature'):
Transaction.is_valid(trans)
def is_valid_trans_chain(chain):
'''
Enforce the rules of a chain composed of blocks of transaction.
- Each transaction must only appear ONCE in the chain.
- There can only be ONE mining reward per block.
- Each transaction MUST be valid.
'''
trans_ids = set()
for i in range(len(chain)):
block = chain[i]
has_mining_reward = False
for trans_json in block.data:
trans = Transaction.from_json(trans_json)
if trans.input == MINING_REWARD_INPUT:
if has_mining_reward:
raise Exception('There can only be one mining reward '
'per block. Check block with hash: '
f'{block.hash}')
has_mining_reward = True
else:
if trans.id in trans_ids:
raise Exception(
f'Transaction {trans.id} is not unique.')
trans_ids.add(trans.id)
historic_blockchain = Blockchain()
historic_blockchain.chain = chain[0:i]
historic_balance = Wallet.calculate_balance(
historic_blockchain, trans.input['address'])
if historic_balance != trans.input['amount']:
raise Exception(
f'Transaction {trans.id} has an invalid input amount.'
)
Transaction.is_valid(trans)
def test_valid_transaction_with_invalid_outputs():
sender_wallet = Wallet()
trans = Transaction(sender_wallet, 'recipient', 50)
trans.output[sender_wallet.address] = 9001
with pytest.raises(Exception, match='Invalid transaction output values'):
Transaction.is_valid(trans)
def test_valid_transaction():
Transaction.is_valid(Transaction(Wallet(), 'recipient', 50))
def test_invalid_reward_transaction_invalid_amount():
miner_wallet = Wallet()
reward_trans = Transaction.reward_transaction(miner_wallet)
reward_trans.output[miner_wallet.address] = 9001
with pytest.raises(Exception, match='Invalid mining reward'):
Transaction.is_valid(reward_trans)
def test_invalid_reward_transaction_extra_recipient():
reward_trans = Transaction.reward_transaction(Wallet())
reward_trans.output['extra_recipient'] = 60
with pytest.raises(Exception, match='Invalid mining reward'):
Transaction.is_valid(reward_trans)
def test_valid_reward_transaction():
reward_trans = Transaction.reward_transaction(Wallet())
Transaction.is_valid(reward_trans)
