def test_valid_transaction_with_invalid_outputs():
sender_wallet = Wallet()
transaction = Transaction(sender_wallet, 'reciepient', 50)
transaction.output[sender_wallet.address] = 1998
with pytest.raises(Exception, match='Invalid transaction output values'):
Transaction.transaction_is_valid(transaction)
def is_valid_transaction_chain(chain):
"""
Enforce the rules of a chain composed of blocks of transactions
- each transaction must only appear once in the chain
- There can be only one mining reward per block
- Each transaction must be valid
"""
transaction_ids = set()
for i in range(len(chain)):
block = chain[i]
has_mining_reward = False
for transaction_json in block.data:
transaction = Transaction.from_json(transaction_json)
if transaction.id in transaction_ids:
raise Exception(f'Transaction: {transaction.id} is not unique')
transaction_ids.add(transaction.id)
if transaction.input == MINING_REWARD_INPUT:
if has_mining_reward:
raise Exception(f'There can be only one mining reward per block check this block: {block.hash}')
has_mining_reward = True
else:
historic_blockchain = Blockchain()
historic_blockchain.chain = chain[0:i]
historic_balance = Wallet.calculate_balance(historic_blockchain, transaction.input['address'])
if historic_balance != transaction.input['amount']:
raise Exception(f'Transaction {transaction.id} has '\
'invalid input amount')
Transaction.transaction_is_valid(transaction)
def test_valid_reward_transaction():
reward_transaction = Transaction.reward_transaction(Wallet())
Transaction.transaction_is_valid(reward_transaction)
def test_valid_transaction_with_invalid_signature():
transaction = Transaction(Wallet(), 'reciepient', 50)
transaction.input['signature'] = Wallet().sign(transaction.output)
with pytest.raises(Exception, match='Invalid signature'):
Transaction.transaction_is_valid(transaction)
def test_valid_transaction():
Transaction.transaction_is_valid(Transaction(Wallet(), 'reciepient', 50))
def test_invalid_reward_transaction_invalid_amount():
miner_wallet = Wallet()
reward_transaction = Transaction.reward_transaction(miner_wallet)
reward_transaction.output[miner_wallet.address] = 1998
with pytest.raises(Exception, match='Invalid Mining Reward'):
Transaction.transaction_is_valid(reward_transaction)
def test_invalid_reward_transaction_extra_reciepient():
reward_transaction = Transaction.reward_transaction(Wallet())
reward_transaction.output['extra_reciepient'] = 60
with pytest.raises(Exception, match='Invalid Mining Reward'):
Transaction.transaction_is_valid(reward_transaction)