def test_is_valid_transaction_chain_bad_historic_balance(blockchain_three_blocks):
wallet = Wallet()
bad_transaction = Transaction(wallet, 'recipient', 1)
bad_transaction.output[wallet.address] = 9000
bad_transaction.input['amount'] = 9001
bad_transaction.input['signature'] = wallet.sign(bad_transaction.output)
blockchain_three_blocks.add_block([bad_transaction.to_json()])
with pytest.raises(Exception, match='has an invalid input amount'):
Blockchain.is_valid_transaction_chain(blockchain_three_blocks.chain)
def test_verify_valid_signature():
data = {'foo': 'test_data'}
wallet = Wallet()
signature = wallet.sign(data)
assert Wallet.verify(wallet.public_key, data, signature)