def test_transaction_update():
sender_wallet = Wallet()
first_recipient = 'first_recipient'
first_amount = 50
transaction = Transaction(sender_wallet, first_recipient, first_amount)
next_recipient = 'next_recipient'
next_amount = 75
transaction.update(sender_wallet, next_recipient, next_amount)
assert transaction.output[next_recipient] == next_amount
assert transaction.output[sender_wallet.address] ==\
sender_wallet.balance - first_amount - next_amount
assert Wallet.verify(transaction.input['public_key'], transaction.output,
transaction.input['signature'])
to_first_again_amount = 25
transaction.update(sender_wallet, first_recipient, to_first_again_amount)
assert transaction.output[first_recipient] ==\
first_amount + to_first_again_amount
assert transaction.output[sender_wallet.address] ==\
sender_wallet.balance - first_amount - next_amount - to_first_again_amount
assert Wallet.verify(transaction.input['public_key'], transaction.output,
transaction.input['signature'])
def test_transaction_update_exceeds_balance():
sender_wallet = Wallet()
transaction = Transaction(sender_wallet, 'recipient', 50)
with pytest.raises(Exception, match='Amount exceeds balance'):
transaction.update(sender_wallet, 'new_recipient', 9001)
