def test_transaction_update_successful():
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
# Verifies making an update on a transaction correctly reduces the output inside the transaction class.
assert Wallet.verify(transaction.input['public_key'], transaction.output,
transaction.input['signature'])
# Update going to a recipient that already existed showing that they made two transactions.
to_first_again_amount = 50
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', 9000)