def test_for_bad_historic_balance_in_is_valid_transaction_chain(three_block_blockchain): wallet = Wallet() bad_transaction = SystemTransactions(wallet, 'recipient', 1) bad_transaction.transaction_output[wallet.address] = 9000 bad_transaction.transaction_input['amount'] = 9001 bad_transaction.transaction_input['signature'] = wallet.signature_generation(bad_transaction.transaction_output) three_block_blockchain.add_block([bad_transaction.convert_transaction_data_to_json()]) with pytest.raises(Exception, match='has an invalid input amount'): Blockchain.transaction_chain_is_valid(three_block_blockchain.chain)