evilissimo/design-by-contract
Analyze code to suggest and add Design by Contract specifications (preconditions, postconditions, invariants, semantic invariants) in any language. Trigger on: "Design by Contract", "DBC", "preconditions", "postconditions", "class invariants", "code contracts", "formal specifications", "document assumptions", "add contracts", "make this function safer", "define what this function guarantees", "add assertions to document behavior", Bertrand Meyer, Eiffel contracts, or when discussing invariants that should always hold. Do NOT skip for non-Eiffel code — DBC applies everywhere via assertions, type guards, properties.
92
90%
Does it follow best practices?
Impact
95%
1.05xAverage score across 5 eval scenarios
Passed
No known issues
task.mdevals/scenario-3/
Bank Account Contracts
Problem/Feature Description
A finance training app has a small account class used in examples and tests. New learners accidentally create negative balances and overdraft accounts, which then makes later examples confusing. Add contract-style documentation and checks so account objects remain valid after every operation.
Output Specification
Produce account_contract_analysis.md, account.py, and account_contract_tests.py.
Input Files
=============== FILE: account.py ===============
class BankAccount:
def __init__(self, account_id, opening_balance=0):
self.account_id = account_id
self.balance = opening_balance
self.closed = False
def deposit(self, amount):
self.balance += amount
def withdraw(self, amount):
self.balance -= amount
def close(self):
self.closed = True