//contract.requires public void Withdraw(Account account, decimal amount) { Contract.Requires(account != null, "account cannot be null"); Contract.Requires(amount > 0, "amount must be greater than zero"); ... } //contract.ensures public double CalculateDiscount(int originalAmount, string discountCode) { Contract.Ensures(Contract.Result<double>() >= 0); return -32; }
Reference
http://visualstudiomagazine.com/articles/2010/06/23/code-contracts.aspx
http://msdn.microsoft.com/en-us/library/dd264808(v=vs.110).aspx