Checks how your server answers invalid callbacks. Every request is form-encoded and signed the way Click signs it.
1. Invalid Signature (Expects -1)
2. Missing Signature (Expects -1)
3. Wrong Service ID (Expects -1)
4. Unknown Account (Expects -5)
5. Invalid Amount (Expects -2)
6. Unknown Action (Expects -3)
Runs the Click prepare/complete flow: Prepare, repeated Prepare, Complete, repeated Complete and a second payment attempt on the same account.
In one-time mode an account can be paid once, so use an unpaid account for each run.
Prepares a transaction, completes it with a negative error code and then re-uses the same click_trans_id, which must be refused with -9.
Run this on an unpaid account: in one-time mode a paid account answers 0 before a new transaction is created.