ABA files generated are not balanced (no contra record)

[martinsd94]

ABA files generated are not balanced (no contra record)

Summary

When generating an ABA file with only credit transactions, the output does not include a contra (debit) entry and the trailer reflects a non-zero net total. Banks that require balanced files (e.g., CBA/CommBank) reject these files.

Impact

Payments cannot be uploaded/initiated for banks that require balanced files. Example error from CBA portal: “File is not balanced ... Cannot be automatically balanced.”

Expected behavior

• The library provides an option to auto-insert a contra (self-balancing) detail record to the nominated funding account, or

Balanced trailer example (net = 0, items incremented by 1 for the contra):

Type 7 trailer (balanced)
7999-999            000000000000114879820011487982                        000053

Actual behavior

The generator outputs only credit detail records (code 53) and a trailer with non-zero net and zero debit total:

Type 7 trailer (unbalanced)
7999-999            001148798200114879820000000000                        000052

Minimal reproduction

1. Create an ABA file consisting exclusively of multiple credit (53) transactions.
2. Generate the file
3. Upload to Bank (e.g: CBA/CommBiz) → upload fails with “ABA File is not balanced.”

[koresar]

Thank you @martinsd94

Could you please submit such PR? Make sure it's got a unit test for that. We will publish it as soon as you submit. You won't be waiting for days, I promise. :)