How Sellka was tested

A test program ran a busy shop on a real phone: cash and credit sales, part payments, returns, deliveries and payments to suppliers, saved exactly as Sellka saves them when a shop owner taps the buttons. It traded 365 days and wrote 39,174 records.

It kept its own separate books as it went, in exact figures. At the end it compared every Sellka figure with its own: sales, the cost of the goods sold, what was kept, stock, and what every customer owed and what was owed to every supplier. None was different.

Phones close apps without warning when memory runs low, and a record half saved is worse than one never saved. A second test closed Sellka in the middle of saving, 25 times on each of two phones, one of them on Android 10. Then it checked every record. Each one was either whole or not there at all. None was half saved.

The tests were not run to be passed. They found faults, in how payments on two credit sales made the same day were matched and in how a returned sale's cost was counted, and those were fixed before release and tested again. That is what the tests are for.

The page inside the app, under How Sellka was tested, shows each phone the tests ran on, the dates the records cover, how many of each kind of record there were, and every kind of figure that was compared: each day, each week, each month, each product sold, stock on the shelf, what each customer owes and what the shop owes each supplier. Nothing on that page is typed. Each figure is read from the result a test wrote.

You need a pen and paper.

1. Save a copy of your records first: open the menu, tap Your records, then Save a copy.
2. Record a few practice sales: a cash sale, a credit sale, a part payment, then undo one sale.
3. Write the same sales on paper and add them up.
4. Compare your paper with Today on Home, with Money, and with the Daily report in Reports. They should match.
5. Remove the practice records: open the menu, tap Your records, then Remove records, and choose to remove what you recorded, which keeps your products and prices.