# Kit 2: The Edge-Test Checklist

**Use when:** the rebuilt sheet is done and a copy is about to become the real file.

```
Edge case                | How to set it up                        | Expected outcome                                        | Actual (fill in)
Zero                     | Put 0 where a rate or revenue belongs.  | A 0 result or an explicit flag, never a silent blank. | [...]
Negative                 | Enter a credit or a refund.              | Signs stay correct. No absolute-value surprise.            | [...]
Blank                    | Leave a required cell empty.             | A visible error or a deliberate default, never a silent wrong number. | [...]
Huge                     | Double the biggest value your data has ever seen. | Totals still add up. Nothing overflows into the next column. | [...]
Duplicate                | Paste the same row twice, same ID.       | The total doubles on purpose, or the file warns you. No quiet collapse. | [...]
Text in a number column  | Type N/A into a numeric field.           | A loud error or a flag. Not a quiet zero.                  | [...]
```

Run the set on a copy, never the real file. Anything unexpected in the last column is a bug found while it was cheap.

A checkable version of this page lives in the kit's `checklists/` folder as `edge-test-checklist.md`.