Pragmatic verification.
WHEN THIS APPLIES
Small scripts where formal tests are disproportionate.
WHAT TO DO INSTEAD
Build a mode that runs the script against known input and checks the output Keep sample input files with known correct results Verify totals against a known figure
WHAT TO ALWAYS CHECK
Record counts Totals That output was produced at all
WHY
Those catch most failures without any framework.
WHAT TO BUILD IN
Validation that fails loudly when something is wrong.
WHAT TO KEEP
A small sample dataset covering awkward cases.
WHY
So you can verify quickly after any change.
WHAT AWKWARD CASES INCLUDE
Empty input Missing fields Unusual characters Values at boundaries Duplicates
WHAT TO DO BEFORE ANY CHANGE
Run against the sample and record the result.
Then compare after.
WHAT THAT GIVES YOU
Most of the benefit of tests, at a fraction of the effort.
