Negative Testing

What is Negative Testing?

Negative testing deliberately does the wrong things—submits invalid data, skips required steps, triggers errors—to confirm the application responds gracefully with clear messages instead of crashing or corrupting data. It's the essential counterpart to happy-path testing, since real users and attackers alike will inevitably do the unexpected. Robust negative coverage validates input validation, error handling, and boundary behavior. Recording these unhappy paths and asserting on the resulting error states makes sure your app fails safely, every time it's supposed to.