Property-based testing

Automated test case generation that probes edge cases by verifying universal code invariants rather than specific inputs.

Property-based testing (PBT) shifts the focus from manual example-based assertions to defining high-level specifications that must always hold true. Tools like Hypothesis for Python or QuickCheck for Haskell generate hundreds of randomized inputs (including null bytes, empty strings, and max integers) to find failing scenarios that developers often overlook. When a failure occurs, the engine performs shrinking: a process that automatically simplifies the complex input to the smallest possible counterexample. This approach provides 100% coverage of logic boundaries and uncovers deep architectural flaws with minimal boilerplate code.

https://hypothesis.works/