WHY PROPERTY TESTING FINDS BUGS UNIT TESTING DOES NOT

Summary from the TLDR Web Dev newsletter

Property-Based Testing (PBT) is great at uncovering bugs that unit tests miss due to the combinatorial explosion of edge cases in complex systems. While unit tests focus on specific inputs, PBT uses randomized inputs to test general properties, revealing unexpected interactions between multiple variables. The advantage of PBT increases with the complexity of the input space, such as multiple integer inputs or nested data structures, where manual identification of edge cases becomes too hard.