Comparative language fuzz testing: programming languages vs. fat fingers.

We explore how programs written in ten popular programming languages are affected by small changes of their source code. This allows us to analyze the extend to which these languages allow the detection of simple errors at compile or at run time. Our study is based on a diverse corpus of programs written in several programming languages systematically perturbed using a mutation-based fuzz generator. The results we obtained prove that languages with weak type systems are significantly likelier than languages that enforce strong typing to let fuzzed programs compile and run, and, in the end, produce erroneous results. More importantly, our study also demonstrates the potential of comparative language fuzz testing for evaluating programming language designs.