How to fuzz HyperLogLog-rs

Fuzzing is an essential part of any library's testing suite. It helps to identify potential bugs and vulnerabilities that traditional testing may not catch. HyperLogLog-rs provides a simple and easy way to run fuzz tests using cargo-fuzz.

To fuzz this library, simply install cargo-fuzz as such:

cargo install cargo-fuzz

and then you can start one how the fuzzer harness as such:

cargo fuzz run registers_symmetry

Happy fuzzing!

Available fuzz targets

At this time, I have prepared and executed four different fuzzing targets. Of course, though to the inherent probabilistic nature of the HLL counters there is some additional difficulty in comparing it against the power bounds of the fuzzing harness. However, I have found that the fuzzing harnesses are able to find some interesting bugs in the library, and I have been able to fix them as a result. Here is the list of fuzzing targets that I have prepared:

registers_symmetry

Here we test whether two registered manipulated side by side using what are in theory identical methods actually produce the same results and that all relative methods maintain coherence.

cargo fuzz run registers_symmetry

cardinality

Here we test whether the cardinality estimation is correct for random inputs.

cargo fuzz run cardinality

intersection_cardinality

Here we test whether the cardinality estimation of HLL intersections is correct for random inputs.

cargo fuzz run intersection_cardinality

sketching

Here we test whether the sketching of HLL counters is correct for random inputs, and that the various methods available are coherent between one another.

cargo fuzz run sketching