junit-quickcheck VS jazzer

For anyone interested, there's also https://github.com/pholser/junit-quickcheck . Haven't used it myself but looks like an interesting library to explore. It's based on QuickCheck as well AFAIK.

Thank you for the insightful reply. I did struggle to convert the original algorithm I wrote (with while loops / continue / break) to a more functional style using unfold, and also faced an issue with the type signatures when I tried to break down the contents of Stream.unfoldRight to multiple functions, which is reflected to the messy state you mentioned. Regarding property based testing, I used junit-quickcheck and the "symmetry" property check was one I meant to write but wasn't quite sure how to create a generator for it. I created an issue to track my attempt to incorporate your suggestions in case you are interested in following this. Thanks again!

A quick Google search shows that java has a library for this (here) but I've never used it in java so can't attest to it.

QuickcCheck-type tools (generators for tests that know about the edge cases of a domain - e. g. for the domain of numbers considering things like 0, the infinities, various almost-and-just-over powers of two, NaN and mantissas for floats, etc.):

* QuickCheck: https://hackage.haskell.org/package/QuickCheck

* Hypothesis: https://hypothesis.readthedocs.io/en/latest/

* JUnit QuickCheck: https://github.com/pholser/junit-quickcheck

Fuzz testing tools (tools which mutate the inputs to a program in order to find interesting / failing states in that program). Generally paired with code coverage:

* American Fuzzy Lop (AFL): https://github.com/google/AFL

* JQF: https://github.com/rohanpadhye/JQF

Mutation / Fault based test tools (review your existing unit coverage and try to introduce changes to your _production_ code that none of your tests catch)

* PITest: https://pitest.org/

If you want an easy way to have better mutation coverage, check out property based testing. Eg junit-quickcheck for Java.

https://github.com/pholser/junit-quickcheck

Check out Jazzer, the code intelligence blog, and search for custom sanitizers for Java etc. https://github.com/CodeIntelligenceTesting/jazzer

Input Generation: The tester uses a fuzzing tool such as CI Fuzz or Jazzer to generate random or unexpected inputs to the software application.

Fuzzing is a testing technique where random values are generated as inputs to find unexpected behavior such as crashes and security issues. Previously we looked at the new Golang release 1.18 which includes native fuzzing and our Core Technology blog series contained a post that compares symbolic execution to different other testing techniques, including fuzzing. Today, we will dive into the Java world and check out the most popular Java fuzzing solution: Jazzer.

Coverage-guided fuzzer for Java

$ git clone https://github.com/CodeIntelligenceTesting/jazzer $ cd jazzer $ ./bazelisk-linux-amd64 run //:jazzer Starting local Bazel server and connecting to it... INFO: Analyzed target //:jazzer (79 packages loaded, 1410 targets configured). INFO: Found 1 target... Target //:jazzer up-to-date: bazel-bin/jazzer INFO: Elapsed time: 43.920s, Critical Path: 7.21s INFO: 83 processes: 4 internal, 79 linux-sandbox. INFO: Build completed successfully, 83 total actions INFO: Build completed successfully, 83 total actions driver/jazzer_driver: error while loading shared libraries: libjvm.so: cannot open shared object file: No such file or directory

One of the authors of Jazzer here. Feel free to ask any questions regarding Jazzer (https://github.com/CodeIntelligenceTesting/jazzer) or how to integrate Java/JVM projects into OSS-Fuzz.