Luke Boswell (Aug 08 2026 at 01:05): Luke Boswell (Aug 08 2026 at 01:05):Ever wanted to fuzz pure Roc code ... well now you can use roc-fuzz!!!
https://github.com/lukewilliamboswell/roc-fuzz
The platform wraps libFuzzer and provides everything in a easy to use setup so you can build a normal roc app and you get a self contained fuzz target with running, minimizing, and corpus compaction features.
roc build --fuzz my_target_app.roc
./my_target_app --help
./my_target_app run
Currently supports Linux x64 musl -- but aarch64 Macos and x64 Windows are probably coming soon. I haven't tried building all the libraries and testing on those targets yet.
Luke Boswell (Aug 08 2026 at 01:07):This work originated from @Brendan Hansknecht who the heavy lifting regarding setting up libFuzzer and ensuring Roc is capable of supporting this use case. I forked some of his earlier work in this space and was able to package it up in our modern syntax and make a release.
Luke Boswell (Aug 08 2026 at 01:25):Also if you are not familiar with fuzz testing in general, I added both a beginner and advanced guides and documentation which walk you through how to do it well.
Luke Boswell (Aug 08 2026 at 01:49):Also if you are working on a Roc builtin or PRs for Roc this can be very helpful to surface bugs. @Eric Rogstad @JRI98 @Dzmitry Misiuk
I found one yesterday in the builtins just while testing this https://github.com/roc-lang/roc/issues/10660
Austin Clements (Aug 08 2026 at 02:32):Awesome I’ve been wanting this!!
Last updated: Aug 12 2026 at 12:35 UTC