I think they have custom rules in the works, using `trustfall` query engine and yaml definitions
https://github.com/oxc-project/oxc/tree/main/crates/oxc_quer...
https://github.com/oxc-project/oxc/tree/main/crates/oxc_quer...
I'm the Trustfall maintainer, happy to answer questions about the query engine or how oxlint or cargo-semver-checks use it.
I also recently gave a talk at P99 CONF on how cargo-semver-checks used Trustfall's optimizations API to get a 2000x speedup: https://www.youtube.com/watch?v=Fqo8r4bInsk