A linter for OCaml+dune projects

A linter is a tool that discovers bugs and obscurities in the code. The name was invented in 1978 paper of S. C. Johnson: Lint, a C Program Checker.

This is a list of currently supported analyses.

From techinical point of view, most of the lints study Typedtree, so the input for linter should be a fully compiled dune project. There is a support of linters that study untyped tree, but I don't expect them to be widely used. These two abstract trees don't allow to find all possible code quirks. Currently, we delegate job of detecting something like f(1)(2)(3) to ocamlformat.

This linter is inspired by:

• How possible is a clippy-like linter for OCaml?
• My experience in teaching OCaml at my local university.

But I'm aware that there are other linters like Camelot for OCaml and Clippy Rust.

Usage

Examples of 'zanuda' usage could be found in the 'tests' directory. But in short:

• Compile your dune project and run this linter via

  dune build @check @runtest -j3
  zanuda -dir .

  It will report found issues using OCaml's alerts

• You could read the documentation about supported lints via zanuda -dump. CI runs regularly uploads information about available lints to GitHub Pages.

• You could run linter and dump the results in short JSON form: zanuda -dir . -ordjsonl /tmp/1.rdjsonl. They could be processed later, for example as review comment via GitHub API. (This reporting is not implemented yet.)

Developping

To get dependecies you could use standard dune/opam machinery:

opam pin add ./ -n
opam install . --deps-only --with-test --with-doc

Running a single test:

dune b @tests/typed/License

Running all tests:

dune test

See also

• Rescript Reanalyze
• Sem grep
• Ocp-lint paper
• Lexifi's dead dead_code_analyzer
• Camelot
• ometrics