Splint

Splint is a Rubocop and Kibit inspired Clojure linter focused on style and code shape. It aims to warn about many of the guidelines in the Clojure Style Guide.

Why?

Why another Clojure linter? We have clj-kondo, eastwood, and kibit, in addition to clojure-lsp's capabilities built on top of clj-kondo. I have contributed to most of these, and recently took over maintenance of kibit. However, most of them aren't built to be easily modifiable, and while kibit's rules are simple, the underlying engine (built on core.logic) is quite slow. This means that adding or updating the various linting rules can be quite frustrating and taxing.

Inspired by RuboCop, I decided to try something new: A "fast enough" linting engine based on linting code shape, built to be easily extended.

Non-goals

For speed and simplicity, Splint doesn't run any code, it only works on the provided code as text. As such, it doesn't understand macros or perform any macro-expansion (unlike Eastwood) so it can only lint a given macro call, not the resulting code.

clj-kondo performs lexical analysis and can output usage and binding information, such as unused or incorrectly defined vars. At this time, Splint makes no such efforts. It is only focused on code shape, not code intent or meaning.

Speed comparison

$ tokei
===============================================================================
 Language            Files        Lines         Code     Comments       Blanks
===============================================================================
 Clojure               169       113620       102756         4266         6598
 ClojureC                4         1012          850           36          126
 ClojureScript          48        12666        11649          142          875

$ time lein kibit
...
real    34m30.395s
user    35m4.952s
sys     0m2.995s

$ time splint .
...
Linting took 7168ms, 696 style warnings

real    0m9.220s
user    0m49.501s
sys     0m0.321s

License

Copyright © Noah Bogart

Distributed under the Mozilla Public License version 2.0.