Introducing Kempt

kempt is a little hobby project I've put together to get away from Spotless/Gradle and simplify setting up commit hooks across my projects.

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TL;DR: kempt is a single-entry point CLI that delegates to language-specific formatters with easy installation, automatic binary management, git hook integration, license headers, whitespace handling, and simple configuration.

Spotless (and other formatter Gradle plugins) are frankly too heavy-weight because they run on Gradle. Most repos I work in that need to move away from Gradle-based formatting then eventually collect a familiar little pile of formatting scripts. kempt aims to turn that pile into one repo-local pipeline.

Right now it supports:

Kotlin via ktfmt
Java via google-java-format
Rust via cargo fmt
License header insertion
Trailing whitespace normalization. Repos configure it with a .kempt.toml, then use the same tool locally, in pre-commit, and in CI.

Quickstart

$ brew install ZacSweers/tap/kempt-fmt
$ kempt init           # inits a .kempt.toml based on detected langs
$ kempt install-hook   # optional git commit hook integration
$ kempt format|check   # runs the format or check

For CI, kempt check is the read-only mode. It exits non-zero when files need formatting and prints the command to fix them. For local commits, the hook formats staged files and re-stages only the files it changed, while refusing* unsafe partial-staging cases instead of silently pulling unrelated work into a commit.

Full usage/configuration/details are all in the repo README.md!

*it does support formatters that support partial formats! Namely GJF and (a future version of) ktfmt.