scalafmt

User documentation

Head over to the user docs for instructions on how to install scalafmt.

Quick help

• sbt compile on a clean machine will fail to compile the scalafmt-intellij project.
  • if you plan to develop the intellij plugin, run downloadIdea first to fetch the IntelliJ SDK (~600mb).
  • or, run sbt test or sbt core/compile (specific project).
• Run all unit tests: sbt test
• Run only formatting tests: tests/testOnly *FormatTests.
• Write new formatting test: read this doc.
• Build docs: sbt readme/run will create the docs, which you can open with open readme/target/scalatex/index.html. Docs are built with Scalatex.
• Hack on IntelliJ plugin: see this doc.
• Hack on SBT plugin: run sbt scripted.
• Run jmh benchmarks: ./bin/run-benchmarks.sh.
• Run formatter on millions of lines of code: tests/test:runMain org.scalafmt.ScalafmtProps (slow, and requires a lot of memory/cpu)
• Debug performance: after each test run in FormatTests, a flamegraph report like this one is generated in target/index.html. I usually keep a browser tab open at localhost:3000/target/index.html along with this background process: browser-sync start --server --files "target/*.html". See Browsersync.
• intellij/compile:compileIncremental failed? Run downloadIdea to download custom IntelliJ plugin. The download may take a while.

Tutorial

If you'd like to find out how to work on scalafmt, see this tutorial.

Team

The current maintainers (people who can merge pull requests) are:

• Ólafur Páll Geirsson - @olafurpg
• Pedro J Rodriguez Tavarez - @pjrt
• Iurii Susuk - @ysusuk
• Paul Draper - @pauldraper

An up-to-date list of contributors is available here: https://github.com/scalameta/scalafmt/graphs/contributors

We strive to offer a welcoming environment to learn, teach and contribute.

Acknowledgements

JProfiler generously supports scalafmt with its full-featured Java Profiler.