JarCastingneo-sbt-scalafmt
An sbt plugin for Scalafmt that
- formats .sbt and .scala files
- supports sbt 0.13 and 1.0.0-RC3
- supports Scalafmt 0.6 and 1.0
- runs in-process
- uses sbt's ivy2 for dependency resolution
Usage
In project/plugins.sbt,
// see the Maven badge at the top of this README for the latest version
addSbtPlugin("com.lucidchart" % "sbt-scalafmt" % "<version>")
// if you use coursier, you must use sbt-scalafmt-coursier
// addSbtPlugin("com.lucidchart" % "sbt-scalafmt-coursier" % "<version>")
then
> scalafmt # format compile sources
> test:scalafmt # format test sources
> sbt:scalafmt # format .sbt source
To ensure everything is formatted, and fail if it is not (e.g. as a CI step),
> scalafmt::test # check compile sources
> test:scalafmt::test # check test sources
> sbt:scalafmt::test # check .sbt sources
Scalafmt configuration
By default, .scalafmt.conf in the root project is used for Scalafmt configuration. If the file does not exist, the Scalafmt defaults are used. To choose another config file,
scalafmtConfig in ThisBuild := file("other.scalafmt.conf") // all projects
scalafmtConfig := file("other.scalafmt.conf") // current project
scalafmtConfig in Compile := file("other.scalafmt.conf") // current project, specific configuration
To change the Scalafmt version,
scalafmtVersion in ThisBuild := "1.0.0-RC2" // all projects
scalafmtVersion := "1.0.0-RC2" // current project
Task configuration
To run scalafmt automatically before compiling (or before loading, in the case of sbt).
scalafmtOnCompile in ThisBuild := true // all projects
scalafmtOnCompile := true // current project
scalafmtOnCompile in Compile := true // current project, specific configuration
To run scalafmt::test automatically before compiling (or before loading, in the case of sbt).
scalafmtTestOnCompile in ThisBuild := true // all projects
scalafmtTestOnCompile := true // current project
scalafmtTestOnCompile in Compile := true // current project, specific configuration
By default, scalafmt::test fails if sources are unformatted. If you'd prefer warnings instead:
scalafmtFailTest in ThisBuild := false // all projects
scalafmtFailTest := false // current project
scalafmtFailTest in Compile := false // current project, specific configuration
At the time of writing, Scalafmt fails on some valid inputs. By default, errors in Scalafmt itself do not fail the scalafmt task. To fail instead,
ignoreErrors in (ThisBuild, scalafmt) := false // all projects
ignoreErrors in scalafmt := false // current project
ignoreErrors in (Compile, scalafmt) := false // current project, specific configuration
By default, scalafmt just lists the files that have differences. You can configure it to show the actual diff like this:
scalafmtShowDiff in (ThisBuild, scalafmt) := true // all projects
scalafmtShowDiff in scalafmt := true // current project
scalafmtShowDiff in (Compile, scalafmt) := true // current project, specific configuration
Additional configuration
The scalafmt task is defined by default for the compile and test configurations. To define it for additional configurations, e.g. Integration,
inConfig(Integration)(scalafmtSettings)
To disable this plugin for a project
disablePlugins(ScalafmtCorePlugin)
Formatting build files
If you wish to format project/*.scala files, configure the meta-build by adding sbt-scalafmt to project/project/plugins.sbt, and configuring it in project/plugins.sbt. See sbt documentation on meta-builds.
Implementation details
Scalafmt artifacts are downloaded with a scalafmt Ivy configuration added to each project. Scalafmt classes are loaded in a separate classloader, allowing them work regardless of the Scala version of sbt.
ScalafmtCorePluginadds the Ivy configuration and scalafmt dependency.ScalafmtCoursierPluginreplaces the sbt ivy configuration with coursier.ScalafmtSbtPlugincreate scalafmt tasks for .sbt sources.ScalafmtPlugincreates the scalafmt task for compile and test configurations.
Scalafmt requires Java 8+.
