Thirdparty Plugins

The Plugins in this section are developed/maintained outside the mill git tree. This list is most likely not complete. If you wrote a Mill plugin or find that one is missing in this list, please open a pull request and add that plugin with a short description (in alphabetical order).

For details about including plugins in your build.sc read Using Mill Plugins.

Besides the documentation provided here, we urge you to consult the respective linked plugin documentation pages. The usage examples given here are most probably incomplete and sometimes outdated!

Additional to this list, you can also search the mill-plugin topic on GitHub for more plugins.

Antlr

ANTLR parser generator support for mill.

Quickstart

import $ivy.`net.mlbox::mill-antlr:0.1.0`
import net.mlbox.millantlr.AntlrModule

object foo extends ScalaModule with AntlrModule {
  override def antlrGrammarSources = T.sources {
    Seq(os.pwd/"someGrammar.g4").map(PathRef(_))
  }
}

AspectJ

AspectJ compiler support for mill.

Quickstart

import mill._
import mill.scalalib._
import mill.define._

// Load the plugin from Maven Central via ivy/coursier
import $ivy.`de.tototec::de.tobiasroeser.mill.aspectj_mill0.9:0.3.1-12-89db01
import de.tobiasroeser.mill.aspectj._

object main extends AspectjModule {

  // Select the AspectJ version
  def aspectjVersion = "1.9.5"

  // Set AspectJ options, e.g. the language level and annotation processor
  // Run `mill main.ajcHelp` to get a list of supported options
  def ajcOptions = Seq("-8", "-proc:none")

}

For documentation, please refer to the project home page.

Bash Completion

Limited bash completion support.

CI Release

mill-ci-release is a wrapper around the existing publish functionality of Mill with the aim to making releasing your project in GitHub Actions to Maven easier by automating common setup such as setting up gpg in CI, setting up versioning, and ensuring merges to into your main branch get published as a SNAPSHOT. If you’re coming from sbt, then you’re likely familiar with sbt-ci-release which this plugin imitates.

Quickstart

To get started, you’ll want to use CiReleaseModule as a drop in replacement where you’d normally use the Mill PublishModule and then ensure you implement everything that PublishModule requires.

Secondly, you’ll need to ensure you have a few environment variables correctly set in your GitHub repo. You can see detailed instuctions on which are necessary here.

Then in CI to publish you’ll simply issue a single command:

- run: mill -i io.kipp.mill.ci.release.ReleaseModule/publishAll

This will automatically grab all the artifacts that you’ve defined to publish in your build and publish them. Your version will automatically be managed by mill-vcs-version and if your version ends in -SNAPSHOT you’re project will be published to Sonatype Snapshots or to the normal releases if it’s a new tag.

DGraph

Show transitive dependencies of your build in your browser.

Quickstart

import $ivy.`com.github.ajrnz::mill-dgraph:0.2.0`
sh> mill plugin.dgraph.browseDeps(proj)()

Docusaurus 2

Simple Docusaurus runner for Mill

The plugin provides a mill module that allows to build the project web site using Docusaurus 2 as a static content generator.

Ensime

Create an .ensime file for your build.

Quickstart

import mill._
interp.repositories() =
  interp.repositories() ++ Seq(coursier.MavenRepository("https://jitpack.io"))

@

import $ivy.`com.github.yyadavalli::mill-ensime:0.0.2`

You can then run the following to generate the .ensime file

mill fun.valycorp.mill.GenEnsime/ensimeConfig

Optionally, you can specify the ensime server version using the –server flag like

mill fun.valycorp.mill.GenEnsime/ensimeConfig --server "3.0.0-SNAPSHOT"

Explicit Deps

A plugin that checks that ivyDeps and ivyCompileDeps accurately reflect the direct dependencies of your source code.

Quickstart

build.sc
import $ivy.`io.github.kierendavies::mill-explicit-deps::0.1.0`
import io.github.kierendavies.mill.explicitdeps.ExplicitDepsModule

object foo extends ScalaModule with ExplicitDepsModule {
    // ...
}
> mill foo.checkExplicitDeps
[37/37] main.checkExplicitDeps
Found undeclared dependencies: (add these to ivyDeps)
    ivy"org.typelevel::cats-kernel:2.7.0",

Found unimported dependencies: (remove these from ivyDeps)
    ivy"org.typelevel::cats-effect:3.3.6",

1 targets failed
main.checkExplicitDeps Found 1 undeclared dependencies, 1 unimported dependencies

Fish Completion

Limited fish completion support.

Giter8

A plugin to test the generation of your Giter8 template and expected working targets for your template after generation.

Quickstart

build.sc
import $ivy.`io.chris-kipp::mill-giter8::0.2.0`

import io.kipp.mill.giter8.G8Module

object g8 extends G8Module {
  override def validationTargets =
    Seq("example.compile", "example.fix", "example.reformat")
}

The most common target you’d then use is mill g8.validate.

Git

A git version plugin for mill.

build.sc:

import $ivy.`com.goyeau::mill-git:<latest version>`
import com.goyeau.mill.git.GitVersionedPublishModule
import mill.scalalib.JavaModule
import mill.scalalib.publish.{Developer, License, PomSettings, VersionControl}

object `jvm-project` extends JavaModule with GitVersionedPublishModule {
  override def pomSettings = PomSettings(
    description = "JVM Project",
    organization = "com.goyeau",
    url = "https://github.com/joan38/mill-git",
    licenses = Seq(License.MIT),
    versionControl = VersionControl.github("joan38", "mill-git"),
    developers = Seq(Developer("joan38", "Joan Goyeau", "https://github.com/joan38"))
  )
}
> mill show jvm-project.publishVersion
[1/1] show
[2/2] com.goyeau.mill.git.GitVersionModule.version
"0.0.0-470-6d0b3d9"

GitHub Dependency Graph Submission

A plugin to submit your mill dependency graph to GiHub through their Dependency Submission API.

Quickstart

The easiest way to use this plugin is with the mill-dependency-submission action. You can add it as a workflow:

name: github-dependency-graph

on:
  push:
    branches:
      - main

jobs:
  submit-dependency-graph:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - uses: coursier/cache-action@v6
    - uses: actions/setup-java@v3
      with:
        distribution: 'temurin'
        java-version: '17'
    - uses: ckipp01/mill-dependency-submission@v1

Integration Testing Mill Plugins

Integration testing for mill plugins.

Quickstart

We assume, you have a mill plugin named mill-demo

// build.sc
import mill._, mill.scalalib._
object demo extends ScalaModule with PublishModule {
  // ...
}

Add a new test sub-project, e.g. itest.

// build.sc
import $ivy.`de.tototec::de.tobiasroeser.mill.integrationtest_mill0.9:0.4.0`
import de.tobiasroeser.mill.integrationtest._

object demo extends ScalaModule with PublishModule {
  // ...
}

object itest extends MillIntegrationTestModule {

  def millTestVersion = "0.9.3"

  def pluginsUnderTest = Seq(demo)

}

Your project should now look similar to this:

.
+-- demo/
|   +-- src/
|
+-- it/
    +-- src/
        +-- 01-first-test/
        |   +-- build.sc
        |   +-- src/
        |
        +-- 02-second-test/
            +-- build.sc

As the buildfiles build.sc in your test cases typically want to access the locally built plugin(s), the plugins publishes all plugins referenced under pluginsUnderTest to a temporary ivy repository, just before the test is executed. The mill version used in the integration test then used that temporary ivy repository.

Instead of referring to your plugin with import $ivy.'your::plugin:version', you can use the following line instead, which ensures you will use the correct locally build plugins.

// build.sc
import $exec.plugins

Effectively, at execution time, this line gets replaced by the content of plugins.sc, a file which was generated just before the test started to execute.

Please always refer to the official plugin documentation site for complete and up-to-date information.

JaCoCo - Code Coverage

Mill plugin to collect test coverage data with JaCoCo and generate reports.

JBake

Create static sites/blogs with JBake.

JBake home: https://jbake.org

Quickstart

// build.sc
import mill._
import $ivy.`de.tototec::de.tobiasroeser.mill.jbake:0.1.0`
import de.tobiasroeser.mill.jbake._

object site extends JBakeModule {

  def jbakeVersion = "2.6.4"

}

Generate the site:

bash> mill site.jbake

Start a local Web-Server on Port 8820 with the generated site:

bash> mill site.jbakeServe

JBuildInfo

This is a mill module similar to BuildInfo but for Java. It will generate a Java class containing information from your build.

To declare a module that uses this plugin, extend the com.github.carueda.mill.JBuildInfo trait and provide the desired information via the buildInfoMembers method:

// build.sc
import $ivy.`com.github.carueda::jbuildinfo:0.1.2`
import com.github.carueda.mill.JBuildInfo
import mill.T

object project extends JBuildInfo {
  def buildInfoMembers: T[Map[String, String]] = T {
    Map(
      "name" -> "some name",
      "version" -> "x.y.z"
    )
  }
}

This will generate:

// BuildInfo.java
public class BuildInfo {
  public static final String getName() { return "some name"; }
  public static final String getVersion() { return "x.y.z"; }
}

Configuration options

  • def buildInfoMembers: T[Map[String, String]]

The map containing all member names and values for the generated class.

  • def buildInfoClassName: String, default: BuildInfo

The name of the class that will contain all the members from buildInfoMembers.

  • def buildInfoPackageName: Option[String], default: None

The package name for the generated class.

Kotlin

Kotlin compiler support for mill.

Quickstart

// Load the plugin from Maven Central via ivy/coursier
import $ivy.`de.tototec::de.tobiasroeser.mill.kotlin_mill0.9:0.2.0`

import mill._
import mill.scalalib._
import mill.define._

import de.tobiasroeser.mill.kotlin._

object main extends KotlinModule {

  // Select the Kotlin version
  def kotlinVersion = "1.4.21"

  // Set additional Kotlin compiler options, e.g. the language level and annotation processor
  // Run `mill main.kotlincHelp` to get a list of supported options
  def kotlincOptions = super.kotlincOptions() ++ Seq("-verbose")

}

Documentation

For documentation please visit the mill-kotlin project page.

You will find there also a version compatibility matrix.

MDoc

Simple MDoc runner for Mill

This plugin provides a mill module that allows to execute Scala MDoc from within a mill build. Scala MDoc simply compiles properly marked Scala snippets in plain md files and optionally runs them through an interpreter, augmenting the code with the interpreter output.

millw / millw.bat - Mill Wrapper Scripts

Small script to automatically fetch and execute mill build tool.

How it works

millw is a small wrapper script around mill and works almost identical to mill. It automatically downloads a mill release into $HOME/.mill/download.

The mill version to be used will be determined by the following steps. The search ends, after the first step that results in a version.

  • If the first parameter is --mill-version, the second parameter will be used as the mill version. Example

` sh $ mill --mill-version 0.3.6 --disable-ticker version 0.3.6 `

  • If there is a file .mill-version in the working directory, it’s content will be used as mill version. The file must have only a mill version as content, no additional content or comments are supported. Example

` sh $ echo -n "0.3.6" > .mill-version sh $ mill --disable-ticker version 0.3.6 `

The values of the DEFAULT_MILL_VERSION variable inside the script will be used.

Use cases

As mill executable

Istead of installing mill, you can just place the script into you local $HOME/bin directory and rename it to mill.

If you need a special mill version in a project directory, just place a .mill-version file with the best mill version. Example: setting mill 0.3.6 as best local mill version

sh $ echo -n "0.3.6" > .mill-version

As a wrapper script in your project

To make the start for others easier or to always have the correct mill version in your CI environment, you can just place a copy of the script as millw in your project root directory.

You should change the DEFAULT_MILL_VERSION variable in that script to the correct version you want to use and add the file under version control.

MiMa

Check binary compatibility with mill.

Quickstart

Just mix-in the Mima trait into your ScalaModule. And set the previous artifacts you want to check binary compatibility.

import mill._, scalalib._

import $ivy.`com.github.lolgab::mill-mima_mill0.9:0.0.2`
import com.github.lolgab.mill.mima._

object main extends ScalaModule with Mima {

  def mimaPreviousArtifacts = Agg(
    ivy"my_group_id::main:my_previous_version"
  )

  // other settings ...

}

You can then check the binary compatibility of the module with:

> mill main.mimaReportBinaryIssues
Binary compatibility check passed.

OSGi

Produce OSGi Bundles with mill.

Quickstart

import mill._, mill.scalalib._
import $ivy.`de.tototec::de.tobiasroeser.mill.osgi:0.0.5`
import de.tobiasroeser.mill.osgi._

object project extends ScalaModule with OsgiBundleModule {

  def bundleSymbolicName = "com.example.project"

  def osgiHeaders = T{ super.osgiHeaders().copy(
    `Export-Package`   = Seq("com.example.api"),
    `Bundle-Activator` = Some("com.example.internal.Activator")
  )}

  // other settings ...

}

PowerShell Completion

Basic PowerShell completion support.

PublishM2

Since Mill 0.6.1-27-f265a4 there is a built-in publishM2Local target in PublishModule.

Mill plugin to publish artifacts into a local Maven repository.

Quickstart

Just mix-in the PublishM2Module into your project. PublishM2Module already extends mill’s built-in PublishModule.

File: build.sc

import mill._, scalalib._, publish._

import $ivy.`de.tototec::de.tobiasroeser.mill.publishM2:0.0.1`
import de.tobiasroeser.mill.publishM2._

object project extends PublishModule with PublishM2Module {
  // ...
}

Publishing to default local Maven repository

> mill project.publishM2Local
[40/40] project.publishM2Local
Publishing to /home/user/.m2/repository

Publishing to custom local Maven repository

> mill project.publishM2Local /tmp/m2repo
[40/40] project.publishM2Local
Publishing to /tmp/m2repo

ScalablyTyped

Scalablytyped support for mill.

Quickstart

Mix-in the ScalablyTyped trait into your ScalaJSModule and set-up a package.json file with your TypeScript dependencies.

import mill._, scalalib._

import $ivy.`com.github.lolgab::mill-scalablytyped::0.0.2`
import com.github.lolgab.mill.scalablytyped._

object main extends ScalaJSModule with ScalablyTyped {

  // other settings ...

}

It will run ScalablyTyped and add the converted dependencies to the module’s ivyDeps.

Scalafix

Scalafix support for mill.

Fix sources

build.sc:

import $ivy.`com.goyeau::mill-scalafix:<latest version>`
import com.goyeau.mill.scalafix.ScalafixModule
import mill.scalalib._

object project extends ScalaModule with ScalafixModule {
  def scalaVersion = "2.12.11"
}
> mill project.fix
[29/29] project.fix
/project/project/src/MyClass.scala:12:11: error: [DisableSyntax.var] mutable state should be avoided
  private var hashLength = 7
          ^^^
1 targets failed
project.fix A Scalafix linter error was reported

SCIP (SCIP Code Intelligence Protocol)

Support for generating SCIP indexes from your Mill build. This is most commonly used to power intelligent code navigation on Sourcegraph.

Quickstart

The recommended way to use mill-scip is via the scip-java cli tool that can be installed via Coursier.

cs install scip-java

Once you have scip-java installed the following command and the root of your Mill build will generate an index and place it at the root of your project.

scip-java index

You can also manually trigger this with Mill by doing the following:

mill --import ivy:io.chris-kipp::mill-scip::0.2.2 io.kipp.mill.scip.Scip/generate

This will then generate your index.scip inside of out/io/kipp/mill/scip/Scip/generate.dest/.

Shell Completions

As Mill is a tool often used from the CLI (Command line interface), you may be also interested in installing some completion support for your preferred shell:

VCS Version

Mill plugin to derive a version from (last) git tag and edit state. It may support other VCS as well.

Lots of formatting options are provided. When used with its defaults, the outcome is identical to the version scheme used by mill.

Quickstart

import mill._
import mill.scalalib._

// Load the plugin from Maven Central via ivy/coursier
import $ivy.`de.tototec::de.tobiasroeser.mill.vcs.version::0.1.2`
import de.tobiasroeser.mill.vcs.version.VcsVersion

object main extends JavaModule with PublishModule {
  override def publishVersion: T[String] = VcsVersion.vcsState().format()
}

Zsh Completion

Limited zsh completion support.

This script is part of a collection of configuration files and comes without documentation, but might be useful nonetheless, if you are a zsh user.