sbt-buildinfo

I know this because build.sbt knows this.

sbt-buildinfo generates Scala source from your build definitions.

Latest Stable

For sbt 1.x add sbt-buildinfo as a dependency in project/plugins.sbt:

addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "x.y.z")

• For sbt >= 0.13.6, see 0.11.0.
• For sbt < 0.13.6, see 0.3.2.

Usage

Add the following in your build.sbt:

lazy val root = (project in file(".")).
  enablePlugins(BuildInfoPlugin).
  settings(
    buildInfoKeys := Seq[BuildInfoKey](name, version, scalaVersion, sbtVersion),
    buildInfoPackage := "hello"
  )

When you reload the settings and compile, this generates the following:

package hello

/** This object was generated by sbt-buildinfo. */
case object BuildInfo {
  /** The value is "helloworld". */
  val name: String = "helloworld"
  /** The value is "0.1-SNAPSHOT". */
  val version: String = "0.1-SNAPSHOT"
  /** The value is "2.10.3". */
  val scalaVersion: String = "2.10.3"
  /** The value is "0.13.2". */
  val sbtVersion: String = "0.13.2"
  override val toString: String = "name: %s, version: %s, scalaVersion: %s, sbtVersion: %s".format(name, version, scalaVersion, sbtVersion)
}

As this is generated source it will be found under target, specifically for a Scala 2.11 project under target/scala-2.11/src_managed/main/sbt-buildinfo

Customize buildInfoKeys by adding whatever keys you want to have in BuildInfo. You can use BuildInfoKey.map to change the generated field name and value, add new fields with tuples, or add new fields with values computed at build-time. Note: BuildInfoKey.map can handle both SettingKey[T] and TaskKey[T] types as arguments:

buildInfoKeys ++= Seq[BuildInfoKey](
  resolvers,
  Test / libraryDependencies,
  BuildInfoKey.map(name) { case (k, v) => "project" + k.capitalize -> v.capitalize },
  "custom" -> 1234, // computed at project load time
  BuildInfoKey.action("buildTime") {
    System.currentTimeMillis
  } // re-computed each time at compile
)

This generates:

  /** The value is Seq("Sonatype Public: https://oss.sonatype.org/content/groups/public"). */
  val resolvers: Seq[String] = Seq("Sonatype Public: https://oss.sonatype.org/content/groups/public")
  /** The value is Seq("org.scala-lang:scala-library:2.9.1", ...). */
  val test_libraryDependencies: Seq[String] = Seq("org.scala-lang:scala-library:2.9.1", ...)
  /** The value is "Helloworld". */
  val projectName = "Helloworld"
  /** The value is 1234. */
  val custom = 1234
  /** The value is 1346906092160L. */
  val buildTime = 1346906092160L

Tasks can be added only if they do not depend on sourceGenerators. Otherwise, it will cause an infinite loop.

Here's how to change the generated object name:

buildInfoObject := "Info"

This changes the generated object name to object Info. Changing the object name is optional, but to avoid name clash with other jars, package name should be unique. Use buildInfoPackage key for this.

buildInfoPackage := "hello"

build number

A build number can be generated as follows. Note that cross building against multiple Scala would each generate a new number.

buildInfoKeys += buildInfoBuildNumber

BuildInfoOption.ToMap

Add the following option

buildInfoOptions += BuildInfoOption.ToMap

to generate toMap method:

val toMap = Map[String, Any](
  "name" -> name,
  "version" -> version,
  "scalaVersion" -> scalaVersion,
  "sbtVersion" -> sbtVersion)

BuildInfoOption.ToJson

Add the following option

buildInfoOptions += BuildInfoOption.ToJson

to generate toJson method.

BuildInfoOption.Traits

Add the following option

buildInfoOptions += BuildInfoOption.Traits("TestTrait1", "TestTrait2")

to mixin traits to the generated object.

BuildInfoOption.BuildTime

Add the following option

buildInfoOptions += BuildInfoOption.BuildTime

to add timestamp values:

/** The value is "2015-07-30 03:30:16.849-0700". */
val builtAtString: String = "2015-07-30 03:30:16.849-0700"
/** The value is 1438227016849L. */
val builtAtMillis: Long = 1438227016849L

BuildInfoOption.PackagePrivate

Set the package using buildInfoPackage and use the option BuildInfoOption.PackagePrivate

buildInfoPackage := "hello"
buildInfoOptions += BuildInfoOption.PackagePrivate

to make the generated BuildInfo object package private:

/** This object was generated by sbt-buildinfo. */
private[hello] case object BuildInfo {  
  ...
}

BuildInfoOption.ConstantValue

Add the following option

buildInfoOptions += BuildInfoOption.ConstantValue

to have all vals in the BuildInfo object declared final and without an explicit type annotation:

/** This object was generated by sbt-buildinfo. */
case object BuildInfo {
  /** The value is "helloworld". */
  final val name = "helloworld"
  ...
}

This is particular useful if the values must be constants – e.g., if you need to assign them to annotation arguments.

BuildInfoOption.ImportScalaPredef

Add the following option

buildInfoOptions += BuildInfoOption.ImportScalaPredef

to explicitly import scala.Predef._ in the generated code.

package hello

import scala.Predef._

/** This object was generated by sbt-buildinfo. */
case object BuildInfo {
  ...
}

This import is necessary only when using compiler option -Yno-imports. Please note, the generated import is not compatible when compiling with Scala 3 compiler option -source:future because import wildcards must be *.

License

MIT License