Building Scala code #

SBT, along with Maven, is a default way to build Scala applications. build.sbt is the file that defines how your project is built, but sometimes you’ll also see build.scala files in specific projects.

build.scala is the more advanced version of the build.sbt file, and often is used for more complicated projects.

Here’s an example of the difference between .sbt and .scala build files:

build.sbt

name := "hello"

version := "1.0"

build.scala

import sbt._
import Keys._

object Build extends Build {
  lazy val root = Project(id = "root", base = file(".")).settings(
    name := "hello",
    version := "1.0"      
  )
}

From the official docs

The recommended approach is to define most settings in a multi-project build.sbt file, and using project/*.scala files for task implementations or to share values, such as keys. The use of .scala files also depends on how comfortable you or your team are with Scala.

Here’s another great doc on sbt vs Scala files.

An important note is that this functionality is deprecated as of sbt 0.13.12. Here’s more about how these two files work together