Scala Project Builds in Gradle, SBT, and Maven

A sample multi-module project that compiles and builds in Gradle, SBT, and Maven to show the various ways to get Scala code built.

Why Scala:

Martin Odersky -- We are in the middle of a paradigm shift [in] the industry, and there will be a new equilibrium between functional and object-driven programming, and Scala is leading that.

#Features

• Build tools of JEE, Maven and Gradle.

  • multi-module builds
  • multi-multi-multi modules builds
  • need to add Scala into these environments
  • cross compiling can be tricky, but manageable
    • mixing means java first or scala first
    • keeps things seperate, at least in main and test

• SBT is the Simple (or Scala) Build Tool

  • Default build tool for Scala,
  • Martin Odersky says Scala will continue to allow all three.

• Testing - Recommend ScalaTest

  • ScalaTest WebSite
  • Matchers Quick Reference
  • selecting a style

• JavaLib

  • running a ScalaTest as a jUnit test
  • class is ScalaTest

• ScalaLib

  • run ScalaTest in additon to jUnit
  • ScalaFeatureSpecTest
  • ScalaFlatSpecTest
  • ScalaFunSuiteTest

• Show build systems example

  • Maven
    • JavaLib - no changes
    • ScalaLib - added scalatest - pom.xml
    • mvn clean test
  • Gradle
    • build.gradle
    • JavaLib
      • add beforeTest handle to see tests when they run
    • ScalaLib
      • add scalatest plugin
    • gradle clean test
  • Sbt
    • project/build.sbt - add scalatest dependency
    • sbt clean test

• Testing code in ScalaTest

  • Pascal's Triangle
  • Possible iterations - iterative and recursive
  • PascalTriangleTest - look at examples
    • Java Iterative
      • PascalJava
      • show Java to Scala conversions of List[List[Long]]
    • Scala Recursive
      • PascalScala
      • show prettyPrint code
    • Scala worksheet - O Captian, My Captian
      • investigate a simpler algorithm
      • determine structure to use
      • need a structure to generate the next value on the fly