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Running Scala 2.13 - IntelliSense is not available

You should define an object named Solution that extends App, like so:

object Solution extends App { for (i <- 0 until 5) println("Hello, world!") }
Code language: Scala (scala)

Alternatively, you can forego using the App trait helper and define main yourself:

object Solution { def main(args: Array[String]) = { println("Hello, world!") } }
Code language: Scala (scala)

We include the Scala testing libraries ScalaCheck and ScalaTest for your convenience. Here’s a quick example of using ScalaTest driven by ScalaCheck generators:

import org.scalatest.freespec.AnyFreeSpec class SetSpec extends AnyFreeSpec { "A Set" - { "when empty" - { "should have size 0" in { assert(Set.empty.size === 0) } "should produce NoSuchElementException when head is invoked" in { assertThrows[NoSuchElementException] { Set.empty.head } } } } } object Solution extends App { new SetSpec().execute() }
Code language: Scala (scala)

Here’s a quick rundown of the Scala libraries we have installed:

libraryDependencies ++= Seq ( "com.chuusai" %% "shapeless" % "2.3.7", "org.scalacheck" %% "scalacheck" % "1.15.4", "org.scalactic" %% "scalactic" % "3.2.10", "org.scalamock" %% "scalamock" % "5.1.0", "org.scalatest" %% "scalatest" % "3.2.10", "org.scalaz" %% "scalaz-core" % "7.3.5", "org.typelevel" %% "cats-core" % "2.6.1" )
Code language: Scala (scala)

Additionally, these Java libraries are available. Simply import and use as desired:

  • json-simple for parsing/encoding JSON.The google code project page has some useful examples.
  • guava provides immutable collections and other handy utility classes.
  • junit, the gold standard for testing in Java, but quite usable in Scala as well.import org.junit.Test
import org.junit.Test import org.junit.runner.JUnitCore import org.junit.Assert class TestClass { @Test def testNoop() = { Assert.assertTrue(true) } } object Solution { def main(args: Array[String]) = { JUnitCore.main("TestClass") } }
Code language: Scala (scala)
  • jMock, a library to assist with mocking in Java. The homepage has some useful examples, and can be adapted for Scala, too.

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