resolve host name / published by https://github.com/dacr/code-examples-manager #35e7ef49-5ef1-48e9-b16c-f6ff78a6df03/bae3f1e70e8425f9becd526744088f508d3b977b

host.sc

// summary : resolve host name
// keywords : scala, dns, resolution, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 35e7ef49-5ef1-48e9-b16c-f6ff78a6df03
// created-on : 2020-07-01T05:11:43Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "org.scalatest::scalatest:3.2.10"
// ---------------------

import  org.scalatest.*, flatspec.*, matchers.*
import java.net.*

def getAllByName(hostname:String):List[InetAddress] = {
  InetAddress.getAllByName(hostname).toList
}

def host(hostname:String):List[String] = {
  getAllByName(hostname).map(_.getHostAddress)
}

def host4(hostname:String):List[String] = {
  getAllByName(hostname).collect {case ip:Inet4Address => ip.getHostAddress}
}

def host6(hostname:String):List[String] = {
  getAllByName(hostname).collect {case ip:Inet6Address => ip.getHostAddress}
}


object UnitTests extends AnyFlatSpec with should.Matchers {
  override def suiteName: String = "UnitTests"

  "host functions using native (limited) APIs" should "resolve localhost address" in {
    host("localhost") should contain only "127.0.0.1"
  }

  it should "resolve remote host name" in {
    host("www.mapland.fr") should contain only("176.9.65.81", "2a01:4f8:150:834b:0:0:0:2")
    host4("www.mapland.fr") should contain only("176.9.65.81")
    host6("www.mapland.fr") should contain only("2a01:4f8:150:834b:0:0:0:2")
  }
}

UnitTests.execute()