ZIO live session - simple live demo / published by https://github.com/dacr/code-examples-manager #e9ac3978-7758-4828-8497-2144664a9323/8256ebe54c2dc10c910e69e8939e2d14433dfac3

live-01.sc

// summary : ZIO live session - Hello world
// keywords : scala, zio, live, demo, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 7d6e7858-f20b-43da-a914-50027a61af79
// created-on : 2021-09-26T16:27:18+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
// ---------------------

import zio.*, zio.worksheet.*

println("Hello world !")

// ---------------------------

val logic1 = ZIO.attempt(println("Hello world!"))

logic1.unsafeRun

// ---------------------------

val logic2 = Console.printLine("Hello world!")

logic2.unsafeRun

live-02.sc

// summary : ZIO live session - Make execution resilient
// keywords : scala, zio, live, demo, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : b437a3c2-257b-4346-89fd-f6632c5d2d60
// created-on : 2021-09-26T16:27:18+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
// ---------------------

import zio.*, zio.worksheet.*, scala.util.Random.nextInt, scala.util.Try
import scala.Console.{GREEN,RED,RESET}

// 42 / nextInt(2)

Try(42 / nextInt(2))

val logic = ZIO.attempt(42 / nextInt(2))


logic
  .tapError(result => Console.printLine(s"1.${RED} FAILED$RESET"))
  .tap(result => Console.printLine(s"1.${GREEN} SUCCESS$RESET"))
  .ignore
  .unsafeRun // ONLY FOR WORKSHEET PURPOSES


logic
  .retry(Schedule.forever)
  .tapError(result => Console.printLine(s"2.${GREEN} FAILED$RESET"))
  .tap(result => Console.printLine(s"1.${GREEN} SUCCESS$RESET"))
  .unsafeRun // ONLY FOR WORKSHEET PURPOSES

live-03.sc

// summary : ZIO live session - Dealing with long running operation
// keywords : scala, zio, live, demo, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 0079acb0-25b3-4e0b-860e-b5d7d75d1699
// created-on : 2021-09-26T16:27:18+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
// ---------------------

import zio.*, zio.worksheet.*, scala.io.Source

Source.fromURL("https://www.mapland.fr/ip").mkString

val logic = ZIO.attemptBlocking(Source.fromURL("https://www.mapland.fr/ip").mkString)


logic
  .tap(result => Console.printLine(result))
  .unsafeRun


logic
  .timeout(Duration.fromMillis(100))
  .tap(resultOption => Console.printLine(resultOption.getOrElse("Nothing")))
  .unsafeRun

live-04.sc

// summary : ZIO live session - Writing a simple application - legacy versus effect-based
// keywords : scala, zio, live, demo, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : b354e541-49ea-4c6c-aa60-a6497b0ac72f
// created-on : 2021-09-26T16:27:18+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "org.slf4j:slf4j-simple:2.0.7"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "dev.zio::zio-nio:2.0.1"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
// ---------------------

// =========================================================================================
// classic legacy code

{
  import org.slf4j.LoggerFactory
  import scala.io.Source

  def app() =
    val logger      = LoggerFactory.getLogger("default")
    logger.info("Application starts")
    val fileContent = Source.fromFile("live-04.sc").getLines()
    val count       = fileContent.size
    logger.info("line count is {}", count)
    logger.info("Application ends")
    println(count)

  println(app())
}

// =========================================================================================
// effect based programming

{
  import zio.*, zio.worksheet.*
  import zio.nio.file.*

  val app = for {
    _     <- ZIO.log("Application starts")
    lines <- Files.readAllLines(Path("live-04.sc"))
    count  = lines.size
    _     <- ZIO.log(s"line count is $count")
    _     <- ZIO.log("Application ends")
    _     <- Console.printLine(count)
  } yield ()

  app.unsafeRun
}

// - both are readable in the same way !
// - but the second one is quite safer, the type signature tells us that it can fail

live-05.sc

// summary : ZIO live session - Writing a more complex application
// keywords : scala, zio, live, demo, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : fb874ad4-4adc-489a-95ba-5c16198a8782
// created-on : 2021-09-26T16:27:18+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "com.softwaremill.sttp.client3::async-http-client-backend-zio:3.8.15"
//> using dep "com.softwaremill.sttp.client3::zio-json:3.8.15"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
//> using dep "org.slf4j:slf4j-simple:2.0.7"
// ---------------------

import zio.*
import zio.json.*
import zio.worksheet.*
import sttp.client3.ziojson.*
import sttp.client3.*
import sttp.client3.asynchttpclient.zio.*

case class ClientInfo(clientIP: String, userAgent: String)
object ClientInfo:
  implicit val codec: JsonCodec[ClientInfo] = DeriveJsonCodec.gen

// -----------------------------------------------------------------------------------------
val app =
  for
    _          <- ZIO.log("Application starts")
    backend    <- ZIO.service[SttpBackend[Task, Any]]
    response   <- backend.send(basicRequest.get(uri"https://mapland.fr/clientInfo").response(asJson[ClientInfo]))
    clientInfo <- ZIO.from(response.body)
    _          <- ZIO.log(s"my ip is ${clientInfo.clientIP}")
    _          <- ZIO.log("Application ends")
  yield clientInfo


app.provideLayer(AsyncHttpClientZioBackend.layer()).unsafeRun

// -----------------------------------------------------------------------------------------

val stub =
  AsyncHttpClientZioBackend.stub
    .whenRequestMatches(_.uri.toString() == "https://mapland.fr/clientInfo")
    .thenRespond("""{"clientIP":"127.0.0.1","userAgent":"curl/42"}""")


app.provideLayer(ZLayer.succeed(stub)).unsafeRun

live.sh

#!/usr/bin/env bash
## summary : ZIO live session - simple live demo
## keywords : bash, zio, live, demo, pure-functional
## publish : gist
## authors : David Crosson
## license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
## id : e9ac3978-7758-4828-8497-2144664a9323
## created-on : 2022-06-25T19:05:22+02:00
## managed-by : https://github.com/dacr/code-examples-manager
## attachments : live-01.sc, live-02.sc, live-03.sc, live-04.sc, live-05.sc

scala-cli repl \
   --dep "fr.janalyse::zio-worksheet:2.0.13.0" \
   --dep "dev.zio::zio:2.0.13" \
   --dep "dev.zio::zio-streams:2.0.13" \
   --dep "dev.zio::zio-concurrent:2.0.13" \
   --dep "dev.zio::zio-test:2.0.13" \
   --dep "dev.zio::zio-test-scalacheck:2.0.13" \
   --dep "dev.zio::zio-nio:2.0.1" \
   --dep "dev.zio::zio-json:0.5.0" \
   --dep "com.softwaremill.sttp.client3::async-http-client-backend-zio:3.8.5" \
   --dep "com.softwaremill.sttp.client3::zio-json:3.8.5" \
   --dep "com.softwaremill.sttp.tapir::tapir-zio:1.3.0" \
   --dep "com.softwaremill.sttp.tapir::tapir-zio-http-server:1.3.0" \
   --dep "com.softwaremill.sttp.tapir::tapir-json-zio:1.3.0" \
   --dep "com.softwaremill.sttp.tapir::tapir-redoc-bundle:1.3.0" \