Major Code Cleanup

* setup clean project

.gitignore

-# Database files
-/.database
+# Emacs
+*~
+\#*\#
+/.emacs.desktop
+/.emacs.desktop.lock
+.elc
+auto-save-list
+tramp
 # Ensime
 .ensime
 .ensime_cache/
 .ensime*.log
-# Playframework
-logs
-project/project
-project/target
-target
-tmp
+# IntelliJ Idea
+*.iml
+*.ipr
+*.iws
+.idea/
+# Logfiles and rotated logfiles.
+*.log
+*.log.[0-9]*
+# MacOS
+*.DS_Store
+.AppleDouble
+.LSOverride
+Icon
+._*
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+# SBT
+target/
+lib_managed/
+src_managed/
+project/boot/
 .history
-dist
-/.idea
-/*.iml
-/out
-/.idea_modules
-/.classpath
-/.project
-/RUNNING_PID
-/.settings
-/.sass-cache
+.cache
 # Vim
 .*.sw[a-z]
 *.un~

.scalafmt.conf

+style = defaultWithAlign
+
+danglingParentheses        = true
+indentOperator             = spray
+maxColumn                  = 100
+project.excludeFilters     = [".*\\.sbt"]
+rewrite.rules              = [RedundantBraces, RedundantParens, SortImports]
+spaces.inImportCurlyBraces = true
+unindentTopLevelOperators  = true

CONTRIBUTING.md

+# Contributing to "Come out and Play"
+
+This project has adopted the [Collective Code Construction Contract
+(C4.2)](https://rfc.zeromq.org/spec:42) for contributing. Please read it
+before sending patches.
+
+### Additions to C4.2
+
+1. Please rebase your branch if the project diverges from your branch.
+
+2. Before a pull request is merged the commits done on the feature branch
+SHOULD be squashed into a single commit.
+

NOTICE

+Copyright 2017 Jens Grassel & André Schütz

README.md

-Code for the `come out an play` book!
+# Come out and Play - source code for the book
+
+This repository contains the example application that is developed in 
+the book [Come out and Play](https://leanpub.com/comeoutandplay).
+
+## License
+
+This code is open source software licensed under the
+[AGPLv3](https://www.gnu.org/licenses/agpl.html) license.
+
+## Contributing
+
+Please see the file [CONTRIBUTING.md](CONTRIBUTING.md) for detailed
+instructions how to contribute to this repository.
+

build.sbt

+// *****************************************************************************
+// Projects
+// *****************************************************************************
 
+lazy val frontend =
+  project
+    .in(file("frontend"))
+    .enablePlugins(AutomateHeaderPlugin, GitVersioning, GitBranchPrompt, PlayScala)
+    .settings(settings)
+    .settings(
+      compile in Compile := ((compile in Compile) dependsOn scalaJSPipeline).value,
+      libraryDependencies ++= Seq(
+        library.playSlick,
+        library.playSlickEvolutions,
+        library.postgresql,
+        library.scalaJsScripts,
+        library.webjarsBootstrap,
+        library.webjarsPlay,
+        library.scalaCheck % Test,
+        library.scalaTest  % Test
+      ),
+      pipelineStages in Assets := Seq(scalaJSPipeline),
+      pipelineStages := Seq(digest, gzip),
+      scalaJSProjects := Seq(client),
+      unmanagedSourceDirectories.in(Compile) := Seq(scalaSource.in(Compile).value),
+      unmanagedSourceDirectories.in(Test) := Seq(scalaSource.in(Test).value),
+      wartremoverWarnings in (Compile, compile) ++= Warts.unsafe
+    )
+    .dependsOn(sharedJvm)
 
-// Define the scala version for the project
-val scalaV = "2.11.8"
-
-lazy val frontend = (project in file("frontend")).settings(
-  scalaVersion := scalaV,
-  scalaJSProjects := Seq(scalaJs),
-  pipelineStages in Assets := Seq(scalaJSPipeline),
-  pipelineStages := Seq(digest, gzip),
-  // triggers scalaJSPipeline when using compile or continuous compilation
-  compile in Compile := ((compile in Compile) dependsOn scalaJSPipeline).value,
-  libraryDependencies ++= Seq(
-    "com.typesafe.play"       %% "play-slick"              % "2.0.2",
-    "com.typesafe.play"       %% "play-slick-evolutions"   % "2.0.2",
-    "com.vmunier"             %% "scalajs-scripts"         % "1.0.0",
-    "org.postgresql"           % "postgresql"              % "9.4.1212",
-    "org.webjars"             %% "webjars-play"            % "2.5.0",
-    "org.webjars"              % "bootstrap"               % "3.3.7"
-  )
-).enablePlugins(PlayScala).
-  dependsOn(sharedJvm)
-
-lazy val scalaJs = (project in file("scalaJs")).settings(
-  scalaVersion := scalaV,
-  persistLauncher := true,
-  persistLauncher in Test := false,
-  libraryDependencies ++= Seq(
-    "org.scala-js" %%% "scalajs-dom" % "0.9.1"
-  )
-).enablePlugins(ScalaJSPlugin, ScalaJSWeb).
-  dependsOn(sharedJs)
+lazy val client =
+  project
+    .in(file("client"))
+    .enablePlugins(AutomateHeaderPlugin, GitVersioning, GitBranchPrompt, ScalaJSPlugin, ScalaJSWeb)
+    .settings(settings)
+    .settings(
+      libraryDependencies ++= Seq(
+        "org.scala-js" %%% "scalajs-dom" % "0.9.1"
+      ),
+      persistLauncher := true,
+      persistLauncher in Test := false
+    )
+    .dependsOn(sharedJs)
 
-lazy val shared = (crossProject.crossType(CrossType.Pure) in file("shared")).
-  settings(scalaVersion := scalaV).
-  jsConfigure(_ enablePlugins ScalaJSWeb)
+lazy val shared =
+  (crossProject.crossType(CrossType.Pure) in file("shared"))
+    .settings(settings)
+    .jsConfigure(_ enablePlugins ScalaJSWeb)
 
 lazy val sharedJvm = shared.jvm
-lazy val sharedJs = shared.js
+lazy val sharedJs  = shared.js
 
-// loads the server project at sbt startup
+// Load the frontend project upon sbt startup.
 onLoad in Global := (Command.process("project frontend", _: State)) compose (onLoad in Global).value
+
+// *****************************************************************************
+// Library dependencies
+// *****************************************************************************
+
+lazy val library =
+  new {
+    object Version {
+      val bootstrap      = "3.3.7"
+      val playSlick      = "2.0.2"
+      val postgresql     = "42.0.0"
+      val scalaCheck     = "1.13.4"
+      val scalaJsScripts = "1.0.0"
+      val scalaTest      = "3.0.1"
+      val webjarsPlay    = "2.5.0-4"
+    }
+    val playSlick           = "com.typesafe.play" %% "play-slick"              % Version.playSlick
+    val playSlickEvolutions = "com.typesafe.play" %% "play-slick-evolutions"   % Version.playSlick
+    val postgresql          = "org.postgresql"    %  "postgresql"              % Version.postgresql 
+    val scalaCheck          = "org.scalacheck"    %% "scalacheck"              % Version.scalaCheck
+    val scalaJsScripts      = "com.vmunier"       %% "scalajs-scripts"         % Version.scalaJsScripts
+    val scalaTest           = "org.scalatest"     %% "scalatest"               % Version.scalaTest
+    val webjarsBootstrap    = "org.webjars"       %  "bootstrap"               % Version.bootstrap
+    val webjarsPlay         = "org.webjars"       %% "webjars-play"            % Version.webjarsPlay
+  }
+
+// *****************************************************************************
+// Settings
+// *****************************************************************************
+
+lazy val settings =
+  commonSettings ++
+  gitSettings ++
+  headerSettings
+
+lazy val commonSettings =
+  Seq(
+    scalaVersion in ThisBuild := "2.11.8",
+    organization := "de.hoshikuzu",
+    licenses += ("AGPLv3",
+                 url("https://www.gnu.org/licenses/agpl.html")),
+    mappings.in(Compile, packageBin) += baseDirectory.in(ThisBuild).value / "LICENSE" -> "LICENSE",
+    scalacOptions ++= Seq(
+      "-deprecation",
+      "-encoding", "UTF-8",
+      "-feature",
+      "-language:_",
+      "-target:jvm-1.8",
+      "-unchecked",
+//      "-Xfatal-warnings",
+      "-Xfuture",
+      "-Xlint",
+      "-Ydelambdafy:method",
+      "-Yno-adapted-args",
+      "-Ywarn-numeric-widen",
+      "-Ywarn-unused-import",
+      "-Ywarn-value-discard"
+    ),
+    javacOptions ++= Seq(
+      "-source", "1.8",
+      "-target", "1.8"
+    )
+)
+
+lazy val gitSettings =
+  Seq(
+    git.useGitDescribe := true
+  )
+
+import de.heikoseeberger.sbtheader.HeaderPattern
+import de.heikoseeberger.sbtheader.license._
+lazy val headerSettings =
+  Seq(
+    headers := Map("scala" -> AGPLv3("2017", "Jens Grassel & André Schütz"))
+  )
+

client/src/main/scala/de/hoshikuzu/client/TestApp.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package de.hoshikuzu.client
+
+import org.scalajs.dom
+import de.hoshikuzu.shared.TestMessage
+
+import scala.scalajs.js
+
+object TestApp extends js.JSApp {
+
+  def main(): Unit =
+    dom.document.getElementById("scalaJsTest").textContent = TestMessage.test
+
+}

frontend/app/Filters.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import javax.inject._
+import play.api._
+import play.api.http.HttpFilters
+import play.api.mvc._
+
+import filters.ExampleFilter
+
+/**
+  * This class configures filters that run on every request. This
+  * class is queried by Play to get a list of filters.
+  *
+  * Play will automatically use filters from any class called
+  * `Filters` that is placed the root package. You can load filters
+  * from a different class by adding a `play.http.filters` setting to
+  * the `application.conf` configuration file.
+  *
+  * @param env Basic environment settings for the current application.
+  * @param exampleFilter A demonstration filter that adds a header to
+  * each response.
+  */
+@Singleton
+class Filters @Inject()(env: Environment, exampleFilter: ExampleFilter) extends HttpFilters {
+
+  override val filters = {
+    // Use the example filter if we're running development mode. If
+    // we're running in production or test mode then don't use any
+    // filters at all.
+    if (env.mode == Mode.Dev) Seq(exampleFilter) else Seq.empty
+  }
+
+}

frontend/app/Module.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import com.google.inject.AbstractModule
+import java.time.Clock
+
+import services.{ ApplicationTimer, AtomicCounter, Counter }
+
+/**
+  * This class is a Guice module that tells Guice how to bind several
+  * different types. This Guice module is created when the Play
+  * application starts.
+
+  * Play will automatically use any class called `Module` that is in
+  * the root package. You can create modules in other locations by
+  * adding `play.modules.enabled` settings to the `application.conf`
+  * configuration file.
+  */
+class Module extends AbstractModule {
+
+  override def configure() = {
+    // Use the system clock as the default implementation of Clock
+    bind(classOf[Clock]).toInstance(Clock.systemDefaultZone)
+    // Ask Guice to create an instance of ApplicationTimer when the
+    // application starts.
+    bind(classOf[ApplicationTimer]).asEagerSingleton()
+    // Set AtomicCounter as the implementation for Counter.
+    bind(classOf[Counter]).to(classOf[AtomicCounter])
+  }
+
+}

frontend/app/controllers/Application.scala

-package controllers
-
-import play.api.mvc._
-import shared.SharedMessages
-
-class Application extends Controller {
-
-  def index = Action {
-    Ok(views.html.index(SharedMessages.itWorks))
-  }
-
-}

frontend/app/controllers/AsyncController.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package controllers
+
+import akka.actor.ActorSystem
+import javax.inject._
+import play.api._
+import play.api.mvc._
+import scala.concurrent.{ ExecutionContext, Future, Promise }
+import scala.concurrent.duration._
+
+/**
+  * This controller creates an `Action` that demonstrates how to write
+  * simple asynchronous code in a controller. It uses a timer to
+  * asynchronously delay sending a response for 1 second.
+  *
+  * @param actorSystem We need the `ActorSystem`'s `Scheduler` to
+  * run code after a delay.
+  * @param exec We need an `ExecutionContext` to execute our
+  * asynchronous code.
+  */
+@Singleton
+class AsyncController @Inject()(actorSystem: ActorSystem)(implicit exec: ExecutionContext)
+    extends Controller {
+
+  /**
+    * Create an Action that returns a plain text message after a delay
+    * of 1 second.
+    *
+    * The configuration in the `routes` file means that this method
+    * will be called when the application receives a `GET` request with
+    * a path of `/message`.
+    */
+  def message = Action.async {
+    getFutureMessage(1.second).map { msg =>
+      Ok(msg)
+    }
+  }
+
+  private def getFutureMessage(delayTime: FiniteDuration): Future[String] = {
+    val promise: Promise[String] = Promise[String]()
+    actorSystem.scheduler.scheduleOnce(delayTime) { promise.success("Hi!") }
+    promise.future
+  }
+
+}

frontend/app/controllers/CountController.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package controllers
+
+import javax.inject._
+import play.api._
+import play.api.mvc._
+
+import services.Counter
+
+/**
+  * This controller demonstrates how to use dependency injection to
+  * bind a component into a controller class. The class creates an
+  * `Action` that shows an incrementing count to users. The [[Counter]]
+  * object is injected by the Guice dependency injection system.
+  */
+@Singleton
+class CountController @Inject()(counter: Counter) extends Controller {
+
+  /**
+    * Create an action that responds with the [[Counter]]'s current
+    * count. The result is plain text. This `Action` is mapped to
+    * `GET /count` requests by an entry in the `routes` config file.
+    */
+  def count = Action { Ok(counter.nextCount().toString) }
+
+}

frontend/app/controllers/HomeController.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package controllers
+
+import javax.inject._
+import play.api._
+import play.api.mvc._
+
+import de.hoshikuzu.shared.TestMessage
+
+/**
+  * This controller creates an `Action` to handle HTTP requests to the
+  * application's home page.
+  */
+@Singleton
+class HomeController @Inject() extends Controller {
+
+  /**
+    * Create an Action to render an HTML page with a welcome message.
+    * The configuration in the `routes` file means that this method
+    * will be called when the application receives a `GET` request with
+    * a path of `/`.
+    */
+  def index = Action {
+    Ok(views.html.index(TestMessage.test))
+  }
+
+}

frontend/app/filters/ExampleFilter.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package filters
+
+import akka.stream.Materializer
+import javax.inject._
+import play.api.mvc._
+import scala.concurrent.{ ExecutionContext, Future }
+
+/**
+  * This is a simple filter that adds a header to all requests. It's
+  * added to the application's list of filters by the
+  * [[Filters]] class.
+  *
+  * @param mat This object is needed to handle streaming of requests
+  * and responses.
+  * @param exec This class is needed to execute code asynchronously.
+  * It is used below by the `map` method.
+  */
+@Singleton
+class ExampleFilter @Inject()(implicit override val mat: Materializer, exec: ExecutionContext)
+    extends Filter {
+
+  override def apply(
+      nextFilter: RequestHeader => Future[Result]
+  )(requestHeader: RequestHeader): Future[Result] =
+    // Run the next filter in the chain. This will call other filters
+    // and eventually call the action. Take the result and modify it
+    // by adding a new header.
+    nextFilter(requestHeader).map { result =>
+      result.withHeaders("X-ExampleFilter" -> "foo")
+    }
+
+}

frontend/app/services/ApplicationTimer.scala

+/*
+ * Copyright (C) 2017  Jens Grassel & André Schütz