Merge pull request #573 from exoego/scala3

Implement Scala 3 support

.scalafmt.conf

@@ -1,3 +1,8 @@
 maxColumn = 140
 align.preset = more
-version=2.7.5
+version = 3.6.0
+project.layout = StandardConvention
+runner.dialect = scala213source3
+
+# Added to minimize changes
+docstrings.style = keep

.travis.yml

@@ -10,6 +10,7 @@ scala:
   - 2.11.12
   - 2.12.13
   - 2.13.5
+  - 3.2.0
 
 before_install:
   - git fetch --tags # needed to fetch tags
@@ -50,4 +51,4 @@ cache:
   directories:
   - $HOME/.cache/coursier
   - $HOME/.ivy2/cache
-  - $HOME/.sbt
+  - $HOME/.sbt

akka/src/test/scala/better/files/FileWatcherSpec.scala

@@ -26,7 +26,7 @@ class FileWatcherSpec extends CommonSpec {
       import java.nio.file.{StandardWatchEventKinds => Events}
       import FileWatcher._
 
-      import akka.actor.{ActorRef, ActorSystem}
+      import akka.actor._
       implicit val system = ActorSystem()
 
       val watcher: ActorRef = dir.newWatcher()

build.sbt

@@ -4,8 +4,8 @@ val repo     = "better-files"
 inThisBuild(
   List(
     organization.withRank(KeyRanks.Invisible) := "better.files",
-    homepage := Some(url(s"https://github.com/$username/$repo")),
-    licenses := List("MIT" -> url(s"https://github.com/$username/$repo/blob/master/LICENSE")),
+    homepage                                  := Some(url(s"https://github.com/$username/$repo")),
+    licenses                                  := List("MIT" -> url(s"https://github.com/$username/$repo/blob/master/LICENSE")),
     developers := List(
       Developer(
         id = username,
@@ -18,15 +18,15 @@ inThisBuild(
 )
 
 lazy val commonSettings = Seq(
-  organization := s"com.github.$username",
-  scalaVersion := crossScalaVersions.value.find(_.startsWith("2.12")).get,
-  crossScalaVersions := Seq("2.11.12", "2.12.13", "2.13.5"), // when you change this line, also change .travis.yml
-  crossVersion := CrossVersion.binary,
-  scalacOptions := myScalacOptions(scalaVersion.value, scalacOptions.value),
+  organization       := s"com.github.$username",
+  scalaVersion       := crossScalaVersions.value.find(_.startsWith("2.12")).get,
+  crossScalaVersions := Seq("2.11.12", "2.12.13", "2.13.5", "3.2.0"), // when you change this line, also change .travis.yml
+  crossVersion       := CrossVersion.binary,
+  scalacOptions      := myScalacOptions(scalaVersion.value, scalacOptions.value),
   Compile / doc / scalacOptions += "-groups",
   libraryDependencies += Dependencies.scalatest,
   Compile / compile := (Compile / compile).dependsOn(formatAll).value,
-  Test / test := (Test / test).dependsOn(checkFormat).value,
+  Test / test       := (Test / test).dependsOn(checkFormat).value,
   formatAll := {
     (Compile / scalafmt).value
     (Test / scalafmt).value
@@ -51,22 +51,32 @@ def myScalacOptions(scalaVersion: String, suggestedOptions: Seq[String]): Seq[St
 lazy val core = (project in file("core"))
   .settings(commonSettings: _*)
   .settings(
-    name := repo,
+    name        := repo,
     description := "Simple, safe and intuitive I/O in Scala",
     libraryDependencies ++= Seq(
-      Dependencies.scalaReflect(scalaVersion.value),
       Dependencies.commonsio,
-      Dependencies.fastjavaio,
-      Dependencies.shapeless
-    )
+      Dependencies.fastjavaio
+    ) ++ (CrossVersion.partialVersion(scalaVersion.value) match {
+      case Some((2, _)) =>
+        Seq(
+          Dependencies.shapeless,
+          Dependencies.scalaReflect(scalaVersion.value)
+        )
+      case _ => Seq.empty
+    })
   )
 
 lazy val akka = (project in file("akka"))
   .settings(commonSettings: _*)
   .settings(
-    name := s"$repo-akka",
+    name        := s"$repo-akka",
     description := "Reactive file watcher using Akka actors",
-    libraryDependencies += Dependencies.akka
+    libraryDependencies += (CrossVersion.partialVersion(scalaVersion.value) match {
+      // scala-steward:off
+      case Some((2, 11)) => "com.typesafe.akka" %% "akka-actor" % "2.5.32"
+      // scala-steward:on
+      case _ => Dependencies.akka
+    })
   )
   .dependsOn(core % "test->test;compile->compile")
 
@@ -80,12 +90,12 @@ lazy val root = (project in file("."))
   .aggregate(core, akka)
 
 lazy val docSettings = Seq(
-  autoAPIMappings := true,
+  autoAPIMappings                            := true,
   ScalaUnidoc / unidoc / unidocProjectFilter := inProjects(core, akka),
-  siteSourceDirectory := baseDirectory.value / "site",
-  ScalaUnidoc / siteSubdirName := "latest/api",
+  siteSourceDirectory                        := baseDirectory.value / "site",
+  ScalaUnidoc / siteSubdirName               := "latest/api",
   addMappingsToSiteDir(ScalaUnidoc / packageDoc / mappings, ScalaUnidoc / siteSubdirName),
-  git.remoteRepo := s"[email protected]:$username/$repo.git",
+  git.remoteRepo                                             := s"[email protected]:$username/$repo.git",
   ghpagesPushSite / envVars += ("SBT_GHPAGES_COMMIT_MESSAGE" -> s"Publishing Scaladoc [CI SKIP]")
 )
 

core/src/main/scala-2/better/files/ResourceScalaCompat.scala

@@ -0,0 +1,90 @@
+package better.files
+
+import scala.language.experimental.macros
+import scala.reflect.macros.{ReificationException, blackbox}
+
+private[files] trait ResourceScalaCompat {
+
+  /** Look up class resource files.
+    *
+    * This Resource looks up resources relative to the JVM class file for `T`,
+    * using [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]].
+    * For example, if `com.example.ExampleClass` is given for `T`, then resource files will be searched for in the `com/example` folder containing `ExampleClass.class`.
+    *
+    * If you want to look up resource files relative to the call site instead (that is, you want a class to look up one of its own resources), use the `my` method instead.
+    *
+    * @example {{{ Resource.at[YourClass].url("config.properties") }}}
+    * @tparam T The class, trait, or object to look up from. Objects must be written with a `.type` suffix, such as `Resource.at[SomeObject.type]`.
+    * @return A Resource for `T`.
+    * @see [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  def at[T]: Resource = macro Macros.atStaticImpl[T]
+
+  /** Look up class resource files.
+    *
+    * This Resource looks up resources from the given Class,
+    * using [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]].
+    * For example, if `classOf[com.example.ExampleClass]` is given for `clazz`, then resource files will be searched for
+    * in the `com/example` folder containing `ExampleClass.class`.
+    *
+    * If you want to look up resource files relative to the call site instead (that is, you want your class to look up one of its own resources),
+    * use the `my` method instead.
+    *
+    * @example {{{ Resource.at(Class.forName("your.AppClass")).url("config.properties") }}}
+    *
+    * In this example, a file named `config.properties` is expected to appear alongside the file `AppClass.class` in the package `your`.
+    * @param clazz The class to look up from.
+    * @return A Resource for `clazz`.
+    * @see [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  def at(clazz: Class[_]): Resource = macro Macros.atDynamicImpl
+
+  /** Look up own resource files.
+    *
+    * This Resource looks up resources from the [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html Class]] surrounding the call,
+    * using [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]].
+    * For example, if `my` is called from `com.example.ExampleClass`,
+    * then resource files will be searched for in the `com/example` folder containing `ExampleClass.class`.
+    *
+    * @example {{{ Resource.my.url("config.properties") }}}
+    * @return A Resource for the call site.
+    * @see [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  def my: Resource = macro Macros.myImpl
+}
+
+/** Implementations of the `Resource.at` macros. This is needed because `Class#getResource` is caller-sensitive;
+  * calls to it must appear in user code, ''not'' in better-files.
+  */
+private[files] final class Macros(val c: blackbox.Context) {
+
+  import c.universe._
+  import c.Expr
+
+  def atStaticImpl[T](implicit T: WeakTypeTag[T]): Expr[Resource] = {
+    val rtc = Expr[Class[_]] {
+      try {
+        c.reifyRuntimeClass(T.tpe, concrete = true)
+      } catch {
+        case _: ReificationException => c.abort(c.enclosingPosition, s"${T.tpe} is not a concrete type")
+      }
+    }
+    atDynamicImpl(rtc)
+  }
+
+  def atDynamicImpl(clazz: Expr[Class[_]]): Expr[Resource] =
+    reify {
+      new Resource {
+        override def url(name: String) = Option(clazz.splice.getResource(name))
+      }
+    }
+
+  def myImpl: Expr[Resource] = {
+    val rtc = c.reifyEnclosingRuntimeClass
+    if (rtc.isEmpty) {
+      // The documentation for reifyEnclosingRuntimeClass claims that this is somehow possible!?
+      c.abort(c.enclosingPosition, "this location doesn't correspond to a Java class file")
+    }
+    atDynamicImpl(Expr[Class[_]](rtc))
+  }
+}

core/src/main/scala-3/better/files/ResourceScalaCompat.scala

@@ -0,0 +1,116 @@
+package better.files
+
+import scala.quoted.{Quotes, Expr}
+import scala.quoted.*
+
+private[files] trait ResourceScalaCompat {
+
+  /** Look up class resource files.
+    *
+    * This Resource looks up resources relative to the JVM class file for `T`, using
+    * [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]. For example, if
+    * `com.example.ExampleClass` is given for `T`, then resource files will be searched for in the `com/example` folder containing
+    * `ExampleClass.class`.
+    *
+    * If you want to look up resource files relative to the call site instead (that is, you want a class to look up one of its own
+    * resources), use the `my` method instead.
+    *
+    * @example
+    *   {{{Resource.at[YourClass].url("config.properties")}}}
+    * @tparam T
+    *   The class, trait, or object to look up from. Objects must be written with a `.type` suffix, such as `Resource.at[SomeObject.type]`.
+    * @return
+    *   A Resource for `T`.
+    * @see
+    *   [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  inline def at[T]: Resource = ${ Macros.atStaticImpl[T] }
+
+  /** Look up class resource files.
+    *
+    * This Resource looks up resources from the given Class, using
+    * [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]. For example, if
+    * `classOf[com.example.ExampleClass]` is given for `clazz`, then resource files will be searched for in the `com/example` folder
+    * containing `ExampleClass.class`.
+    *
+    * If you want to look up resource files relative to the call site instead (that is, you want your class to look up one of its own
+    * resources), use the `my` method instead.
+    *
+    * @example
+    *   {{{Resource.at(Class.forName("your.AppClass")).url("config.properties")}}}
+    *
+    * In this example, a file named `config.properties` is expected to appear alongside the file `AppClass.class` in the package `your`.
+    * @param clazz
+    *   The class to look up from.
+    * @return
+    *   A Resource for `clazz`.
+    * @see
+    *   [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  def at(clazz: Class[_]): Resource = new Resource {
+    override def url(name: String) = Option(clazz.getResource(name))
+  }
+
+  /** Look up own resource files.
+    *
+    * This Resource looks up resources from the [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html Class]] surrounding the
+    * call, using [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]. For
+    * example, if `my` is called from `com.example.ExampleClass`, then resource files will be searched for in the `com/example` folder
+    * containing `ExampleClass.class`.
+    *
+    * @example
+    *   {{{Resource.my.url("config.properties")}}}
+    * @return
+    *   A Resource for the call site.
+    * @see
+    *   [[https://docs.oracle.com/javase/10/docs/api/java/lang/Class.html#getResource(java.lang.String) Class#getResource]]
+    */
+  inline def my: Resource = ${ Macros.myImpl }
+}
+
+private[files] object Macros {
+
+  def atStaticImpl[T: Type](using qc: Quotes): Expr[Resource] = {
+    import qc.reflect.*
+    val tpe           = TypeRepr.of[T]
+    val typeSymbolStr = tpe.typeSymbol.toString
+    if (typeSymbolStr.startsWith("class ") || typeSymbolStr.startsWith("module class ")) {
+      val baseClass = tpe.baseClasses.head
+      return '{
+        new Resource {
+          override def url(name: String) = Option(
+            Class
+              .forName(${
+                Expr(baseClass.fullName)
+              })
+              .getResource(name)
+          )
+        }
+      }
+    } else {
+      report.errorAndAbort(s"${tpe.show} is not a concrete type")
+    }
+  }
+
+  def myImpl(using qc: Quotes): Expr[Resource] = {
+    import qc.reflect.*
+    var callee = Symbol.spliceOwner
+    while (callee != null && callee != Symbol.noSymbol) {
+      callee = callee.owner
+      if (callee.isClassDef) {
+        return '{
+          new Resource {
+            override def url(name: String) = Option(
+              Class
+                .forName(${
+                  Expr(callee.fullName)
+                })
+                .getResource(name)
+            )
+          }
+        }
+      }
+    }
+    report.errorAndAbort("this location doesn't correspond to a Java class file")
+  }
+}