feat(scala3): WIP working on scala 3 cross compilation. playframework…

…#390.

.travis.yml

@@ -28,6 +28,12 @@ jobs:
         - SCALA_VERSION=2.13.7
         - ADOPTOPENJDK=11
 
+    - name: "Run tests with Scala 3 and AdoptOpenJDK 11"
+      script: scripts/test-code.sh
+      env:
+        - TRAVIS_SCALA_VERSION=3.1.0
+        - ADOPTOPENJDK=11
+
     - name: "Run tests with Scala 2.12 and AdoptOpenJDK 8"
       script: scripts/test-code.sh
       env:
@@ -40,6 +46,12 @@ jobs:
         - SCALA_VERSION=2.13.7
         - ADOPTOPENJDK=8
 
+    - name: "Run tests with Scala 3 and AdoptOpenJDK 8"
+      script: scripts/test-code.sh
+      env:
+        - TRAVIS_SCALA_VERSION=3.1.0
+        - ADOPTOPENJDK=8
+
     - stage: docs
       script: scripts/validate-docs.sh
       name: "Validate documentation"

api/shared/src/main/scala-2.13/play/twirl/api/BaseScalaTemplate.scala

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl.api
+
+import java.util.Optional
+import scala.collection.immutable
+import scala.jdk.CollectionConverters._
+import scala.reflect.ClassTag
+
+case class BaseScalaTemplate[T <: Appendable[T], F <: Format[T]](format: F) {
+  // The overloaded methods are here for speed. The compiled templates
+  // can take advantage of them for a 12% performance boost
+  def _display_(x: AnyVal): T            = format.escape(x.toString)
+  def _display_(x: String): T            = if (x eq null) format.empty else format.escape(x)
+  def _display_(x: Unit): T              = format.empty
+  def _display_(x: scala.xml.NodeSeq): T = if (x eq null) format.empty else format.raw(x.toString())
+  def _display_(x: T): T                 = if (x eq null) format.empty else x
+
+  def _display_(o: Any)(implicit m: ClassTag[T]): T = {
+    o match {
+      case escaped if escaped != null && escaped.getClass == m.runtimeClass => escaped.asInstanceOf[T]
+      case ()                                                               => format.empty
+      case None                                                             => format.empty
+      case Some(v)                                                          => _display_(v)
+      case key: Optional[_] =>
+        (if (key.isPresent) Some(key.get) else None) match {
+          case None    => format.empty
+          case Some(v) => _display_(v)
+          case _       => format.empty
+        }
+      case xml: scala.xml.NodeSeq       => format.raw(xml.toString())
+      case escapeds: immutable.Seq[_]   => format.fill(escapeds.map(_display_))
+      case escapeds: TraversableOnce[_] => format.fill(escapeds.iterator.map(_display_).toList)
+      case escapeds: Array[_]           => format.fill(escapeds.view.map(_display_).toList)
+      case escapeds: java.util.List[_] =>
+        format.fill(escapeds.asScala.map(_display_).toList)
+      case string: String => format.escape(string)
+      case v if v != null => format.escape(v.toString)
+      case _              => format.empty
+    }
+  }
+}

api/shared/src/main/scala-2.13/play/twirl/api/TwirlHelperImports.scala

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl.api
+
+import scala.language.implicitConversions
+
+/**
+ * Imports for useful Twirl helpers.
+ */
+object TwirlHelperImports {
+
+  /** Allows Java collections to be used as if they were Scala collections. */
+  implicit def twirlJavaCollectionToScala[T](x: java.lang.Iterable[T]): Iterable[T] = {
+    import scala.jdk.CollectionConverters._
+    x.asScala
+  }
+
+  /** Allows inline formatting of java.util.Date */
+  implicit class TwirlRichDate(date: java.util.Date) {
+    def format(pattern: String): String = {
+      new java.text.SimpleDateFormat(pattern).format(date)
+    }
+  }
+
+  /** Adds a when method to Strings to control when they are rendered. */
+  implicit class TwirlRichString(string: String) {
+    def when(predicate: => Boolean): String = {
+      predicate match {
+        case true  => string
+        case false => ""
+      }
+    }
+  }
+}

api/shared/src/main/scala-2.13/play/twirl/api/package.scala

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl
+
+import scala.reflect.ClassTag
+
+package object api {
+
+  /**
+   * Brings the template engine as a
+   * [[http://docs.scala-lang.org/overviews/core/string-interpolation.html string interpolator]].
+   *
+   * Basic usage:
+   *
+   * {{{
+   *   import play.twirl.api.StringInterpolation
+   *
+   *   val name = "Martin"
+   *   val htmlFragment: Html = html"&lt;div&gt;Hello \$name&lt;/div&gt;"
+   * }}}
+   *
+   * Three interpolators are available: `html`, `xml` and `js`.
+   */
+  implicit class StringInterpolation(val sc: StringContext) extends AnyVal {
+    def html(args: Any*): Html = interpolate(args, HtmlFormat)
+
+    def xml(args: Any*): Xml = interpolate(args, XmlFormat)
+
+    def js(args: Any*): JavaScript = interpolate(args, JavaScriptFormat)
+
+    def interpolate[A <: Appendable[A]: ClassTag](args: Seq[Any], format: Format[A]): A = {
+      StringContext.checkLengths(args, sc.parts)
+      val array       = Array.ofDim[Any](args.size + sc.parts.size)
+      val strings     = sc.parts.iterator
+      val expressions = args.iterator
+      array(0) = format.raw(strings.next())
+      var i = 1
+      while (strings.hasNext) {
+        array(i) = expressions.next()
+        array(i + 1) = format.raw(strings.next())
+        i += 2
+      }
+      new BaseScalaTemplate[A, Format[A]](format)._display_(array)
+    }
+  }
+}

api/shared/src/main/scala-3/play/twirl/api/BaseScalaTemplate.scala

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl.api
+
+import java.util.Optional
+import scala.collection.immutable
+import scala.jdk.CollectionConverters._
+import scala.reflect.ClassTag
+
+case class BaseScalaTemplate[T <: Appendable[T], F <: Format[T]](format: F) {
+  // The overloaded methods are here for speed. The compiled templates
+  // can take advantage of them for a 12% performance boost
+  def _display_(x: AnyVal): T            = format.escape(x.toString)
+  def _display_(x: String): T            = if (x eq null) format.empty else format.escape(x)
+  def _display_(x: Unit): T              = format.empty
+  def _display_(x: scala.xml.NodeSeq): T = if (x eq null) format.empty else format.raw(x.toString())
+  def _display_(x: T): T                 = if (x eq null) format.empty else x
+
+  def _display_(o: Any)(implicit m: ClassTag[T]): T = {
+    o match {
+      case escaped if escaped != null && escaped.getClass == m.runtimeClass => escaped.asInstanceOf[T]
+      case ()                                                               => format.empty
+      case None                                                             => format.empty
+      case Some(v)                                                          => _display_(v)
+      case key: Optional[_] =>
+        (if (key.isPresent) Some(key.get) else None) match {
+          case None    => format.empty
+          case Some(v) => _display_(v)
+          case null    => format.empty
+        }
+      case xml: scala.xml.NodeSeq       => format.raw(xml.toString())
+      case escapeds: immutable.Seq[_]   => format.fill(escapeds.map(_display_))
+      case escapeds: TraversableOnce[_] => format.fill(escapeds.iterator.map(_display_).toList)
+      case escapeds: Array[_]           => format.fill(escapeds.view.map(_display_).toList)
+      case escapeds: java.util.List[_] =>
+        format.fill(escapeds.asScala.map(_display_).toList)
+      case string: String => format.escape(string)
+      case v if v != null => format.escape(v.toString)
+      case null           => format.empty
+    }
+  }
+}

api/shared/src/main/scala-3/play/twirl/api/TwirlHelperImports.scala

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl.api
+
+import scala.language.implicitConversions
+
+/**
+ * Imports for useful Twirl helpers.
+ */
+object TwirlHelperImports {
+
+  /** Allows Java collections to be used as if they were Scala collections. */
+  implicit def twirlJavaCollectionToScala[T](x: java.lang.Iterable[T]): Iterable[T] = {
+    import scala.jdk.CollectionConverters._
+    x.asScala
+  }
+
+  /** Allows inline formatting of java.util.Date */
+  implicit class TwirlRichDate(date: java.util.Date) {
+    def format(pattern: String): String = {
+      new java.text.SimpleDateFormat(pattern).format(date)
+    }
+  }
+
+  /** Adds a when method to Strings to control when they are rendered. */
+  implicit class TwirlRichString(string: String) {
+    def when(predicate: => Boolean): String = {
+      predicate match {
+        case true  => string
+        case false => ""
+      }
+    }
+  }
+}

api/shared/src/main/scala-3/play/twirl/api/package.scala

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) Lightbend Inc. <https://www.lightbend.com>
+ */
+package play.twirl
+
+import scala.reflect.ClassTag
+
+package object api {
+
+  /**
+   * Brings the template engine as a
+   * [[http://docs.scala-lang.org/overviews/core/string-interpolation.html string interpolator]].
+   *
+   * Basic usage:
+   *
+   * {{{
+   *   import play.twirl.api.StringInterpolation
+   *
+   *   val name = "Martin"
+   *   val htmlFragment: Html = html"&lt;div&gt;Hello \$name&lt;/div&gt;"
+   * }}}
+   *
+   * Three interpolators are available: `html`, `xml` and `js`.
+   */
+  implicit class StringInterpolation(val sc: StringContext) extends AnyVal {
+    def html(args: Any*): Html = interpolate(args, HtmlFormat)
+
+    def xml(args: Any*): Xml = interpolate(args, XmlFormat)
+
+    def js(args: Any*): JavaScript = interpolate(args, JavaScriptFormat)
+
+    def interpolate[A <: Appendable[A]: ClassTag](args: Seq[Any], format: Format[A]): A = {
+      StringContext.checkLengths(args, sc.parts)
+      val array       = Array.ofDim[Any](args.size + sc.parts.size)
+      val strings     = sc.parts.iterator
+      val expressions = args.iterator
+      array(0) = format.raw(strings.next())
+      var i = 1
+      while (strings.hasNext) {
+        array(i) = expressions.next()
+        array(i + 1) = format.raw(strings.next())
+        i += 2
+      }
+      new BaseScalaTemplate[A, Format[A]](format)._display_(array)
+    }
+  }
+}

api/shared/src/main/scala/play/twirl/api/TemplateMagic.scala

@@ -17,13 +17,13 @@ object TemplateMagic {
 
   // --- IF
 
-  implicit def iterableToBoolean(x: Iterable[_]) = x != null && !x.isEmpty
-  implicit def optionToBoolean(x: Option[_])     = x != null && x.isDefined
-  implicit def stringToBoolean(x: String)        = x != null && !x.isEmpty
+  implicit def iterableToBoolean(x: Iterable[_]): Boolean = x != null && !x.isEmpty
+  implicit def optionToBoolean(x: Option[_]): Boolean     = x != null && x.isDefined
+  implicit def stringToBoolean(x: String): Boolean        = x != null && !x.isEmpty
 
   // --- JAVA
 
-  implicit def javaCollectionToScala[T](x: java.lang.Iterable[T]) = {
+  implicit def javaCollectionToScala[T](x: java.lang.Iterable[T]): Iterable[T] = {
     import scala.collection.JavaConverters._
     x.asScala
   }
@@ -42,7 +42,7 @@ object TemplateMagic {
       }
   }
 
-  implicit def anyToDefault(x: Any) = Default(x)
+  implicit def anyToDefault(x: Any): Default = Default(x)
 
   // --- DATE
 
@@ -52,7 +52,7 @@ object TemplateMagic {
     }
   }
 
-  implicit def richDate(date: java.util.Date) = new RichDate(date)
+  implicit def richDate(date: java.util.Date): RichDate = new RichDate(date)
 
   // --- STRING
 
@@ -65,5 +65,5 @@ object TemplateMagic {
     }
   }
 
-  implicit def richString(string: String) = new RichString(string)
+  implicit def richString(string: String): RichString = new RichString(string)
 }