Scala 3 support (#494)

* WIP: SBT syncs

Dependencies have been updated to versions supporting Scala 3, IntelliJ manages to sync the project, this is a nice first step.

Introduces a new source folders `scala-2` & `scala-3`, for now the assumption is that `scala-2.13+` will be included for Scala 3.

Set Scala 3 as default version.

* WIP: Read/Write Macros split

Read/Write is now split between Scala 2&3, Scala 2 compiles as before, Scala 3 is still missing an implementation.

* ScalaJSReactInterop cross compile Scala 2&3

* WIP: Core macros split

Macros in Core is now split between Scala 2&3, Scala 2 compiles as before, Scala 3 is still missing an implementation.

* wip: make more modules compile on Scala 3

* comment out tests that don't compile yet on Scala 3

* basic product derivation for reader/writer using mirrors

* readwrite: add basic sum type derivation; disable union types

* readwrite: support scala 3 union through macros

* initial impl of macros for providers and functional component name

* tests: uncomment already working ones

* readwrite: fix c&p mistakes in external props provider; use by-name implicits to fix self-ref

* readwrite: first pass on value type support

* readwrite: support recursive case classes and existing in-scope instances

* readwrite: hacky support for default values

* readwrite: move all extra type-info macros into one place

* readwrite: add fallback reader/writer to general macro

* fix cross-compilation with scala 2

* wip: restore scala-2-only tests; use scala 2.13 as default in build

* Drop scalajs 0.6 from CI matrix; bump 1.x to 1.6.0

* fix by-name implicits used in scala 2; format code

* format build files

* don't build native and vr with scala 3

* fix build format once again

* bump scalajs-dom to 2.0.0

* review comments

* Update CHANGELOG.md

* Update CHANGELOG.md

Co-authored-by: Arman Bilge <[email protected]>

Co-authored-by: Alexander Samsig <[email protected]>
Co-authored-by: Arman Bilge <[email protected]>

.github/workflows/sbt.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        scalajs: ["0.6.33", "1.5.1"]
+        scalajs: ["1.6.0"]
         es2015_enabled: ["false", "true"]
     steps:
       - name: Configure git to disable Windows line feeds

.gitignore

@@ -11,3 +11,5 @@ idea/
 .vscode/
 project/.bloop/
 publishing-setup/
+
+.bsp/

CHANGELOG.md

@@ -1,6 +1,15 @@
 # Changelog
 
 ## vNEXT
+### Highlights :tada:
++ Added preliminary Scala 3 support
+  + no `@react`/`Props`-`apply` sugar
+  + expected to require `-source:3.0-migration` and produce warnings
+  + may not encode the same props in the same way as Scala 2 version due to different encoder generation mechanism.
+
+### Breaking Changes :warning:
++ Dropped Scala.js 0.6 and upgraded 1.x line to 1.6.0 to simplify building with Scala 3.
++ Updated scalajs-dom to v2.0.0 which is cross-published for Scala 3
 
 ## [v0.6.8](https://slinky.dev)
 ### Bug Fixes :bug:

build.sbt

@@ -3,17 +3,18 @@ ThisBuild / organization := "me.shadaj"
 Global / onChangedBuildSource := ReloadOnSourceChanges
 turbo := true
 
-ThisBuild / libraryDependencies += compilerPlugin(scalafixSemanticdb)
 addCommandAlias("style", "compile:scalafix; test:scalafix; compile:scalafmt; test:scalafmt; scalafmtSbt")
 addCommandAlias(
   "styleCheck",
   "compile:scalafix --check; test:scalafix --check; compile:scalafmtCheck; test:scalafmtCheck; scalafmtSbtCheck"
 )
 
-val scala212 = "2.12.10"
-val scala213 = "2.13.2"
+val scala212 = "2.12.14"
+val scala213 = "2.13.6"
+val scala3   = "3.0.1"
 
 ThisBuild / scalaVersion := scala213
+ThisBuild / semanticdbEnabled := true
 
 lazy val slinky = project
   .in(file("."))
@@ -42,23 +43,28 @@ addCommandAlias(
 )
 
 lazy val crossScalaSettings = Seq(
-  crossScalaVersions := Seq(scala212, scala213),
-  Compile / unmanagedSourceDirectories += {
+  crossScalaVersions := Seq(scala212, scala213, scala3),
+  Compile / unmanagedSourceDirectories ++= {
     val sourceDir = (Compile / sourceDirectory).value
     CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, n)) if n >= 13 => sourceDir / "scala-2.13+"
-      case _                       => sourceDir / "scala-2.13-"
+      case Some((3, _))            => Seq(sourceDir / "scala-2.13+")
+      case Some((2, n)) if n >= 13 => Seq(sourceDir / "scala-2.13+")
+      case _                       => Seq(sourceDir / "scala-2.13-")
     }
   },
-  Test / unmanagedSourceDirectories += {
+  Test / unmanagedSourceDirectories ++= {
     val sourceDir = (Test / sourceDirectory).value
     CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, n)) if n >= 13 => sourceDir / "scala-2.13+"
-      case _                       => sourceDir / "scala-2.13-"
+      case Some((3, _))            => Seq(sourceDir / "scala-2.13+")
+      case Some((2, n)) if n >= 13 => Seq(sourceDir / "scala-2.13+")
+      case _                       => Seq(sourceDir / "scala-2.13-")
     }
   }
 )
 
+lazy val crossScala2OnlySettings =
+  (crossScalaVersions := Seq(scala212, scala213)) +: crossScalaSettings.tail
+
 lazy val librarySettings = Seq(
   scalacOptions += {
     val origVersion = version.value
@@ -68,13 +74,29 @@ lazy val librarySettings = Seq(
       s"v$origVersion"
     }
 
-    val a = baseDirectory.value.toURI
-    val g = "https://raw.githubusercontent.com/shadaj/slinky"
-    s"-P:scalajs:mapSourceURI:$a->$g/$githubVersion/${baseDirectory.value.getName}/"
+    val a   = baseDirectory.value.toURI
+    val g   = "https://raw.githubusercontent.com/shadaj/slinky"
+    val opt = if (scalaVersion.value == scala3) "-scalajs-mapSourceURI" else "-P:scalajs:mapSourceURI"
+    s"$opt:$a->$g/$githubVersion/${baseDirectory.value.getName}/"
   },
   scalacOptions ++= Seq(
-    "-Ywarn-unused:imports"
-  )
+    "-encoding",
+    "UTF-8",
+    "-feature",
+    "-language:implicitConversions"
+  ) ++ (CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((3, _)) =>
+      Seq(
+        "-unchecked",
+        "-source:3.0-migration"
+      )
+    case _ =>
+      Seq(
+        "-deprecation",
+        "-language:higherKinds",
+        "-Ywarn-unused:imports,privates,locals"
+      )
+  })
 )
 
 lazy val macroAnnotationSettings = Seq(
@@ -84,8 +106,9 @@ lazy val macroAnnotationSettings = Seq(
     else Seq.empty
   },
   libraryDependencies ++= {
-    if (scalaVersion.value == scala213) Seq.empty
-    else Seq(compilerPlugin(("org.scalamacros" % "paradise" % "2.1.1").cross(CrossVersion.full)))
+    if (scalaVersion.value == scala212)
+      Seq(compilerPlugin(("org.scalamacros" % "paradise" % "2.1.1").cross(CrossVersion.full)))
+    else Seq.empty
   }
 )
 
@@ -156,20 +179,25 @@ lazy val reactrouter =
 lazy val testRenderer = project.settings(macroAnnotationSettings, librarySettings, crossScalaSettings).dependsOn(core)
 
 lazy val native =
-  project.settings(macroAnnotationSettings, librarySettings, crossScalaSettings).dependsOn(core, testRenderer % Test)
+  project
+    .settings(macroAnnotationSettings, librarySettings, crossScala2OnlySettings)
+    .dependsOn(core, testRenderer % Test)
 
 lazy val vr =
-  project.settings(macroAnnotationSettings, librarySettings, crossScalaSettings).dependsOn(core, testRenderer % Test)
+  project
+    .settings(macroAnnotationSettings, librarySettings, crossScala2OnlySettings)
+    .dependsOn(core, testRenderer % Test)
 
 lazy val hot = project.settings(macroAnnotationSettings, librarySettings, crossScalaSettings).dependsOn(core)
 
 val scalaJSVersion =
-  Option(System.getenv("SCALAJS_VERSION")).getOrElse("0.6.33")
+  Option(System.getenv("SCALAJS_VERSION")).getOrElse("1.6.0")
 
 lazy val scalajsReactInterop = project
   .settings(
     macroAnnotationSettings,
-    librarySettings
+    librarySettings,
+    crossScalaSettings
   )
   .dependsOn(core, web % Test)
 
@@ -181,7 +209,7 @@ lazy val docsMacros = project.settings(macroAnnotationSettings).dependsOn(web, h
 lazy val docs =
   project.settings(librarySettings, macroAnnotationSettings).dependsOn(web, hot, docsMacros, reactrouter, history)
 
-updateIntellij in ThisBuild := {}
+ThisBuild / updateIntellij := {}
 val intelliJVersion = "203.6682.168" // 2020.3
 
 lazy val coreIntellijSupport = project.settings(
@@ -190,5 +218,5 @@ lazy val coreIntellijSupport = project.settings(
   ): _*
 )
 
-intellijBuild in ThisBuild := intelliJVersion
-packageMethod in ThisBuild := PackagingMethod.Skip()
+ThisBuild / intellijBuild := intelliJVersion
+ThisBuild / packageMethod := PackagingMethod.Skip()

core/build.sbt

@@ -2,7 +2,15 @@ enablePlugins(ScalaJSPlugin)
 
 name := "slinky-core"
 
-libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value
+libraryDependencies ++= {
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((2, _)) =>
+      Seq(
+        "org.scala-lang" % "scala-reflect" % scalaVersion.value
+      )
+    case _ => Seq.empty
+  }
+}
 
 scalacOptions ++= {
   if (scalaJSVersion.startsWith("0.6.")) Seq("-P:scalajs:sjsDefinedByDefault")

core/src/main/scala/slinky/core/ExternalComponent.scala → core/src/main/scala-2/slinky/core/ExternalComponent.scala

@@ -5,8 +5,6 @@ import slinky.readwrite.Writer
 
 import scala.scalajs.js
 import scala.scalajs.js.|
-import scala.language.experimental.macros
-import scala.reflect.macros.whitebox
 
 final class BuildingComponent[E, R <: js.Object](private val args: js.Array[js.Any]) extends AnyVal {
   def apply(mods: TagMod[E]*): BuildingComponent[E, R] = {
@@ -116,19 +114,3 @@ abstract class ExternalComponentNoPropsWithRefType[R <: js.Object]
     extends ExternalComponentNoPropsWithAttributesWithRefType[Nothing, R]
 
 abstract class ExternalComponentNoProps extends ExternalComponentNoPropsWithAttributes[Nothing]
-
-// same as PropsWriterProvider except it always returns the typeclass instead of nulling it out in fullOpt mode
-trait ExternalPropsWriterProvider extends js.Object
-object ExternalPropsWriterProvider {
-  def impl(c: whitebox.Context): c.Expr[ExternalPropsWriterProvider] = {
-    import c.universe._
-    val compName = c.internal.enclosingOwner.owner.asClass
-    val q"$_; val x: $typedReaderType = null" = c.typecheck(
-      q"@_root_.scala.annotation.unchecked.uncheckedStable val comp: $compName = null; val x: _root_.slinky.readwrite.Writer[comp.Props] = null"
-    ) // scalafix:ok
-    val tpcls = c.inferImplicitValue(typedReaderType.tpe.asInstanceOf[c.Type])
-    c.Expr(q"$tpcls.asInstanceOf[_root_.slinky.core.ExternalPropsWriterProvider]")
-  }
-
-  implicit def get: ExternalPropsWriterProvider = macro impl
-}

core/src/main/scala-2/slinky/core/ExternalPropsWriterProvider.scala

@@ -0,0 +1,22 @@
+package slinky.core
+
+import scala.scalajs.js
+
+import scala.language.experimental.macros
+import scala.reflect.macros.whitebox
+
+// same as PropsWriterProvider except it always returns the typeclass instead of nulling it out in fullOpt mode
+trait ExternalPropsWriterProvider extends js.Object
+object ExternalPropsWriterProvider {
+  def impl(c: whitebox.Context): c.Expr[ExternalPropsWriterProvider] = {
+    import c.universe._
+    val compName = c.internal.enclosingOwner.owner.asClass
+    val q"$_; val x: $typedReaderType = null" = c.typecheck(
+      q"@_root_.scala.annotation.unchecked.uncheckedStable val comp: $compName = null; val x: _root_.slinky.readwrite.Writer[comp.Props] = null"
+    ) // scalafix:ok
+    val tpcls = c.inferImplicitValue(typedReaderType.tpe.asInstanceOf[c.Type])
+    c.Expr(q"$tpcls.asInstanceOf[_root_.slinky.core.ExternalPropsWriterProvider]")
+  }
+
+  implicit def get: ExternalPropsWriterProvider = macro impl
+}

core/src/main/scala-2/slinky/core/FunctionalComponentName.scala

@@ -0,0 +1,31 @@
+package slinky.core
+
+import scala.language.experimental.macros
+import scala.reflect.macros.whitebox
+
+final class FunctionalComponentName(val name: String) extends AnyVal
+object FunctionalComponentName {
+  implicit def get: FunctionalComponentName = macro FunctionalComponentNameMacros.impl
+}
+
+object FunctionalComponentNameMacros {
+  def impl(c: whitebox.Context): c.Expr[FunctionalComponentName] = {
+    import c.universe._
+
+    // from lihaoyi/sourcecode
+    def isSyntheticName(name: String) =
+      name == "<init>" || (name.startsWith("<local ") && name.endsWith(">")) || name == "component"
+
+    @scala.annotation.tailrec
+    def findNonSyntheticOwner(current: Symbol): Symbol =
+      if (isSyntheticName(current.name.decodedName.toString.trim)) {
+        findNonSyntheticOwner(current.owner)
+      } else {
+        current
+      }
+
+    c.Expr(
+      q"new _root_.slinky.core.FunctionalComponentName(${findNonSyntheticOwner(c.internal.enclosingOwner).name.decodedName.toString})"
+    )
+  }
+}

core/src/main/scala-2/slinky/core/StateReaderProvider.scala

@@ -0,0 +1,23 @@
+package slinky.core
+
+import scala.scalajs.js
+
+import scala.language.experimental.macros
+import scala.reflect.macros.whitebox
+
+trait StateReaderProvider extends js.Object
+object StateReaderProvider {
+  def impl(c: whitebox.Context): c.Expr[StateReaderProvider] = {
+    import c.universe._
+    val compName = c.internal.enclosingOwner.owner.asClass
+    val q"$_; val x: $typedReaderType = null" = c.typecheck(
+      q"@_root_.scala.annotation.unchecked.uncheckedStable val comp: $compName = null; val x: _root_.slinky.readwrite.Reader[comp.State] = null"
+    ) // scalafix:ok
+    val tpcls = c.inferImplicitValue(typedReaderType.tpe.asInstanceOf[c.Type], silent = false)
+    c.Expr(
+      q"if (_root_.scala.scalajs.LinkingInfo.productionMode) null else $tpcls.asInstanceOf[_root_.slinky.core.StateReaderProvider]"
+    )
+  }
+
+  implicit def get: StateReaderProvider = macro impl
+}

core/src/main/scala-2/slinky/core/StateWriterProvider.scala

@@ -0,0 +1,23 @@
+package slinky.core
+
+import scala.scalajs.js
+
+import scala.language.experimental.macros
+import scala.reflect.macros.whitebox
+
+trait StateWriterProvider extends js.Object
+object StateWriterProvider {
+  def impl(c: whitebox.Context): c.Expr[StateWriterProvider] = {
+    import c.universe._
+    val compName = c.internal.enclosingOwner.owner.asClass
+    val q"$_; val x: $typedReaderType = null" = c.typecheck(
+      q"@_root_.scala.annotation.unchecked.uncheckedStable val comp: $compName = null; val x: _root_.slinky.readwrite.Writer[comp.State] = null"
+    ) // scalafix:ok
+    val tpcls = c.inferImplicitValue(typedReaderType.tpe.asInstanceOf[c.Type], silent = false)
+    c.Expr(
+      q"if (_root_.scala.scalajs.LinkingInfo.productionMode) null else $tpcls.asInstanceOf[_root_.slinky.core.StateWriterProvider]"
+    )
+  }
+
+  implicit def get: StateWriterProvider = macro impl
+}

core/src/main/scala-3/slinky/core/ComponentWrapper.scala

@@ -0,0 +1,6 @@
+package slinky.core
+
+abstract class ComponentWrapper(implicit sr: => StateReaderProvider, sw: => StateWriterProvider)
+    extends BaseComponentWrapper(sr, sw) {
+  override type Definition = DefinitionBase[Props, State, Snapshot]
+}