Migrate to Scala 3

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
   build:
     name: "Build"
     runs-on: ubuntu-20.04
-    timeout-minutes: 30
+    timeout-minutes: 10
     steps:
 
     - uses: actions/[email protected]

.scalafmt.conf

@@ -1,5 +1,9 @@
-runner.dialect=scala213source3
-version = 3.7.2
+version = 3.8.3
+
+runner.dialect=scala3
+runner.dialectOverride.allowSignificantIndentation = false
+runner.dialectOverride.allowQuietSyntax = true
+
 maxColumn = 100
 align.preset = some
 
@@ -17,6 +21,10 @@ assumeStandardLibraryStripMargin = true
 
 trailingCommas = "multiple"
 
+project {
+  git = true
+}
+
 rewrite.rules = [
   RedundantBraces,
   RedundantParens,

build.sbt

@@ -14,6 +14,12 @@ inThisBuild(
   )
 )
 
+val ScalaLTS = "3.3.4"
+val ScalaNext = "3.5.2"
+
+ThisBuild / scalaVersion := ScalaNext
+ThisBuild / versionScheme := Some("early-semver")
+
 import scala.sys.process.*
 
 def crossPlugin(
@@ -30,13 +36,6 @@ val compilerPlugins =
             crossPlugin("org.typelevel" % "kind-projector" % "0.13.3")
           ))
 
-ThisBuild / versionScheme := Some("early-semver")
-
-Global / onChangedBuildSource := ReloadOnSourceChanges
-
-ThisBuild / scalaVersion := "2.13.15"
-ThisBuild / crossScalaVersions := Seq("2.13.15")
-
 // For coursier's "latest.integration"
 ThisBuild / dynverSeparator := "-"
 
@@ -54,8 +53,25 @@ val commonSettings = Seq(
   compilerPlugins,
   scalacOptions -= "-Xfatal-warnings",
   scalacOptions -= "-Vtype-diffs",
-  scalacOptions += "-Wnonunit-statement",
-  scalacOptions ++= Seq("-Xsource:3.0"),
+  scalacOptions -= "-language:existentials",
+  // https://github.com/lampepfl/dotty/issues/18674
+  Test / scalacOptions -= "-Wunused:implicits",
+  Test / scalacOptions -= "-Wunused:explicits",
+  Test / scalacOptions -= "-Wunused:imports",
+  Test / scalacOptions -= "-Wunused:locals",
+  Test / scalacOptions -= "-Wunused:params",
+  Test / scalacOptions -= "-Wunused:privates",
+  //
+  scalacOptions += "-no-indent",
+  scalacOptions ++= {
+    if (scalaVersion.value.startsWith("3.5"))
+      Seq(
+        // for cats-tagless macros
+        "-experimental"
+      )
+    else
+      Nil
+  },
   Test / scalacOptions += "-Wconf:cat=deprecation:silent,msg=Specify both message and version:silent",
   scalacOptions ++= Seq("-release", "11"),
   mimaFailOnNoPrevious := false,
@@ -73,8 +89,9 @@ lazy val pluginCore = module("plugin-core").settings(
   libraryDependencies ++= Seq(
     "com.disneystreaming.smithy4s" %% "smithy4s-http4s" % smithy4sVersion.value
   ),
-  // mimaPreviousArtifacts := Set(organization.value %% name.value % "0.3.0"),
+  // mimaPreviousArtifacts := Set(organization.value %% name.value % "0.7.0"),
   mimaPreviousArtifacts := Set.empty,
+  scalaVersion := ScalaLTS,
 )
 
 lazy val pluginSample = module("plugin-sample")
@@ -133,6 +150,7 @@ lazy val core = module("core")
       "com.disneystreaming.alloy" % "alloy-core" % "0.3.14" % Test,
       "software.amazon.smithy" % "smithy-aws-traits" % "1.52.1" % Test,
     ),
+    // todo: move this to a separate module like "examples"
     Smithy4sCodegenPlugin.defaultSettings(Test),
   )
   .enablePlugins(Smithy4sCodegenPlugin)
@@ -156,8 +174,11 @@ lazy val lsp = module("lsp")
       "io.circe" %% "circe-core" % "0.14.10",
       "org.http4s" %% "http4s-ember-client" % "0.23.29",
       "org.http4s" %% "http4s-ember-server" % "0.23.29" % Test,
-      "io.get-coursier" %% "coursier" % "2.1.14",
-      "org.typelevel" %% "cats-tagless-macros" % "0.16.2",
+      ("io.get-coursier" % "coursier" % "2.1.14")
+        .cross(CrossVersion.for3Use2_13)
+        .exclude("org.scala-lang.modules", "scala-collection-compat_2.13")
+        .exclude("com.github.plokhotnyuk.jsoniter-scala", "jsoniter-scala-core_2.13"),
+      "org.typelevel" %% "cats-tagless-core" % "0.16.2",
     ),
     buildInfoPackage := "playground.lsp.buildinfo",
     buildInfoKeys ++= Seq(version, scalaBinaryVersion),

modules/ast/src/main/scala/playground/smithyql/AST.scala

@@ -166,8 +166,7 @@ object QualifiedIdentifier {
 
   implicit val show: Show[QualifiedIdentifier] = Show.fromToString
 
-  implicit val ord: Order[QualifiedIdentifier] = Order.by(unapply(_).get)
-
+  implicit val ord: Order[QualifiedIdentifier] = Order.by(Tuple.fromProductTyped)
 }
 
 // the keywords of the clause are captured in the Prelude's useClauses list.
@@ -240,7 +239,7 @@ final case class Binding[F[_]](
 
 final case class Identifier(
   text: String
-) extends AnyVal
+)
 
 object Struct {
 

modules/ast/src/main/scala/playground/smithyql/DSL.scala

@@ -6,7 +6,7 @@ import cats.syntax.all.*
 object DSL {
 
   implicit class StringDSLOps(
-    val s: String
+    private val s: String
   ) extends AnyVal {
 
     def call(
@@ -16,7 +16,7 @@ object DSL {
       )*
     ): Query[Id] = Query[Id](
       operationName = QueryOperationName[Id](None, OperationName(s)),
-      input = struct(args: _*),
+      input = struct(args*),
     )
 
   }

modules/core/src/main/scala/playground/CompilationError.scala

@@ -111,8 +111,8 @@ sealed trait CompilationErrorDetails extends Product with Serializable {
         s"""Matching enums by value is deprecated and may be removed in the future. Use $enumName instead.""".stripMargin
       case DuplicateItem => "Duplicate item - some entries will be dropped to fit in a set shape."
       case AmbiguousService(workspaceServices) =>
-        s"""Couldn't determine service for this operation. Add a use clause, or use an explicit reference to specify the service you want to use.
-           |Available services:""".stripMargin + workspaceServices
+        """Couldn't determine service for this operation. Add a use clause, or use an explicit reference to specify the service you want to use.
+          |Available services:""".stripMargin + workspaceServices
           .sorted
           .map(UseClause[Id](_).mapK(WithSource.liftId))
           .map(Formatter.useClauseFormatter.format(_, Int.MaxValue))

modules/core/src/main/scala/playground/DynamicServiceProxy.scala

@@ -26,8 +26,6 @@ class DynamicServiceProxy[Alg[_[_, _, _, _, _]], Op[_, _, _, _, _]](
   ): FunctorInterpreter[Op, F] = {
     val grp = serviceStatic.endpoints.groupBy(_.id).fmap(_.head)
 
-    type Proxy[I, E, O, SE, EO] = I => F[O]
-
     def makeProxy[A, B](
       schemaIn: Schema[A],
       schemaOut: Schema[B],
@@ -39,7 +37,7 @@ class DynamicServiceProxy[Alg[_[_, _, _, _, _]], Op[_, _, _, _, _]](
     }
 
     val endpointMapping =
-      new smithy4s.kinds.PolyFunction5[Endpoint[Op, *, *, *, *, *], Proxy] {
+      new service.FunctorEndpointCompiler[F] {
         private val trans = serviceStatic.toPolyFunction(interp)
 
         private def applyWithStatic[I, E, O, SI, SO, STI, STE, STO, STSI, STSO](

modules/core/src/main/scala/playground/FileCompiler.scala

@@ -3,7 +3,6 @@ package playground
 import cats.Parallel
 import cats.syntax.all.*
 import cats.~>
-import playground.*
 import playground.smithyql.SourceFile
 import playground.smithyql.WithSource
 

modules/core/src/main/scala/playground/FileRunner.scala

@@ -2,7 +2,6 @@ package playground
 
 import cats.data.NonEmptyList
 import cats.syntax.all.*
-import playground.*
 import playground.smithyql.SourceFile
 import playground.smithyql.SourceRange
 import playground.smithyql.WithSource

modules/core/src/main/scala/playground/NodeEncoderVisitor.scala

@@ -169,7 +169,7 @@ object NodeEncoderVisitor extends SchemaVisitor[NodeEncoder] { self =>
   def struct[S](
     shapeId: ShapeId,
     hints: Hints,
-    fieldsRaw: Vector[Field[S, _]],
+    fieldsRaw: Vector[Field[S, ?]],
     make: IndexedSeq[Any] => S,
   ): NodeEncoder[S] = {
 
@@ -192,7 +192,7 @@ object NodeEncoderVisitor extends SchemaVisitor[NodeEncoder] { self =>
   def union[U](
     shapeId: ShapeId,
     hints: Hints,
-    alternatives: Vector[Alt[U, _]],
+    alternatives: Vector[Alt[U, ?]],
     dispatcher: Alt.Dispatcher[U],
   ): NodeEncoder[U] = dispatcher.compile(new Alt.Precompiler[NodeEncoder] {
 

modules/core/src/main/scala/playground/OperationCompiler.scala

@@ -14,6 +14,7 @@ import playground.smithyql.Query
 import playground.smithyql.WithSource
 import smithy.api
 import smithy4s.Endpoint
+import smithy4s.Hints
 import smithy4s.Service
 import smithy4s.dynamic.DynamicSchemaIndex
 import smithyql.syntax.*
@@ -22,12 +23,15 @@ import util.chaining.*
 
 trait CompiledInput {
   type _Op[_, _, _, _, _]
+  type I
   type E
   type O
+  type SI
+  type SO
   def catchError: Throwable => Option[E]
   def writeError: Option[NodeEncoder[E]]
   def writeOutput: NodeEncoder[O]
-  def op: _Op[_, E, O, _, _]
+  def op: _Op[I, E, O, SI, SO]
 }
 
 object CompiledInput {
@@ -149,8 +153,8 @@ private class ServiceCompiler[Alg[_[_, _, _, _, _]]](
   service: Service[Alg]
 ) extends OperationCompiler[IorNel[CompilationError, *]] {
 
-  private def compileEndpoint[In, Err, Out](
-    e: Endpoint[service.Operation, In, Err, Out, _, _]
+  private def compileEndpoint[In, Err, Out, SIn, SOut](
+    e: Endpoint[service.Operation, In, Err, Out, SIn, SOut]
   ): QueryCompiler[CompiledInput] = {
     val inputCompiler = e.input.compile(QueryCompilerVisitor.full)
     val outputEncoder = NodeEncoder.derive(e.output)
@@ -162,10 +166,13 @@ private class ServiceCompiler[Alg[_[_, _, _, _, _]]](
         .map { compiled =>
           new CompiledInput {
             type _Op[_I, _E, _O, _SE, _SO] = service.Operation[_I, _E, _O, _SE, _SO]
+            type I = In
             type E = Err
             type O = Out
+            type SI = SIn
+            type SO = SOut
 
-            val op: _Op[_, Err, Out, _, _] = e.wrap(compiled)
+            val op: _Op[I, E, O, SI, SO] = e.wrap(compiled)
             val writeOutput: NodeEncoder[Out] = outputEncoder
             val writeError: Option[NodeEncoder[Err]] = errorEncoder
             val catchError: Throwable => Option[Err] = e.Error.unapply(_).map(_._2)
@@ -174,12 +181,12 @@ private class ServiceCompiler[Alg[_[_, _, _, _, _]]](
   }
 
   // https://github.com/kubukoz/smithy-playground/issues/154
-  // map of endpoint names to (endpoint, input compiler)
+  // map of endpoint names to (endpoint hints, input compiler)
   private val endpoints = service
     .endpoints
     .toList
     .groupByNel(_.name)
-    .map(_.map(_.head).map(e => (e, compileEndpoint(e))))
+    .map(_.map(_.head).map(e => (e.hints, compileEndpoint(e))))
 
   // Checks the explicit service reference (if any).
   // Note that the reference should be valid thanks to MultiServiceResolver's checks.
@@ -201,10 +208,9 @@ private class ServiceCompiler[Alg[_[_, _, _, _, _]]](
 
   private def deprecatedOperationCheck(
     q: Query[WithSource],
-    endpoint: Endpoint[service.Operation, _, _, _, _, _],
+    endpointHints: Hints,
   ): IorNel[CompilationError, Unit] =
-    endpoint
-      .hints
+    endpointHints
       .get(api.Deprecated)
       .map { info =>
         CompilationError.deprecation(

modules/core/src/main/scala/playground/OperationRunner.scala

@@ -19,7 +19,6 @@ import cats.syntax.all.*
 import fs2.compression.Compression
 import org.http4s.Uri
 import org.http4s.client.Client
-import playground.*
 import playground.plugins.PlaygroundPlugin
 import playground.plugins.SimpleHttpBuilder
 import playground.smithyql.InputNode
@@ -157,7 +156,7 @@ object OperationRunner {
 
   def forServices[F[_]: StdlibRuntime: Async: Compression: std.Console](
     services: List[DynamicSchemaIndex.ServiceWrapper],
-    getSchema: ShapeId => Option[Schema[_]],
+    getSchema: ShapeId => Option[Schema[?]],
     client: Client[F],
     baseUri: F[Uri],
     awsEnv: Resource[F, AwsEnvironment[F]],
@@ -204,7 +203,7 @@ object OperationRunner {
     client: Client[F],
     baseUri: F[Uri],
     awsEnv: Resource[F, AwsEnvironment[F]],
-    schemaIndex: ShapeId => Option[Schema[_]],
+    schemaIndex: ShapeId => Option[Schema[?]],
     plugins: List[PlaygroundPlugin],
   ): Resolver[F] =
     new Resolver[F] {

modules/core/src/main/scala/playground/PlaygroundConfig.scala

@@ -2,7 +2,6 @@ package playground
 
 import cats.kernel.Eq
 import cats.syntax.all.*
-import com.github.plokhotnyuk.jsoniter_scala.core.JsonValueCodec
 import com.github.plokhotnyuk.jsoniter_scala.macros.JsonCodecMaker
 
 final case class PlaygroundConfig(
@@ -47,7 +46,9 @@ object PlaygroundConfig {
     }
 
     object BuildConfig {
-      implicit val c: JsonValueCodec[BuildConfig] = JsonCodecMaker.make
+      // note: this is flagged as an unused import if imported
+      implicit val c: com.github.plokhotnyuk.jsoniter_scala.core.JsonValueCodec[BuildConfig] =
+        JsonCodecMaker.make
 
       def fromPlaygroundConfig(
         c: PlaygroundConfig

modules/core/src/main/scala/playground/QueryCompilerVisitor.scala

@@ -219,7 +219,7 @@ object QueryCompilerVisitorInternal extends SchemaVisitor[QueryCompiler] {
   private object FieldCompiler {
 
     def compile[A](
-      field: Field[_, A]
+      field: Field[?, A]
     ): FieldCompiler[A] =
       new FieldCompiler[A] {
         override val compiler: QueryCompiler[A] = field.schema.compile(QueryCompilerVisitorInternal)
@@ -233,7 +233,7 @@ object QueryCompilerVisitorInternal extends SchemaVisitor[QueryCompiler] {
   def struct[S](
     shapeId: ShapeId,
     hints: Hints,
-    fieldsRaw: Vector[Field[S, _]],
+    fieldsRaw: Vector[Field[S, ?]],
     make: IndexedSeq[Any] => S,
   ): QueryCompiler[S] = {
     val fields = fieldsRaw
@@ -318,7 +318,7 @@ object QueryCompilerVisitorInternal extends SchemaVisitor[QueryCompiler] {
   def union[U](
     shapeId: ShapeId,
     hints: Hints,
-    alternatives: Vector[Alt[U, _]],
+    alternatives: Vector[Alt[U, ?]],
     dispatcher: Alt.Dispatcher[U],
   ): QueryCompiler[U] = {
     def handleAlt[A](
@@ -445,7 +445,7 @@ object QueryCompilerVisitorInternal extends SchemaVisitor[QueryCompiler] {
           .parTraverse { binding =>
             document.compile(binding.value).tupleLeft(binding.identifier.value.text)
           }
-          .map(Document.obj(_: _*))
+          .map(Document.obj(_*))
       case NullLiteral() => Document.nullDoc.rightIor
     }