Implement conversion from/to native JS objects.

build.sbt

@@ -73,6 +73,11 @@ lazy val core = crossProject(JVMPlatform, JSPlatform, NativePlatform)
       "org.scalatest" %%% "scalatest" % scalaTestVersion % Test,
     ),
   )
+  .jsSettings(
+    libraryDependencies ++= Seq(
+      "org.getshaka" %%% "native-converter" % "0.9.0",
+    ),
+  )
 
 lazy val circe = crossProject(JVMPlatform, JSPlatform, NativePlatform)
   .crossType(CrossType.Pure)

modules/core/.js/src/main/scala/com/github/tarao/record4s/ArrayRecordPlatformSpecific.scala

@@ -0,0 +1,23 @@
+package com.github.tarao.record4s
+
+import org.getshaka.nativeconverter.NativeConverter
+import scala.scalajs.js
+
+trait ArrayRecordPlatformSpecific {
+  def fromJS[T <: Tuple](obj: js.Any)(using
+    nc: NativeConverter[ArrayRecord[T]],
+  ): ArrayRecord[T] = nc.fromNative(obj)
+
+  def fromJSON[T <: Tuple](json: String)(using
+    nc: NativeConverter[ArrayRecord[T]],
+  ): ArrayRecord[T] = nc.fromJson(json)
+
+  extension [R](record: ArrayRecord[R]) {
+    def toJS(using NativeConverter[ArrayRecord[R]]): js.Any = record.toNative
+
+    def toJSON(using NativeConverter[ArrayRecord[R]]): String = record.toJson
+  }
+
+  inline given nativeConverter[R]: NativeConverter[ArrayRecord[R]] =
+    NativeConverter.derived
+}

modules/core/.js/src/main/scala/com/github/tarao/record4s/RecordPlatformSpecific.scala

@@ -0,0 +1,88 @@
+package com.github.tarao.record4s
+
+import org.getshaka.nativeconverter.{NativeConverter, ParseState}
+import scala.compiletime.{constValue, erasedValue, summonInline}
+import scala.scalajs.js
+
+trait RecordPlatformSpecific {
+  def fromJS[R <: %](obj: js.Any)(using nc: NativeConverter[R]): R =
+    nc.fromNative(obj)
+
+  def fromJSON[R <: %](json: String)(using nc: NativeConverter[R]): R =
+    nc.fromJson(json)
+
+  extension [R <: %](record: R) {
+    def toJS(using NativeConverter[R]): js.Any = record.toNative
+
+    def toJSON(using NativeConverter[R]): String = record.toJson
+  }
+
+  private type ImplicitlyJsAny =
+    String | Boolean | Byte | Short | Int | Float | Double | Null | js.Any
+
+  private inline def fieldsToNative[Types, Labels](
+    record: Map[String, Any],
+    res: js.Dynamic = js.Object().asInstanceOf[js.Dynamic],
+  ): js.Any =
+    inline (erasedValue[Types], erasedValue[Labels]) match {
+      case _: (EmptyTuple, EmptyTuple) =>
+        res
+
+      case _: (tpe *: types, label *: labels) =>
+        val labelStr = constValue[label & String]
+        val nativeElem =
+          inline erasedValue[tpe] match {
+            case _: ImplicitlyJsAny =>
+              record(labelStr).asInstanceOf[js.Any]
+            case _ =>
+              val nc = summonInline[NativeConverter[tpe]]
+              val elem = record(labelStr).asInstanceOf[tpe]
+              nc.toNative(elem)
+          }
+        res.updateDynamic(labelStr)(nativeElem)
+
+        fieldsToNative[types, labels](record, res)
+    }
+
+  private inline def nativeToFields[Types, Labels](
+    dict: js.Dictionary[js.Any],
+    ps: ParseState,
+    res: Seq[(String, Any)] = Seq.empty,
+  ): Seq[(String, Any)] =
+    inline (erasedValue[Types], erasedValue[Labels]) match {
+      case _: (EmptyTuple, EmptyTuple) =>
+        res
+
+      case _: (tpe *: types, label *: labels) =>
+        val nc = summonInline[NativeConverter[tpe]]
+        val labelStr = constValue[label & String]
+        val jsElem = dict.getOrElse(labelStr, null)
+        val elem = nc.fromNative(ps.atKey(labelStr, jsElem))
+        nativeToFields[types, labels](dict, ps, res :+ (labelStr, elem))
+    }
+
+  private def asDict(ps: ParseState): js.Dictionary[js.Any] =
+    ps.json match {
+      case o: js.Object => o.asInstanceOf[js.Dictionary[js.Any]]
+      case _            => ps.fail("js.Object")
+    }
+
+  inline given nativeConverter[R <: %](using
+    r: RecordLike[R],
+  ): NativeConverter[R] = {
+    type Types = r.ElemTypes
+    type Labels = r.ElemLabels
+
+    new NativeConverter[R] {
+      extension (record: R) {
+        def toNative: js.Any =
+          fieldsToNative[Types, Labels](r.iterableOf(record).toMap)
+      }
+
+      def fromNative(ps: ParseState): R = {
+        val iterable = nativeToFields[Types, Labels](asDict(ps), ps)
+        Record.newMapRecord[R](iterable)
+      }
+    }
+  }
+}

modules/core/.js/src/test/scala/com/github/tarao/record4s/JSArrayRecordSpec.scala

@@ -0,0 +1,183 @@
+package com.github.tarao.record4s
+
+import scala.scalajs.js
+
+class JSArrayRecordSpec extends helper.UnitSpec {
+  describe("ArrayRecord in JS") {
+    describe("fromJS") {
+      it("should convert js.Any to ArrayRecord") {
+        val obj: js.Any = js.Dynamic.literal(name = "tarao", age = 3)
+        val r = ArrayRecord.fromJS[(("name", String), ("age", Int))](obj)
+        r shouldStaticallyBe a[ArrayRecord[(("name", String), ("age", Int))]]
+        r.name shouldBe "tarao"
+        r.age shouldBe 3
+      }
+
+      it("should convert js.Any to nested ArrayRecord") {
+        val obj: js.Any = js
+          .Dynamic
+          .literal(
+            name = "tarao",
+            age  = 3,
+            email = js
+              .Dynamic
+              .literal(
+                local  = "tarao",
+                domain = "example.com",
+              ),
+          )
+        val r = ArrayRecord.fromJS[
+          (
+            ("name", String),
+            ("age", Int),
+            ("email", ArrayRecord[(("local", String), ("domain", String))]),
+          ),
+        ](obj)
+        r shouldStaticallyBe a[ArrayRecord[
+          (
+            ("name", String),
+            ("age", Int),
+            ("email", ArrayRecord[(("local", String), ("domain", String))]),
+          ),
+        ]]
+        r.name shouldBe "tarao"
+        r.age shouldBe 3
+        r.email.local shouldBe "tarao"
+        r.email.domain shouldBe "example.com"
+      }
+
+      it("should ignore extra fields") {
+        val obj: js.Any = js.Dynamic.literal(name = "tarao", age = 3)
+        val r = ArrayRecord.fromJS[("name", String) *: EmptyTuple](obj)
+        r shouldStaticallyBe a[ArrayRecord[("name", String) *: EmptyTuple]]
+        r.name shouldBe "tarao"
+        "r.age" shouldNot typeCheck
+      }
+
+      it("should fill nulls for missing fields") {
+        val obj: js.Any = js.Dynamic.literal()
+        val r = ArrayRecord.fromJS[(("name", String), ("age", Int))](obj)
+        r shouldStaticallyBe a[ArrayRecord[(("name", String), ("age", Int))]]
+        r.name shouldBe null
+        r.age shouldBe 0
+      }
+
+      it("should throw if an object field is missing") {
+        val obj: js.Any = js.Dynamic.literal(name = "tarao", age = 3)
+        a[java.lang.RuntimeException] should be thrownBy
+          ArrayRecord.fromJS[
+            (
+              ("name", String),
+              ("age", Int),
+              ("email", ArrayRecord[(("local", String), ("domain", String))]),
+            ),
+          ](obj)
+      }
+    }
+
+    describe("fromJSON") {
+      it("should convert JSON String to ArrayRecord") {
+        val json = """{"name":"tarao","age":3}"""
+        val r = ArrayRecord.fromJSON[(("name", String), ("age", Int))](json)
+        r shouldStaticallyBe a[ArrayRecord[(("name", String), ("age", Int))]]
+        r.name shouldBe "tarao"
+        r.age shouldBe 3
+      }
+
+      it("should convert JSON String to nested ArrayRecord") {
+        val json =
+          """{"name":"tarao","age":3,"email":{"local":"tarao","domain":"example.com"}}"""
+        val r = ArrayRecord.fromJSON[
+          (
+            ("name", String),
+            ("age", Int),
+            ("email", ArrayRecord[(("local", String), ("domain", String))]),
+          ),
+        ](json)
+        r shouldStaticallyBe a[ArrayRecord[
+          (
+            ("name", String),
+            ("age", Int),
+            ("email", ArrayRecord[(("local", String), ("domain", String))]),
+          ),
+        ]]
+        r.name shouldBe "tarao"
+        r.age shouldBe 3
+        r.email.local shouldBe "tarao"
+        r.email.domain shouldBe "example.com"
+      }
+
+      it("should ignore extra fields") {
+        val json = """{"name":"tarao","age":3}"""
+        val r = ArrayRecord.fromJSON[("name", String) *: EmptyTuple](json)
+        r shouldStaticallyBe a[ArrayRecord[("name", String) *: EmptyTuple]]
+        r.name shouldBe "tarao"
+        "r.age" shouldNot typeCheck
+      }
+
+      it("should fill nulls for missing fields") {
+        val json = """{}"""
+        val r = ArrayRecord.fromJSON[(("name", String), ("age", Int))](json)
+        r shouldStaticallyBe a[ArrayRecord[(("name", String), ("age", Int))]]
+        r.name shouldBe null
+        r.age shouldBe 0
+      }
+
+      it("should throw if an object field is missing") {
+        val json = """{"name":"tarao","age":3}"""
+        a[java.lang.RuntimeException] should be thrownBy
+          ArrayRecord.fromJSON[
+            (
+              ("name", String),
+              ("age", Int),
+              ("email", ArrayRecord[(("local", String), ("domain", String))]),
+            ),
+          ](json)
+      }
+    }
+
+    describe("toJS") {
+      it("should convert ArrayRecord to js.Any") {
+        val r = ArrayRecord(name = "tarao", age = 3)
+        val obj = r.toJS
+        obj shouldStaticallyBe a[js.Any]
+        js.JSON.stringify(obj) shouldBe """{"name":"tarao","age":3}"""
+      }
+
+      it("should convert nested ArrayRecord to js.Any") {
+        val r = ArrayRecord(
+          name = "tarao",
+          age  = 3,
+          email = ArrayRecord(
+            local  = "tarao",
+            domain = "example.com",
+          ),
+        )
+        val obj = r.toJS
+        obj shouldStaticallyBe a[js.Any]
+        js.JSON.stringify(obj) shouldBe """{"name":"tarao","age":3,"email":{"local":"tarao","domain":"example.com"}}"""
+      }
+    }
+
+    describe("toJSON") {
+      it("should convert ArrayRecord to JSON String") {
+        val r = ArrayRecord(name = "tarao", age = 3)
+        val json = r.toJSON
+        json shouldBe """{"name":"tarao","age":3}"""
+      }
+
+      it("should convert nested ArrayRecord to JSON String") {
+        val r = ArrayRecord(
+          name = "tarao",
+          age  = 3,
+          email = ArrayRecord(
+            local  = "tarao",
+            domain = "example.com",
+          ),
+        )
+        val json = r.toJSON
+        json shouldBe """{"name":"tarao","age":3,"email":{"local":"tarao","domain":"example.com"}}"""
+      }
+    }
+  }
+}