From c5fe23594f66225eb18bf4e67472cd80023eb448 Mon Sep 17 00:00:00 2001 From: Jakob Odersky Date: Thu, 8 Mar 2018 16:53:44 -0800 Subject: Refactor build to use sbt-crossproject --- shared/src/main/scala/DerivedFormats.scala | 108 +++++++++++++++++++++ shared/src/main/scala/annotations.scala | 22 +++++ .../src/test/scala/CoproductTypeFormatTests.scala | 79 +++++++++++++++ shared/src/test/scala/FormatTests.scala | 19 ++++ .../test/scala/ImplicitDerivedFormatTests.scala | 24 +++++ shared/src/test/scala/ProductTypeFormatTests.scala | 77 +++++++++++++++ 6 files changed, 329 insertions(+) create mode 100644 shared/src/main/scala/DerivedFormats.scala create mode 100644 shared/src/main/scala/annotations.scala create mode 100644 shared/src/test/scala/CoproductTypeFormatTests.scala create mode 100644 shared/src/test/scala/FormatTests.scala create mode 100644 shared/src/test/scala/ImplicitDerivedFormatTests.scala create mode 100644 shared/src/test/scala/ProductTypeFormatTests.scala (limited to 'shared') diff --git a/shared/src/main/scala/DerivedFormats.scala b/shared/src/main/scala/DerivedFormats.scala new file mode 100644 index 0000000..d0cac38 --- /dev/null +++ b/shared/src/main/scala/DerivedFormats.scala @@ -0,0 +1,108 @@ +package spray.json + +import magnolia._ + +import scala.language.experimental.macros + +/** Mixin that enables derivation of JSON formats for any product + * (case classes) or coproduct (sealed traits) types. */ +trait DerivedFormats { self: BasicFormats => + type Typeclass[T] = JsonFormat[T] + + def combine[T](ctx: CaseClass[JsonFormat, T]): JsonFormat[T] = + new JsonFormat[T] { + override def write(value: T): JsValue = { + val fields: Seq[(String, JsValue)] = ctx.parameters.map { param => + param.label -> param.typeclass.write(param.dereference(value)) + } + JsObject(fields: _*) + } + + override def read(value: JsValue): T = value match { + case obj: JsObject => + if (ctx.isObject) { + ctx.rawConstruct(Seq.empty) + } else { + ctx.construct { param => + param.typeclass.read(obj.fields(param.label)) + } + } + case js => + deserializationError( + s"Cannot read JSON '$js' as a ${ctx.typeName.full}") + } + } + + def dispatch[T](ctx: SealedTrait[JsonFormat, T]): JsonFormat[T] = { + val typeFieldName = ctx.annotations + .collectFirst { + case g: gadt => g.typeFieldName + } + .getOrElse("type") + + new JsonFormat[T] { + override def write(value: T): JsValue = ctx.dispatch(value) { sub => + sub.typeclass.write(sub.cast(value)) match { + case obj: JsObject => + JsObject( + (Map(typeFieldName -> JsString(sub.typeName.short)) ++ + obj.fields).toSeq: _*) + case js => js + } + } + + override def read(js: JsValue): T = { + val typeName: String = js match { + case obj: JsObject if obj.fields.contains(typeFieldName) => + obj.fields(typeFieldName).convertTo[String] + case JsString(str) => + str + case _ => + deserializationError( + s"Cannot deserialize JSON to ${ctx.typeName.full} " + + "because serialized type cannot be determined.") + } + + ctx.subtypes.find(_.typeName.short == typeName) match { + case Some(tpe) => tpe.typeclass.read(js) + case None => + deserializationError( + s"Cannot deserialize JSON to ${ctx.typeName.full} " + + s"because type '${typeName}' is unsupported.") + } + } + } + } + + def jsonFormat[T]: RootJsonFormat[T] = + macro DerivedFormatMacros.derivedFormat[T] + +} +object DerivedFormats extends DerivedFormats with DefaultJsonProtocol + +trait ImplicitDerivedFormats extends DerivedFormats { self: BasicFormats => + implicit def implicitJsonFormat[T]: RootJsonFormat[T] = + macro DerivedFormatMacros.derivedFormat[T] +} +object ImplicitDerivedFormats + extends ImplicitDerivedFormats + with DefaultJsonProtocol + +object DerivedFormatMacros { + import scala.reflect.macros.whitebox._ + + /** Utility that converts a magnolia-generated JsonFormat to a RootJsonFormat. */ + def derivedFormat[T: c.WeakTypeTag](c: Context): c.Tree = { + import c.universe._ + val tpe = weakTypeOf[T].typeSymbol.asType + val sprayPkg = c.mirror.staticPackage("spray.json") + val valName = TermName(c.freshName("format")) + q"""{ + val $valName = ${Magnolia.gen[T](c)} + new $sprayPkg.RootJsonFormat[$tpe] { + def write(value: $tpe) = $valName.write(value) + def read(value: $sprayPkg.JsValue) = $valName.read(value) + } + }""" + } +} diff --git a/shared/src/main/scala/annotations.scala b/shared/src/main/scala/annotations.scala new file mode 100644 index 0000000..9d35d16 --- /dev/null +++ b/shared/src/main/scala/annotations.scala @@ -0,0 +1,22 @@ +package spray.json + +import scala.annotation.StaticAnnotation + +/** An annotation that designates that a sealed trait is a generalized algebraic + * datatype (GADT), and that a type field containing the serialized childrens' + * types should be added to the final JSON objects. + * + * Note that by default all sealed traits are treated as GADTs, with a type + * field called `type`. This annotation enables overriding the name of that + * field and is really only useful if a child itself has a field called `type` + * that would result in a conflict. + * + * Example: + * {{{ + * // the JSON field "kind" will contain the actual type of the serialized child + * @gadt("kind") sealed abstract class Keyword(`type`: String) + * case class If(`type`: String) extends Keyword(`type`) + * }}} + * @param typeFieldName the name of the field to inject into a serialized JSON + * object */ +final class gadt(val typeFieldName: String = "type") extends StaticAnnotation diff --git a/shared/src/test/scala/CoproductTypeFormatTests.scala b/shared/src/test/scala/CoproductTypeFormatTests.scala new file mode 100644 index 0000000..de73967 --- /dev/null +++ b/shared/src/test/scala/CoproductTypeFormatTests.scala @@ -0,0 +1,79 @@ +package spray.json + +import org.scalatest._ + +class CoproductTypeFormatTests + extends FlatSpec + with FormatTests + with DefaultJsonProtocol + with DerivedFormats { + + sealed trait Expr + case class Zero() extends Expr + case class Value(x: Int) extends Expr + case class Plus(lhs: Expr, rhs: Expr) extends Expr + case object One extends Expr + + implicit val exprFormat: RootJsonFormat[Expr] = jsonFormat[Expr] + + "No-parameter case class child" should behave like checkRoundtrip[Expr]( + Zero(), + """{"type":"Zero"}""" + ) + + "Simple parameter case class child" should behave like checkRoundtrip[Expr]( + Value(42), + """{"type":"Value","x":42}""" + ) + + "Nested parameter case class child" should behave like checkRoundtrip[Expr]( + Plus(Value(42), One), + """{"type":"Plus","lhs":{"type":"Value","x":42},"rhs":{"type":"One"}}""" + ) + + "Case object child" should behave like checkRoundtrip[Expr]( + One, + """{"type": "One"}""" + ) + + @gadt("kind") + sealed abstract class Keyword(`type`: String) + case class If(`type`: String) extends Keyword(`type`) + + implicit val keywordFormat: RootJsonFormat[Keyword] = jsonFormat[Keyword] + + "GADT with type field alias" should behave like checkRoundtrip[Keyword]( + If("class"), + """{"kind":"If","type":"class"}""" + ) + + @gadt("""_`crazy type!`"""") + sealed abstract trait Crazy + case class CrazyType() extends Crazy + + implicit val crazyFormat: RootJsonFormat[Crazy] = jsonFormat[Crazy] + + "GADT with special characters in type field" should behave like checkRoundtrip[ + Crazy]( + CrazyType(), + """{"_`crazy type!`\"": "CrazyType"}""" + ) + + sealed trait Enum + case object A extends Enum + case object B extends Enum + + implicit val enumFormat: RootJsonFormat[Enum] = jsonFormat[Enum] + + "Enum" should behave like checkRoundtrip[List[Enum]]( + A :: B :: Nil, + """[{"type":"A"}, {"type":"B"}]""" + ) + + "Serializing as sealed trait and deserializing as child" should "work" in { + implicit val plusFormat: RootJsonFormat[Plus] = jsonFormat[Plus] + val expr: Expr = Plus(Value(42), Plus(Zero(), One)) + assert(expr.toJson.convertTo[Plus] == expr) + } + +} diff --git a/shared/src/test/scala/FormatTests.scala b/shared/src/test/scala/FormatTests.scala new file mode 100644 index 0000000..0f56091 --- /dev/null +++ b/shared/src/test/scala/FormatTests.scala @@ -0,0 +1,19 @@ +package spray.json + +import org.scalatest._ + +trait FormatTests { self: FlatSpec => + + def checkRoundtrip[A: RootJsonFormat](a: A, expectedJson: String) = { + it should "serialize to the expected JSON value" in { + val expected: JsValue = expectedJson.parseJson + assert(a.toJson == expected) + } + + it should "serialize then deserialize back to itself" in { + val reread = a.toJson.convertTo[A] + assert(reread == a) + } + } + +} diff --git a/shared/src/test/scala/ImplicitDerivedFormatTests.scala b/shared/src/test/scala/ImplicitDerivedFormatTests.scala new file mode 100644 index 0000000..1d54ae9 --- /dev/null +++ b/shared/src/test/scala/ImplicitDerivedFormatTests.scala @@ -0,0 +1,24 @@ +package spray.json + +import org.scalatest._ + +class ImplicitDerivedFormatTests + extends FlatSpec + with FormatTests + with ImplicitDerivedFormats + with DefaultJsonProtocol { + + case class B(x: Int, b: String, mp: Map[String, Int]) + case class C(b: B) + + "Simple parameter product" should behave like checkRoundtrip( + B(42, "Hello World", Map("a" -> 1, "b" -> -1024)), + """{ "x": 42, "b": "Hello World", "mp": { "a": 1, "b": -1024 } }""" + ) + + "Nested parameter product with custom child format" should behave like checkRoundtrip( + C(B(42, "Hello World", Map("a" -> 1, "b" -> -1024))), + """{"b" :{ "x": 42, "b": "Hello World", "mp": { "a": 1, "b": -1024 } } }""" + ) + +} diff --git a/shared/src/test/scala/ProductTypeFormatTests.scala b/shared/src/test/scala/ProductTypeFormatTests.scala new file mode 100644 index 0000000..ce05000 --- /dev/null +++ b/shared/src/test/scala/ProductTypeFormatTests.scala @@ -0,0 +1,77 @@ +package spray.json + +import org.scalatest._ + +class ProductTypeFormatTests + extends FlatSpec + with FormatTests + with DerivedFormats + with DefaultJsonProtocol { + + case class A() + case class B(x: Int, b: String, mp: Map[String, Int]) + case class C(b: B) + case object D + case class E(d: D.type) + case class F(x: Int) + case class G(f: F) + + implicit val aFormat: RootJsonFormat[A] = jsonFormat[A] + implicit val bFormat: RootJsonFormat[B] = jsonFormat[B] + implicit val cFormat: RootJsonFormat[C] = jsonFormat[C] + implicit val dFormat: RootJsonFormat[D.type] = jsonFormat[D.type] + implicit val eFormat: RootJsonFormat[E] = jsonFormat[E] + + "No-parameter product" should behave like checkRoundtrip(A(), "{}") + + "Simple parameter product" should behave like checkRoundtrip( + B(42, "Hello World", Map("a" -> 1, "b" -> -1024)), + """{ "x": 42, "b": "Hello World", "mp": { "a": 1, "b": -1024 } }""" + ) + + "Nested parameter product" should behave like checkRoundtrip( + C(B(42, "Hello World", Map("a" -> 1, "b" -> -1024))), + """{"b" :{ "x": 42, "b": "Hello World", "mp": { "a": 1, "b": -1024 } } }""" + ) + + "Case object" should behave like checkRoundtrip( + D, + "{}" + ) + + "Case object as parameter" should behave like checkRoundtrip( + E(D), + """{"d":{}}""" + ) + + // custom format for F, that inverts the value of parameter x + implicit val fFormat: RootJsonFormat[F] = new RootJsonFormat[F] { + override def write(f: F): JsValue = JsObject("y" -> f.x.toJson) + override def read(js: JsValue): F = + F(js.asJsObject.fields("y").convertTo[Int]) + } + + "Overriding with a custom format" should behave like checkRoundtrip( + F(2), + """{"y":2}""" + ) + + implicit val gFormat: RootJsonFormat[G] = jsonFormat[G] + + "Derving a format with a custom child format" should behave like checkRoundtrip( + G(F(2)), + """{"f": {"y":2}}""" + ) + + case class H(x: Boolean) + case class I(h: H) + + // there is no format defined for H, Magnolia will generate one automatically + implicit val iFormat: RootJsonFormat[I] = jsonFormat[I] + + "Deriving a format that has no implicit child formats available" should behave like checkRoundtrip( + I(H(true)), + """{"h": {"x":true}}""" + ) + +} -- cgit v1.2.3