Merge pull request #430 from Wisien999/cbor-poly-codec

Add HasPolyCborCodec

Author: Roman Janusz

commons-core/src/main/scala/com/avsystem/commons/serialization/cbor/CborAdtMetadata.scala

@@ -253,3 +253,17 @@ trait CborAdtInstances[T] {
   def cborCodec: GenObjectCodec[T] =
     metadata.setup(_.validate()).adjustCodec(stdCodec)
 }
+
+trait CborAdtPolyInstances[C[_]] {
+  def stdCodec[T: GenCodec]: GenObjectCodec[C[T]]
+  def metadata[T]: CborAdtMetadata[C[T]]
+}
+
+/**
+  * Like [[HasCborCodec]] but for parameterized (generic) data types.
+  */
+abstract class HasPolyCborCodec[C[_]](implicit instances: MacroInstances[CborOptimizedCodecs, CborAdtPolyInstances[C]]) {
+  private lazy val validatedInstances = instances(CborOptimizedCodecs, this).setup(_.metadata[Nothing].validate())
+
+  implicit def codec[T: GenCodec]: GenObjectCodec[C[T]] = validatedInstances.metadata[T].adjustCodec(validatedInstances.stdCodec[T])
+}

commons-core/src/test/scala/com/avsystem/commons/serialization/cbor/CborInputOutputTest.scala

@@ -28,6 +28,15 @@ case class CustomKeysRecord(
 )
 object CustomKeysRecord extends HasCborCodec[CustomKeysRecord]
 
+@cborDiscriminator(0)
+sealed trait GenericSealedTrait[+T]
+object GenericSealedTrait extends HasPolyCborCodec[GenericSealedTrait] {
+  @cborKey(0)
+  case class Success[+T](@cborKey(1) value: T) extends GenericSealedTrait[T]
+  @cborKey(1)
+  case class Failure(@cborKey(1) message: String) extends GenericSealedTrait[Nothing]
+}
+
 @cborDiscriminator(0)
 sealed trait CustomKeysFlatUnion extends Product with Serializable
 object CustomKeysFlatUnion extends HasCborCodec[CustomKeysFlatUnion] {
@@ -211,6 +220,9 @@ class CborInputOutputTest extends AnyFunSuite {
   test("chunked byte string") {
     assert(CborInput.readRawCbor[Bytes](RawCbor.fromHex("5F426162426162426162FF")) == Bytes("ababab"))
   }
+
+  roundtrip[GenericSealedTrait[Int]](GenericSealedTrait.Success[Int](234), "A200000118EA")
+  roundtrip[GenericSealedTrait[Boolean]](GenericSealedTrait.Failure("error"), "A2000101656572726F72")
 }
 
 class CborGenCodecRoundtripTest extends GenCodecRoundtripTest {