Add VersionedModelReader and VersionedModelWriter constructors (#72)

It's quite inconvenient in user code not to have constructors.
moia-oss · Nov 17, 2020 · c3551b7 · c3551b7
1 parent 63671e4
commit c3551b7
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Showing 4 changed files with 87 additions and 25 deletions.
diff --git a/build.sbt b/build.sbt
@@ -15,7 +15,7 @@ lazy val `teleproto` =
     .settings(Project.inConfig(Test)(sbtprotoc.ProtocPlugin.protobufConfigSettings): _*)
     .settings(
       name := "teleproto",
-      version := "1.9.0",
+      version := "1.10.0",
       libraryDependencies ++= Seq(
         library.scalaPB            % "protobuf",
         library.scalaPBJson        % Compile,

diff --git a/src/main/scala/io/moia/protos/teleproto/VersionedModelReader.scala b/src/main/scala/io/moia/protos/teleproto/VersionedModelReader.scala
@@ -40,16 +40,13 @@ import scala.util.{Failure, Success, Try}
   * Usage Example:
   *
   * {{{
-  * implicit val someModelReader: ModelReader[SomeDetachedModel] =
-  *    new ModelReader[MyVersion, SomeDetachedModel] {
-  *      val readerMappings: ReaderMappings =
-  *        ListMap(
-  *          VN -> readerMapping(vN.SomeApiModel),
-  *          ...
-  *          V2 -> readerMapping(v2.SomeApiModel),
-  *          V1 -> readerMapping(v1.SomeApiModel)
-  *        )
-  *    }
+  * implicit val someModelReader: VersionedModelReader[SomeDetachedModel] =
+  *   VersionedModelReader[MyVersion, SomeDetachedModel](
+  *     VN -> vN.SomeApiModel,
+  *     ...
+  *     V2 -> v2.SomeApiModel,
+  *     V1 -> v1.SomeApiModel
+  *   )
   * }}}
   */
 trait VersionedModelReader[Version, DetachedModel] {
@@ -153,4 +150,29 @@ object VersionedModelReader {
       */
     def fromJson(jsonString: String, parser: Parser): Try[PbResult[Model]] = fromJson(jsonString)
   }
+
+  def apply[Version, DetachedModel](
+      readers: (Version, CompanionReader[DetachedModel])*
+  ): VersionedModelReader[Version, DetachedModel] = new VersionedModelReader[Version, DetachedModel] {
+    val readerMappings: ReaderMappings = ListMap(readers.map { case (v, r) => r.versioned(v)(this) }: _*)
+  }
+
+  sealed trait CompanionReader[DetachedModel] {
+    type SpecificModel <: GeneratedMessage
+    def companion: GeneratedMessageCompanion[SpecificModel]
+    implicit def reader: Reader[SpecificModel, DetachedModel]
+
+    final def versioned[V](version: V)(modelReader: VersionedModelReader[V, DetachedModel]): (V, modelReader.VersionReader) =
+      version -> modelReader.readerMapping(companion)
+  }
+
+  object CompanionReader {
+    implicit def fromCompanion[P <: GeneratedMessage, M](gmc: GeneratedMessageCompanion[P])(
+        implicit rpm: Reader[P, M]
+    ): CompanionReader[M] = new CompanionReader[M] {
+      type SpecificModel = P
+      def companion: GeneratedMessageCompanion[P] = gmc
+      def reader: Reader[P, M]                    = rpm
+    }
+  }
 }
diff --git a/src/main/scala/io/moia/protos/teleproto/VersionedModelWriter.scala b/src/main/scala/io/moia/protos/teleproto/VersionedModelWriter.scala
@@ -37,16 +37,13 @@ import scala.util.{Failure, Success, Try}
   * Usage Example:
   *
   * {{{
-  * implicit val someModelWriter: ModelWriter[SomeDetachedModel] =
-  *    new ModelWriter[MyVersion, SomeDetachedModel] {
-  *      val writerMappings: WriterMappings =
-  *        ListMap(
-  *          VN -> writerMapping(vN.SomeApiModel),
-  *          ...
-  *          V2 -> writerMapping(v2.SomeApiModel),
-  *          V1 -> writerMapping(v1.SomeApiModel)
-  *        )
-  *    }
+  * implicit val someModelWriter: VersionedModelWriter[SomeDetachedModel] =
+  *   VersionedModelWriter[MyVersion, SomeDetachedModel](
+  *     VN -> vN.SomeApiModel,
+  *     ...
+  *     V2 -> v2.SomeApiModel,
+  *     V1 -> v1.SomeApiModel
+  *   )
   * }}}
   */
 trait VersionedModelWriter[Version, DetachedModel] {
@@ -120,6 +117,31 @@ trait VersionedModelWriter[Version, DetachedModel] {
 }
 
 object VersionedModelWriter {
-
   private val printer = new Printer().includingDefaultValueFields.formattingLongAsNumber
+
+  def apply[Version, DetachedModel](
+      writers: (Version, CompanionWriter[DetachedModel])*
+  ): VersionedModelWriter[Version, DetachedModel] = new VersionedModelWriter[Version, DetachedModel] {
+    val writerMappings: WriterMappings = ListMap(writers.map { case (v, w) => w.versioned(v) }: _*)
+  }
+
+  sealed trait CompanionWriter[DetachedModel] {
+    type SpecificModel <: GeneratedMessage
+    def writer: Writer[DetachedModel, SpecificModel]
+
+    final def versioned[V](version: V): (V, Writer[DetachedModel, GeneratedMessage]) =
+      version -> writer
+  }
+
+  object CompanionWriter {
+    implicit def fromCompanion[P <: GeneratedMessage, M](gmc: GeneratedMessageCompanion[P])(
+        implicit wmp: Writer[M, P]
+    ): CompanionWriter[M] = {
+      val _ = gmc
+      new CompanionWriter[M] {
+        type SpecificModel = P
+        def writer: Writer[M, P] = wmp
+      }
+    }
+  }
 }
diff --git a/src/test/scala/io/moia/protos/teleproto/ProtocolBuffersRoundTripTest.scala b/src/test/scala/io/moia/protos/teleproto/ProtocolBuffersRoundTripTest.scala
@@ -4,11 +4,17 @@ import io.moia.food.food
 import org.scalacheck.Gen
 import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
 
+import scala.util.Success
+
 class ProtocolBuffersRoundTripTest extends UnitTest with ScalaCheckPropertyChecks {
   import ProtocolBuffersRoundTripTest._
 
-  val mealReader: Reader[food.Meal, Meal] = ProtocolBuffers.reader[food.Meal, Meal]
-  val mealWriter: Writer[Meal, food.Meal] = ProtocolBuffers.writer[Meal, food.Meal]
+  implicit val reader: Reader[food.Meal, Meal] = ProtocolBuffers.reader[food.Meal, Meal]
+  implicit val writer: Writer[Meal, food.Meal] = ProtocolBuffers.writer[Meal, food.Meal]
+
+  val version     = 1
+  val modelReader = VersionedModelReader[Int, Meal](version -> food.Meal)
+  val modelWriter = VersionedModelWriter[Int, Meal](version -> food.Meal)
 
   val colorGen: Gen[Color] =
     Gen.oneOf(Color.Red, Color.Orange, Color.Yellow, Color.Pink, Color.Blue)
@@ -37,7 +43,19 @@ class ProtocolBuffersRoundTripTest extends UnitTest with ScalaCheckPropertyCheck
   "ProtocolBuffers" should {
     "generate writer and reader that round trip successfully" in {
       forAll(mealGen) { meal =>
-        mealReader.read(mealWriter.write(meal)) shouldBe PbSuccess(meal)
+        reader.read(writer.write(meal)) shouldBe PbSuccess(meal)
+      }
+    }
+
+    "create model writer and reader that round trip successfully via JSON" in {
+      forAll(mealGen) { meal =>
+        modelWriter.toJson(meal, version).flatMap(modelReader.fromJson(_, version)) shouldBe Success(PbSuccess(meal))
+      }
+    }
+
+    "create model writer and reader that round trip successfully via Protocol Buffers" in {
+      forAll(mealGen) { meal =>
+        modelWriter.toByteArray(meal, version).flatMap(modelReader.fromProto(_, version)) shouldBe Success(PbSuccess(meal))
       }
     }
   }