Fix enum serdes generated from codegen (#3085)

softwaremill · Aug 10, 2023 · e5bd96c · e5bd96c
1 parent 05f9b2b
commit e5bd96c
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Showing 6 changed files with 21 additions and 14 deletions.
diff --git a/build.sbt b/build.sbt
@@ -1927,7 +1927,8 @@ lazy val openapiCodegenCore: ProjectMatrix = (projectMatrix in file("openapi-cod
       "com.47deg" %% "scalacheck-toolbox-datetime" % "0.7.0" % Test,
       scalaOrganization.value % "scala-reflect" % scalaVersion.value,
       scalaOrganization.value % "scala-compiler" % scalaVersion.value % Test,
-      "com.beachape" %% "enumeratum" % "1.7.3" % Test
+      "com.beachape" %% "enumeratum" % "1.7.3" % Test,
+      "com.beachape" %% "enumeratum-circe" % "1.7.3" % Test
     )
   )
   .dependsOn(core % Test, circeJson % Test)

diff --git a/doc/generator/sbt-openapi-codegen.md b/doc/generator/sbt-openapi-codegen.md
@@ -58,7 +58,9 @@ val docs = TapirGeneratedEndpoints.generatedEndpoints.toOpenAPI("My Bookshop", "
 
 Currently, the generated code depends on `"io.circe" %% "circe-generic"`. In the future probably we will make the encoder/decoder json lib configurable (PRs welcome).
 
-String-like enums depend on `"com.beachape" %% "enumeratum"`. Other forms of OpenApi enum are not currently supported. 
+String-like enums in Scala 2 depend on both `"com.beachape" %% "enumeratum"` and `"com.beachape" %% "enumeratum-circe"`.
+For Scala 3 we derive native enums, and depend instead on `"org.latestbit" %% "circe-tagged-adt-codec"`.
+Other forms of OpenApi enum are not currently supported.
 
 We currently miss a lot of OpenApi features like:
  - tags

diff --git a/openapi-codegen/core/src/main/scala/sttp/tapir/codegen/ClassDefinitionGenerator.scala b/openapi-codegen/core/src/main/scala/sttp/tapir/codegen/ClassDefinitionGenerator.scala
@@ -37,13 +37,13 @@ class ClassDefinitionGenerator {
 
   // Uses enumeratum for scala 2, but generates scala 3 enums instead where it can
   private[codegen] def generateEnum(name: String, obj: OpenapiSchemaEnum, targetScala3: Boolean): Seq[String] = if (targetScala3) {
-    s"""enum $name {
+    s"""enum $name derives org.latestbit.circe.adt.codec.JsonTaggedAdt.PureCodec {
        |  case ${obj.items.map(_.value).mkString(", ")}
        |}""".stripMargin :: Nil
   } else {
     val members = obj.items.map { i => s"case object ${i.value} extends $name" }
     s"""|sealed trait $name extends EnumEntry
-        |object $name extends Enum[$name] {
+        |object $name extends Enum[$name] with CirceEnum[$name] {
         |  val values = findValues
         |${indent(2)(members.mkString("\n"))}
         |}""".stripMargin :: Nil

diff --git a/...api-codegen/core/src/main/scala/sttp/tapir/codegen/openapi/models/OpenapiSchemaType.scala b/...api-codegen/core/src/main/scala/sttp/tapir/codegen/openapi/models/OpenapiSchemaType.scala
@@ -89,8 +89,9 @@ object OpenapiSchemaType {
     val nullable = false
   }
 
-  // Can't support non-string enum types although that should apparently be legal (see https://json-schema.org/draft/2020-12/json-schema-validation.html#enum)
+  // Can't currently support non-string enum types although that should apparently be legal (see https://json-schema.org/draft/2020-12/json-schema-validation.html#enum)
   case class OpenapiSchemaEnum(
+      `type`: String,
       items: Seq[OpenapiSchemaConstantString],
       nullable: Boolean
   ) extends OpenapiSchemaType
@@ -241,9 +242,11 @@ object OpenapiSchemaType {
 
   implicit val OpenapiSchemaEnumDecoder: Decoder[OpenapiSchemaEnum] = { (c: HCursor) =>
     for {
+      tpe <- c.downField("type").as[String]
+      _ <- Either.cond(tpe == "string", (), DecodingFailure("only string enums are supported", c.history))
       items <- c.downField("enum").as[Seq[OpenapiSchemaConstantString]]
       nb <- c.downField("nullable").as[Option[Boolean]]
-    } yield OpenapiSchemaEnum(items, nb.getOrElse(false))
+    } yield OpenapiSchemaEnum(tpe, items, nb.getOrElse(false))
   }
 
   implicit val OpenapiSchemaObjectDecoder: Decoder[OpenapiSchemaObject] = { (c: HCursor) =>
@@ -282,12 +285,12 @@ object OpenapiSchemaType {
 
   implicit lazy val OpenapiSchemaTypeDecoder: Decoder[OpenapiSchemaType] =
     List[Decoder[OpenapiSchemaType]](
+      Decoder[OpenapiSchemaEnum].widen,
       Decoder[OpenapiSchemaSimpleType].widen,
       Decoder[OpenapiSchemaMixedType].widen,
       Decoder[OpenapiSchemaNot].widen,
       Decoder[OpenapiSchemaObject].widen,
       Decoder[OpenapiSchemaMap].widen,
-      Decoder[OpenapiSchemaArray].widen,
-      Decoder[OpenapiSchemaEnum].widen
+      Decoder[OpenapiSchemaArray].widen
     ).reduceLeft(_ or _)
 }
diff --git a/openapi-codegen/core/src/test/scala/sttp/tapir/codegen/ClassDefinitionGeneratorSpec.scala b/openapi-codegen/core/src/test/scala/sttp/tapir/codegen/ClassDefinitionGeneratorSpec.scala
@@ -44,7 +44,7 @@ class ClassDefinitionGeneratorSpec extends CompileCheckTestBase {
       Some(
         OpenapiComponent(
           Map(
-            "Test" -> OpenapiSchemaEnum(Seq(OpenapiSchemaConstantString("paperback"), OpenapiSchemaConstantString("hardback")), false)
+            "Test" -> OpenapiSchemaEnum("string", Seq(OpenapiSchemaConstantString("paperback"), OpenapiSchemaConstantString("hardback")), false)
           )
         )
       )
@@ -250,7 +250,7 @@ class ClassDefinitionGeneratorSpec extends CompileCheckTestBase {
       Some(
         OpenapiComponent(
           Map(
-            "Test" -> OpenapiSchemaEnum(Seq(OpenapiSchemaConstantString("enum1"), OpenapiSchemaConstantString("enum2")), false)
+            "Test" -> OpenapiSchemaEnum("string", Seq(OpenapiSchemaConstantString("enum1"), OpenapiSchemaConstantString("enum2")), false)
           )
         )
       )
@@ -259,7 +259,8 @@ class ClassDefinitionGeneratorSpec extends CompileCheckTestBase {
     val gen = new ClassDefinitionGenerator()
     val res = gen.classDefs(doc, true)
     // can't just check whether this compiles, because our tests only run on scala 2.12 - so instead just eyeball it...
-    res shouldBe Some("""enum Test {
+    res shouldBe Some(
+      """enum Test derives org.latestbit.circe.adt.codec.JsonTaggedAdt.PureCodec {
         |  case enum1, enum2
         |}""".stripMargin)
   }
@@ -273,7 +274,7 @@ class ClassDefinitionGeneratorSpec extends CompileCheckTestBase {
         OpenapiComponent(
           Map(
             "MyObject" -> OpenapiSchemaObject(Map("text" -> OpenapiSchemaString(true)), Seq("text"), false),
-            "MyEnum" -> OpenapiSchemaEnum(Seq(OpenapiSchemaConstantString("enum1"), OpenapiSchemaConstantString("enum2")), false),
+            "MyEnum" -> OpenapiSchemaEnum("string", Seq(OpenapiSchemaConstantString("enum1"), OpenapiSchemaConstantString("enum2")), false),
             "MyMapPrimitive" -> OpenapiSchemaMap(OpenapiSchemaString(false), false),
             "MyMapObject" -> OpenapiSchemaMap(OpenapiSchemaRef("#/components/schemas/MyObject"), false),
             "MyMapEnum" -> OpenapiSchemaMap(OpenapiSchemaRef("#/components/schemas/MyEnum"), false)

diff --git a/openapi-codegen/core/src/test/scala/sttp/tapir/codegen/models/ModelParserSpec.scala b/openapi-codegen/core/src/test/scala/sttp/tapir/codegen/models/ModelParserSpec.scala
@@ -153,7 +153,7 @@ class ModelParserSpec extends AnyFlatSpec with Matchers with Checkers {
 
   it should "parse enums" in {
     val yaml =
-      """
+      """type: string
         |enum:
         |- paperback
         |- hardback""".stripMargin
@@ -164,7 +164,7 @@ class ModelParserSpec extends AnyFlatSpec with Matchers with Checkers {
       .flatMap(_.as[OpenapiSchemaType])
 
     res shouldBe Right(
-      OpenapiSchemaEnum(Seq(OpenapiSchemaConstantString("paperback"), OpenapiSchemaConstantString("hardback")), false)
+      OpenapiSchemaEnum("string", Seq(OpenapiSchemaConstantString("paperback"), OpenapiSchemaConstantString("hardback")), false)
     )
   }
 }