[gen] fix for codegen of sumtypes with reusable fields

build.sbt

@@ -293,6 +293,7 @@ lazy val zioHttpGen = (project in file("zio-http-gen"))
       `zio-test-sbt`,
       scalafmt.cross(CrossVersion.for3Use2_13),
       scalametaParsers.cross(CrossVersion.for3Use2_13).exclude("org.scala-lang.modules", "scala-collection-compat_2.13"),
+      `zio-json-yaml` % Test
     ),
   )
   .settings(

project/Dependencies.scala

@@ -7,6 +7,7 @@ object Dependencies {
   val ScalaCompactCollectionVersion = "2.12.0"
   val ZioVersion                    = "2.1.1"
   val ZioCliVersion                 = "0.5.0"
+  val ZioJsonVersion                = "0.6.2"
   val ZioSchemaVersion              = "1.1.1"
   val SttpVersion                   = "3.3.18"
   val ZioConfigVersion              = "4.0.2"
@@ -34,6 +35,7 @@ object Dependencies {
 
   val zio                   = "dev.zio" %% "zio"                 % ZioVersion
   val `zio-cli`             = "dev.zio" %% "zio-cli"             % ZioCliVersion
+  val `zio-json-yaml`       = "dev.zio" %% "zio-json-yaml"       % ZioJsonVersion
   val `zio-streams`         = "dev.zio" %% "zio-streams"         % ZioVersion
   val `zio-schema`          = "dev.zio" %% "zio-schema"          % ZioSchemaVersion
   val `zio-schema-json`     = "dev.zio" %% "zio-schema-json"     % ZioSchemaVersion

zio-http-gen/src/main/scala/zio/http/gen/openapi/Config.scala

@@ -0,0 +1,15 @@
+package zio.http.gen.openapi
+
+final case class Config(commonFieldsOnSuperType: Boolean)
+object Config {
+
+  val default: Config = Config(
+    commonFieldsOnSuperType = false,
+  )
+
+  lazy val config: zio.Config[Config] =
+    zio.Config
+      .boolean("common-fields-on-super-type")
+      .withDefault(Config.default.commonFieldsOnSuperType)
+      .map(Config.apply)
+}

zio-http-gen/src/main/scala/zio/http/gen/scala/Code.scala

@@ -62,10 +62,11 @@ object Code {
       Object(name, schema = false, endpoints, Nil, Nil, Nil)
   }
 
-  final case class CaseClass(name: String, fields: List[Field], companionObject: Option[Object]) extends ScalaType
+  final case class CaseClass(name: String, fields: List[Field], companionObject: Option[Object], mixins: List[String])
+      extends ScalaType
 
   object CaseClass {
-    def apply(name: String): CaseClass = CaseClass(name, Nil, None)
+    def apply(name: String, mixins: List[String]): CaseClass = CaseClass(name, Nil, None, mixins)
   }
 
   final case class Enum(
@@ -75,6 +76,7 @@ object Code {
     discriminator: Option[String] = None,
     noDiscriminator: Boolean = false,
     schema: Boolean = true,
+    abstractMembers: List[Field] = Nil,
   ) extends ScalaType
 
   sealed abstract case class Field private (name: String, fieldType: ScalaType) extends Code {

zio-http-gen/src/main/scala/zio/http/gen/scala/CodeGen.scala

@@ -86,20 +86,24 @@ object CodeGen {
           "\n}"
       Nil -> content
 
-    case Code.CaseClass(name, fields, companionObject) =>
+    case Code.CaseClass(name, fields, companionObject, mixins) =>
       val (imports, contents)    = fields.map(render(basePackage)).unzip
       val (coImports, coContent) =
         companionObject.map { co =>
           val (coImports, coContent) = render(basePackage)(co)
           (coImports, s"\n$coContent")
         }.getOrElse(Nil -> "")
+      val mixinsString           = mixins match {
+        case Nil => ""
+        case _   => mixins.mkString(" extends ", " with ", "")
+      }
       val content                =
         s"case class $name(\n" +
           contents.mkString(",\n").replace("val ", " ") +
-          "\n)" + coContent
+          "\n)" + mixinsString + coContent
       (imports.flatten ++ coImports).distinct -> content
 
-    case Code.Enum(name, cases, caseNames, discriminator, noDiscriminator, schema) =>
+    case Code.Enum(name, cases, caseNames, discriminator, noDiscriminator, schema, abstractMembers) =>
       val discriminatorAnnotation      =
         if (noDiscriminator) "@noDiscriminator\n" else ""
       val discriminatorNameAnnotation  =
@@ -118,15 +122,40 @@ object CodeGen {
           imports -> contents.mkString("\n")
         }
 
+      val (traitBodyImports, traitBody) = {
+        val traitBodyBuilder = new StringBuilder().append(' ')
+        var pre              = '{'
+        val imports          = abstractMembers.foldLeft(List.empty[Code.Import]) {
+          case (importsAcc, Code.Field(name, fieldType)) =>
+            val (imports, tpe) = render(basePackage)(fieldType)
+            if (tpe.isEmpty) importsAcc
+            else {
+              traitBodyBuilder += pre
+              pre = '\n'
+              traitBodyBuilder ++= "def "
+              traitBodyBuilder ++= name
+              traitBodyBuilder ++= ": "
+              traitBodyBuilder ++= tpe
+
+              imports ::: importsAcc
+            }
+        }
+        val body             =
+          if (pre == '{') "\n"
+          else traitBodyBuilder.append("\n}\n").result()
+
+        imports -> body
+      }
+
       val content =
         discriminatorAnnotation +
           discriminatorNameAnnotation +
-          s"sealed trait $name\n" +
+          s"sealed trait $name" + traitBody +
           s"object $name {\n" +
           (if (schema) s"\n\n implicit val codec: Schema[$name] = DeriveSchema.gen[$name]\n" else "") +
           casesContent +
           "\n}"
-      casesImports.flatten.distinct -> content
+      casesImports.foldRight(traitBodyImports)(_ ::: _).distinct -> content
 
     case col: Code.Collection =>
       col match {

zio-http-gen/src/test/resources/ComponentAnimal.scala

@@ -0,0 +1,31 @@
+package test.component
+
+import zio.schema._
+import zio.schema.annotation._
+
+@noDiscriminator
+sealed trait Animal
+object Animal {
+
+  implicit val codec: Schema[Animal] = DeriveSchema.gen[Animal]
+  case class Alligator(
+    age: Int,
+    weight: Float,
+    num_teeth: Int,
+  ) extends Animal
+  object Alligator {
+
+    implicit val codec: Schema[Alligator] = DeriveSchema.gen[Alligator]
+
+  }
+  case class Zebra(
+    age: Int,
+    weight: Float,
+    num_stripes: Int,
+  ) extends Animal
+  object Zebra {
+
+    implicit val codec: Schema[Zebra] = DeriveSchema.gen[Zebra]
+
+  }
+}

zio-http-gen/src/test/resources/ComponentAnimalWithAbstractMembers.scala

@@ -0,0 +1,34 @@
+package test.component
+
+import zio.schema._
+import zio.schema.annotation._
+
+@noDiscriminator
+sealed trait Animal {
+  def age: Int
+  def weight: Float
+}
+object Animal       {
+
+  implicit val codec: Schema[Animal] = DeriveSchema.gen[Animal]
+  case class Alligator(
+    age: Int,
+    weight: Float,
+    num_teeth: Int,
+  ) extends Animal
+  object Alligator {
+
+    implicit val codec: Schema[Alligator] = DeriveSchema.gen[Alligator]
+
+  }
+  case class Zebra(
+    age: Int,
+    weight: Float,
+    num_stripes: Int,
+  ) extends Animal
+  object Zebra {
+
+    implicit val codec: Schema[Zebra] = DeriveSchema.gen[Zebra]
+
+  }
+}

zio-http-gen/src/test/resources/ComponentHttpError.scala

@@ -0,0 +1,12 @@
+package test.component
+
+import zio.schema._
+
+case class HttpError(
+  messages: Option[String],
+)
+object HttpError {
+
+  implicit val codec: Schema[HttpError] = DeriveSchema.gen[HttpError]
+
+}

zio-http-gen/src/test/resources/EndpointForZoo.scala

@@ -0,0 +1,15 @@
+package test.api.v1.zoo
+
+import test.component._
+import zio.Chunk
+
+object Animal {
+  import zio.http._
+  import zio.http.endpoint._
+  import zio.http.codec._
+  val get_animal = Endpoint(Method.GET / "api" / "v1" / "zoo" / string("animal"))
+    .in[Unit]
+    .out[Chunk[Animal]](status = Status.Ok)
+    .outError[HttpError](status = Status.InternalServerError)
+
+}

zio-http-gen/src/test/resources/EndpointForZooNoError.scala

@@ -0,0 +1,14 @@
+package test.api.v1.zoo
+
+import test.component._
+import zio.Chunk
+
+object Animal {
+  import zio.http._
+  import zio.http.endpoint._
+  import zio.http.codec._
+  val get_animal = Endpoint(Method.GET / "api" / "v1" / "zoo" / string("animal"))
+    .in[Unit]
+    .out[Chunk[Animal]](status = Status.Ok)
+
+}

zio-http-gen/src/test/resources/GeneratedPaymentNamedDiscriminator.scala

@@ -12,7 +12,7 @@ object PaymentNamedDiscriminator {
   case class Card(
     number: String,
     cvv: String,
-  )
+  ) extends PaymentNamedDiscriminator
   object Card {
 
     implicit val codec: Schema[Card] = DeriveSchema.gen[Card]
@@ -21,7 +21,7 @@ object PaymentNamedDiscriminator {
   @caseName("cash")
   case class Cash(
     amount: Int,
-  )
+  ) extends PaymentNamedDiscriminator
   object Cash {
 
     implicit val codec: Schema[Cash] = DeriveSchema.gen[Cash]

zio-http-gen/src/test/resources/GeneratedPaymentNoDiscriminator.scala

@@ -11,15 +11,15 @@ object PaymentNoDiscriminator {
   case class Card(
     number: String,
     cvv: String,
-  )
+  ) extends PaymentNoDiscriminator
   object Card {
 
     implicit val codec: Schema[Card] = DeriveSchema.gen[Card]
 
   }
   case class Cash(
     amount: Int,
-  )
+  ) extends PaymentNoDiscriminator
   object Cash {
 
     implicit val codec: Schema[Cash] = DeriveSchema.gen[Cash]

zio-http-gen/src/test/resources/inline_schema_sumtype_with_multiple_contradicting_reusable_fields.yaml

@@ -0,0 +1,80 @@
+info:
+  title: Animals Service
+  version: 0.0.1
+tags:
+  - name: Animals_API
+paths:
+  /api/v1/zoo/{animal}:
+    get:
+      operationId: get_animal
+      parameters:
+        - in: path
+          name: animal
+          schema:
+            type: string
+          required: true
+      tags:
+        - Animals_API
+      description: Get animals by species name
+      responses:
+        "200":
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Animal'
+          description: OK
+openapi: 3.0.3
+components:
+  schemas:
+    Animal:
+      oneOf:
+        - $ref: '#/components/schemas/Alligator'
+        - $ref: '#/components/schemas/Zebra'
+    HasAgeAndWeight:
+      type: object
+      required:
+        - age
+      properties:
+        age:
+          type: integer
+          format: int32
+          minimum: 0
+        weight:
+          type: number
+          format: float
+          minimum: 0
+    HasWeight:
+      type: object
+      required:
+        - weight
+      properties:
+        weight:
+          type: number
+          format: double
+          minimum: 0
+    Alligator:
+      allOf:
+        - $ref: '#/components/schemas/HasAgeAndWeight'
+        - $ref: '#/components/schemas/HasWeight'
+        - type: object
+          required:
+            - num_teeth
+          properties:
+            num_teeth:
+              type: integer
+              format: int32
+              minimum: 0
+    Zebra:
+      allOf:
+        - $ref: '#/components/schemas/HasAgeAndWeight'
+        - $ref: '#/components/schemas/HasWeight'
+        - type: object
+          required:
+            - num_stripes
+          properties:
+            num_stripes:
+              type: integer
+              format: int32
+              minimum: 0