codegen: implement oneOf support (#3624)

softwaremill · Apr 3, 2024 · 0196f34 · 0196f34
1 parent ff60ba6
commit 0196f34
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diff --git a/doc/generator/sbt-openapi-codegen.md b/doc/generator/sbt-openapi-codegen.md
@@ -35,15 +35,16 @@ defined case-classes and endpoint definitions.
 The generator currently supports these settings, you can override them in the `build.sbt`;
 
 ```eval_rst
-=============================== ==================================== =====================================================================
-setting                         default value                        description
-=============================== ==================================== =====================================================================
-openapiSwaggerFile              baseDirectory.value / "swagger.yaml" The swagger file with the api definitions.
-openapiPackage                  sttp.tapir.generated                 The name for the generated package.
-openapiObject                   TapirGeneratedEndpoints              The name for the generated object.
-openapiUseHeadTagForObjectName  false                                If true, put endpoints in separate files based on first declared tag.
-openapiJsonSerdeLib             circe                                The json serde library to use.
-=============================== ==================================== =====================================================================
+===================================== ==================================== =======================================================================================
+setting                               default value                        description
+===================================== ==================================== =======================================================================================
+openapiSwaggerFile                    baseDirectory.value / "swagger.yaml" The swagger file with the api definitions.
+openapiPackage                        sttp.tapir.generated                 The name for the generated package.
+openapiObject                         TapirGeneratedEndpoints              The name for the generated object.
+openapiUseHeadTagForObjectName        false                                If true, put endpoints in separate files based on first declared tag.
+openapiJsonSerdeLib                   circe                                The json serde library to use.
+openapiValidateNonDiscriminatedOneOfs true                                 Whether to fail if variants of a oneOf without a discriminator cannot be disambiguated.
+===================================== ==================================== =======================================================================================
 ```
 
 The general usage is;
@@ -114,7 +115,7 @@ representation types for the binary data
 We currently miss a lot of OpenApi features like:
 
 - tags
-- ADTs
+- anyOf/allOf
 - missing model types and meta descriptions (like date, minLength)
 - file handling
 
diff --git a/openapi-codegen/cli/src/main/scala/sttp/tapir/codegen/GenScala.scala b/openapi-codegen/cli/src/main/scala/sttp/tapir/codegen/GenScala.scala
@@ -46,6 +46,15 @@ object GenScala {
   private val headTagForNamesOpt: Opts[Boolean] =
     Opts.flag("headTagForNames", "Whether to group generated endpoints by first declared tag", "t").orFalse
 
+  private val validateNonDiscriminatedOneOfsOpt: Opts[Boolean] =
+    Opts
+      .flag(
+        "validateNonDiscriminatedOneOfs",
+        "Whether to validate that all variants of oneOfs without discriminators can be disambiguated",
+        "v"
+      )
+      .orFalse
+
   private val jsonLibOpt: Opts[Option[String]] =
     Opts.option[String]("jsonLib", "Json library to use for serdes", "j").orNone
 
@@ -62,13 +71,21 @@ object GenScala {
       }
 
   val cmd: Command[IO[ExitCode]] = Command("genscala", "Generate Scala classes", helpFlag = true) {
-    (fileOpt, packageNameOpt, destDirOpt, objectNameOpt, targetScala3Opt, headTagForNamesOpt, jsonLibOpt).mapN {
-      case (file, packageName, destDir, maybeObjectName, targetScala3, headTagForNames, jsonLib) =>
+    (fileOpt, packageNameOpt, destDirOpt, objectNameOpt, targetScala3Opt, headTagForNamesOpt, jsonLibOpt, validateNonDiscriminatedOneOfsOpt)
+      .mapN { case (file, packageName, destDir, maybeObjectName, targetScala3, headTagForNames, jsonLib, validateNonDiscriminatedOneOfs) =>
         val objectName = maybeObjectName.getOrElse(DefaultObjectName)
 
         def generateCode(doc: OpenapiDocument): IO[Unit] = for {
           contents <- IO.pure(
-            BasicGenerator.generateObjects(doc, packageName, objectName, targetScala3, headTagForNames, jsonLib.getOrElse("circe"))
+            BasicGenerator.generateObjects(
+              doc,
+              packageName,
+              objectName,
+              targetScala3,
+              headTagForNames,
+              jsonLib.getOrElse("circe"),
+              validateNonDiscriminatedOneOfs
+            )
           )
           destFiles <- contents.toVector.traverse { case (fileName, content) => writeGeneratedFile(destDir, fileName, content) }
           _ <- IO.println(s"Generated endpoints written to: ${destFiles.mkString(", ")}")
@@ -81,7 +98,7 @@ object GenScala {
             case Right(doc) => generateCode(doc).as(ExitCode.Success)
           }
         } yield exitCode
-    }
+      }
   }
 
   private def readFile(file: File): IO[String] = {

diff --git a/openapi-codegen/core/src/main/scala/sttp/tapir/codegen/BasicGenerator.scala b/openapi-codegen/core/src/main/scala/sttp/tapir/codegen/BasicGenerator.scala
@@ -33,7 +33,8 @@ object BasicGenerator {
       objName: String,
       targetScala3: Boolean,
       useHeadTagForObjectNames: Boolean,
-      jsonSerdeLib: String
+      jsonSerdeLib: String,
+      validateNonDiscriminatedOneOfs: Boolean
   ): Map[String, String] = {
     val normalisedJsonLib = jsonSerdeLib.toLowerCase match {
       case "circe"    => JsonSerdeLib.Circe
@@ -46,12 +47,30 @@ object BasicGenerator {
     }
 
     val EndpointDefs(endpointsByTag, queryParamRefs, jsonParamRefs) = endpointGenerator.endpointDefs(doc, useHeadTagForObjectNames)
+    val GeneratedClassDefinitions(classDefns, extras) =
+      classGenerator
+        .classDefs(
+          doc = doc,
+          targetScala3 = targetScala3,
+          queryParamRefs = queryParamRefs,
+          jsonSerdeLib = normalisedJsonLib,
+          jsonParamRefs = jsonParamRefs,
+          fullModelPath = s"$packagePath.$objName",
+          validateNonDiscriminatedOneOfs = validateNonDiscriminatedOneOfs
+        )
+        .getOrElse(GeneratedClassDefinitions("", None))
+    val isSplit = extras.nonEmpty
+    val internalImports =
+      if (isSplit)
+        s"""import $packagePath.$objName._
+         |import ${objName}JsonSerdes._""".stripMargin
+      else s"import $objName._"
     val taggedObjs = endpointsByTag.collect {
       case (Some(headTag), body) if body.nonEmpty =>
         val taggedObj =
           s"""package $packagePath
            |
-           |import $objName._
+           |$internalImports
            |
            |object $headTag {
            |
@@ -62,6 +81,15 @@ object BasicGenerator {
            |}""".stripMargin
         headTag -> taggedObj
     }
+    val extraObj = extras.map { body =>
+      s"""package $packagePath
+         |
+         |object ${objName}JsonSerdes {
+         |  import $packagePath.$objName._
+         |${indent(2)(body)}
+         |}""".stripMargin
+    }
+    val endpointsInMain = endpointsByTag.getOrElse(None, "")
 
     val maybeSpecificationExtensionKeys = doc.paths
       .flatMap { p =>
@@ -80,21 +108,23 @@ object BasicGenerator {
       }
       .mkString("\n")
 
+    val serdeImport = if (isSplit && endpointsInMain.nonEmpty) s"\nimport $packagePath.${objName}JsonSerdes._" else ""
     val mainObj = s"""|
         |package $packagePath
         |
         |object $objName {
         |
-        |${indent(2)(imports(normalisedJsonLib))}
+        |${indent(2)(imports(normalisedJsonLib) + serdeImport)}
         |
-        |${indent(2)(classGenerator.classDefs(doc, targetScala3, queryParamRefs, normalisedJsonLib, jsonParamRefs).getOrElse(""))}
+        |${indent(2)(classDefns)}
         |
         |${indent(2)(maybeSpecificationExtensionKeys)}
         |
-        |${indent(2)(endpointsByTag.getOrElse(None, ""))}
+        |${indent(2)(endpointsInMain)}
+        |
         |}
         |""".stripMargin
-    taggedObjs + (objName -> mainObj)
+    taggedObjs ++ extraObj.map(s"${objName}JsonSerdes" -> _) + (objName -> mainObj)
   }
 
   private[codegen] def imports(jsonSerdeLib: JsonSerdeLib.JsonSerdeLib): String = {