Add support for oneOf with discriminator when using kotlinx.serialization (#22373)

* Generate wrappers for oneOf with discriminator when using kotlinx.serialization * Add spec with oneOf using discriminator * Add config to generate samples * Generate samples * Update samples * Change naming of wrapper classes * Fix empty model test * Update GH workflow with new samples
2026-04-22 21:39:11 +00:00 · 2025-11-18 20:55:37 +02:00
parent c52cc1f275
commit e86daf9059
51 changed files with 1949 additions and 19 deletions
--- a/.github/workflows/samples-kotlin-client.yaml
+++ b/.github/workflows/samples-kotlin-client.yaml
@@ -72,6 +72,7 @@ jobs:
          - samples/client/others/kotlin-jvm-okhttp-path-comments
          - samples/client/others/kotlin-integer-enum
          - samples/client/petstore/kotlin-allOf-discriminator-kotlinx-serialization
+          - samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization
    steps:
      - uses: actions/checkout@v5
      - uses: actions/setup-java@v5
--- a/bin/configs/kotlin-oneOf-discriminator-kotlinx-serialization.yaml
+++ b/bin/configs/kotlin-oneOf-discriminator-kotlinx-serialization.yaml
@@ -0,0 +1,12 @@
+generatorName: kotlin
+outputDir: samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization
+inputSpec: modules/openapi-generator/src/test/resources/3_0/kotlin/polymorphism-oneof-discriminator.yaml
+templateDir: modules/openapi-generator/src/main/resources/kotlin-client
+additionalProperties:
+  artifactId: kotlin-oneOf-discriminator
+  serializableModel: "false"
+  dateLibrary: java8
+  library: jvm-retrofit2
+  enumUnknownDefaultCase: true
+  serializationLibrary: kotlinx_serialization
+  generateOneOfAnyOfWrappers: true
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java
@@ -20,6 +20,7 @@ package org.openapitools.codegen.languages;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.google.common.collect.ImmutableMap;
 import com.samskivert.mustache.Mustache;
+import com.samskivert.mustache.Template;
 import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.media.StringSchema;
 import lombok.Getter;
@@ -35,6 +36,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.io.File;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
 import java.util.*;
 import java.util.function.Function;
 import java.util.regex.Pattern;
@@ -1172,4 +1176,15 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
            }
        }
    }
+
+    protected static abstract class CustomLambda implements Mustache.Lambda {
+        @Override
+        public void execute(Template.Fragment frag, Writer out) throws IOException {
+            final StringWriter tempWriter = new StringWriter();
+            frag.execute(tempWriter);
+            out.write(formatFragment(tempWriter.toString()));
+        }
+
+        public abstract String formatFragment(String fragment);
+    }
 }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java
@@ -22,7 +22,6 @@ import lombok.Getter;
 import lombok.Setter;
 import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.*;
-import org.openapitools.codegen.meta.features.*;
 import org.openapitools.codegen.model.ModelMap;
 import org.openapitools.codegen.model.ModelsMap;
 import org.openapitools.codegen.model.OperationMap;
@@ -40,10 +39,8 @@ import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;

-import com.samskivert.mustache.Mustache;
 import lombok.Getter;
 import lombok.Setter;
-import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.CliOption;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.CodegenModel;
@@ -60,14 +57,7 @@ import org.openapitools.codegen.meta.features.ParameterFeature;
 import org.openapitools.codegen.meta.features.SchemaSupportFeature;
 import org.openapitools.codegen.meta.features.SecurityFeature;
 import org.openapitools.codegen.meta.features.WireFormatFeature;
-import org.openapitools.codegen.model.ModelMap;
-import org.openapitools.codegen.model.ModelsMap;
-import org.openapitools.codegen.model.OperationMap;
-import org.openapitools.codegen.model.OperationsMap;
 import org.openapitools.codegen.templating.mustache.ReplaceAllLambda;
-import org.openapitools.codegen.utils.ProcessUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;

 import static java.util.Collections.sort;

@@ -569,6 +559,7 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
        // as the parser interrupts that as a start of a multiline comment.
        // We replace paths like `/v1/foo/*` with `/v1/foo/<*>` to avoid this
        additionalProperties.put("sanitizePathComment", new ReplaceAllLambda("\\/\\*", "/<*>"));
+        additionalProperties.put("fnToOneOfWrapperName", new ToOneOfWrapperName());
    }

    private void processDateLibrary() {
@@ -974,11 +965,21 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
                    if (discriminator == null) {
                        continue;
                    }
+
+                    // When using generateOneOfAnyOfWrappers and encountering oneOf, we keep discriminator properties,
+                    // because single entity can be referenced in multiple "parent" entities,
+                    // so discriminator for one might not be discriminator for another.
+                    boolean shouldKeepDiscriminatorField = generateOneOfAnyOfWrappers && cm.oneOf != null && !cm.oneOf.isEmpty();
+
+                    if (shouldKeepDiscriminatorField) {
+                        continue;
+                    }
+
                    // Remove discriminator property from the base class, it is not needed in the generated code
                    getAllVarProperties(cm).forEach(list -> list.removeIf(var -> var.name.equals(discriminator.getPropertyName())));

                    for (CodegenDiscriminator.MappedModel mappedModel : discriminator.getMappedModels()) {
-                        // Add the mapping name to additionalProperties.disciminatorValue
+                        // Add the mapping name to additionalProperties.discriminatorValue
                        // The mapping name is used to define SerializedName, which in result makes derived classes
                        // found by kotlinx-serialization during deserialization
                        CodegenProperty additionalProperties = mappedModel.getModel().getAdditionalProperties();
@@ -996,7 +997,6 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
                            mappedModel.getModel().setHasVars(false);
                        }
                    }
-
                }
            }
        }
@@ -1141,6 +1141,13 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
        param.defaultValue = type + "." + param.enumDefaultValue;
    }

+    private class ToOneOfWrapperName extends CustomLambda {
+        @Override
+        public String formatFragment(String fragment) {
+            return toModelName(StringUtils.lowerCase(fragment)) + "Wrapper";
+        }
+    }
+
    @Override
    public void postProcess() {
        System.out.println("################################################################################");
--- a/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache
@@ -37,6 +37,28 @@ import kotlinx.serialization.builtins.serializer
 import kotlinx.serialization.encoding.Decoder
 import kotlinx.serialization.encoding.Encoder
 {{/enumUnknownDefaultCase}}
+{{^enumUnknownDefaultCase}}
+{{#generateOneOfAnyOfWrappers}}
+{{#discriminator}}
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+{{/discriminator}}
+{{/generateOneOfAnyOfWrappers}}
+{{/enumUnknownDefaultCase}}
+{{#generateOneOfAnyOfWrappers}}
+{{#discriminator}}
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+{{/discriminator}}
+{{/generateOneOfAnyOfWrappers}}
 {{#hasEnums}}
 {{/hasEnums}}
 {{/kotlinx_serialization}}
@@ -57,7 +79,9 @@ import java.io.Serializable
 import {{roomModelPackage}}.{{classname}}RoomModel
 import {{packageName}}.infrastructure.ITransformForStorage
 {{/generateRoomModels}}
+{{^kotlinx_serialization}}
 import java.io.IOException
+{{/kotlinx_serialization}}

 /**
 * {{{description}}}
@@ -66,12 +90,68 @@ import java.io.IOException
 {{#parcelizeModels}}
@Parcelize
 {{/parcelizeModels}}
+{{^generateOneOfAnyOfWrappers}}
+{{^discriminator}}
 {{#multiplatform}}{{^discriminator}}@Serializable{{/discriminator}}{{/multiplatform}}{{#kotlinx_serialization}}{{#serializableModel}}@KSerializable{{/serializableModel}}{{^serializableModel}}@Serializable{{/serializableModel}}{{/kotlinx_serialization}}{{#moshi}}{{#moshiCodeGen}}@JsonClass(generateAdapter = true){{/moshiCodeGen}}{{/moshi}}{{#jackson}}{{#discriminator}}{{>typeInfoAnnotation}}{{/discriminator}}{{/jackson}}
+{{/discriminator}}
+{{/generateOneOfAnyOfWrappers}}
+{{#kotlinx_serialization}}
+{{#generateOneOfAnyOfWrappers}}
+{{#discriminator}}
+@Serializable(with = {{classname}}Serializer::class)
+{{/discriminator}}
+{{/generateOneOfAnyOfWrappers}}
+{{/kotlinx_serialization}}
 {{#isDeprecated}}
@Deprecated(message = "This schema is deprecated.")
 {{/isDeprecated}}
 {{>additionalModelTypeAnnotations}}
+{{#kotlinx_serialization}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}} {
+{{#discriminator.mappedModels}}
+    @JvmInline
+    {{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}} value class {{#fnToOneOfWrapperName}}{{mappingName}}{{/fnToOneOfWrapperName}}(val value: {{modelName}}) : {{classname}}

+{{/discriminator.mappedModels}}
+}
+
+{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}object {{classname}}Serializer : KSerializer<{{classname}}> {
+    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("{{classname}}")
+
+    override fun serialize(encoder: Encoder, value: {{classname}}) {
+        require(encoder is JsonEncoder)
+        val jsonObject = when (value) {
+{{#discriminator.mappedModels}}
+            is {{classname}}.{{#fnToOneOfWrapperName}}{{mappingName}}{{/fnToOneOfWrapperName}} -> {
+                val jsonMap = encoder.json.encodeToJsonElement({{modelName}}.serializer(), value.value).jsonObject.toMutableMap()
+                jsonMap["{{discriminator.propertyBaseName}}"] = JsonPrimitive("{{mappingName}}")
+                JsonObject(jsonMap)
+            }
+{{/discriminator.mappedModels}}
+        }
+        encoder.encodeJsonElement(jsonObject)
+    }
+
+    override fun deserialize(decoder: Decoder): {{classname}} {
+        require(decoder is JsonDecoder)
+        val element = decoder.decodeJsonElement().jsonObject
+
+        val discriminatorValue = element["{{discriminator.propertyBaseName}}"]?.jsonPrimitive?.content
+            ?: throw SerializationException("Missing {{discriminator.propertyBaseName}} field")
+
+        return when (discriminatorValue) {
+{{#discriminator.mappedModels}}
+            "{{mappingName}}" -> {
+                val decoded = decoder.json.decodeFromJsonElement({{modelName}}.serializer(), element)
+                {{classname}}.{{#fnToOneOfWrapperName}}{{mappingName}}{{/fnToOneOfWrapperName}}(decoded)
+            }
+{{/discriminator.mappedModels}}
+            else -> throw SerializationException("Unknown {{classname}} {{discriminator.propertyBaseName}}: $discriminatorValue")
+        }
+    }
+}
+{{/kotlinx_serialization}}
+{{^kotlinx_serialization}}
 {{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}data class {{classname}}(var actualInstance: Any? = null) {

    {{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}class CustomTypeAdapterFactory : TypeAdapterFactory {
@@ -332,4 +412,5 @@ import java.io.IOException
            }
        }
    }
-}
+}
+{{/kotlinx_serialization}}
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
@@ -43,7 +43,7 @@ import java.util.List;
 import java.util.Map;

 import static org.openapitools.codegen.CodegenConstants.*;
-import static org.openapitools.codegen.TestUtils.assertFileContains;
+import static org.openapitools.codegen.languages.KotlinClientCodegen.GENERATE_ONEOF_ANYOF_WRAPPERS;

@SuppressWarnings("static-method")
 public class KotlinClientCodegenModelTest {
@@ -502,7 +502,7 @@ public class KotlinClientCodegenModelTest {
 //        properties.put(CodegenConstants.LIBRARY, ClientLibrary.JVM_KTOR);
        properties.put(CodegenConstants.ENUM_PROPERTY_NAMING, CodegenConstants.ENUM_PROPERTY_NAMING_TYPE.UPPERCASE.toString());
        properties.put(SERIALIZATION_LIBRARY, KotlinClientCodegen.SERIALIZATION_LIBRARY_TYPE.gson.toString());
-        properties.put(KotlinClientCodegen.GENERATE_ONEOF_ANYOF_WRAPPERS, true);
+        properties.put(GENERATE_ONEOF_ANYOF_WRAPPERS, true);
        properties.put(API_PACKAGE, "com.toasttab.service.scim.api");
        properties.put(MODEL_PACKAGE, "com.toasttab.service.scim.models");
        properties.put(PACKAGE_NAME, "com.toasttab.service.scim");
@@ -661,6 +661,7 @@ public class KotlinClientCodegenModelTest {
                .setGeneratorName("kotlin")
                .setAdditionalProperties(new HashMap<>() {{
                    put(CodegenConstants.MODEL_PACKAGE, "model");
+                    put(GENERATE_ONEOF_ANYOF_WRAPPERS, false);
                    put(SERIALIZATION_LIBRARY, "kotlinx_serialization");
                }})
                .setInputSpec("src/test/resources/3_0/kotlin/empty-model.yaml")
--- a/modules/openapi-generator/src/test/resources/3_0/kotlin/polymorphism-oneof-discriminator.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/kotlin/polymorphism-oneof-discriminator.yaml
@@ -0,0 +1,83 @@
+openapi: 3.0.1
+info:
+  title: Example
+  description: An example
+  version: '0.1'
+  contact:
+    email: contact@example.org
+    url: 'https://example.org'
+servers:
+  - url: http://example.org
+tags:
+  - name: bird
+paths:
+  '/v1/bird/{id}':
+    get:
+      tags:
+        - bird
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/animal'
+      operationId: get-bird
+    parameters:
+      - schema:
+          type: string
+          format: uuid
+        name: id
+        in: path
+        required: true
+components:
+  schemas:
+    animal:
+      title: An animal
+      oneOf:
+        - $ref: '#/components/schemas/bird'
+        - $ref: '#/components/schemas/robobird'
+      discriminator:
+        propertyName: discriminator
+        mapping:
+          BIRD: '#/components/schemas/bird'
+          ROBOBIRD: '#/components/schemas/robobird'
+    another_animal:
+      title: Another animal
+      oneOf:
+        - $ref: '#/components/schemas/bird'
+        - $ref: '#/components/schemas/robobird'
+      discriminator:
+        propertyName: another_discriminator
+        mapping:
+          ANOTHER_BIRD: '#/components/schemas/bird'
+          ANOTHER_ROBOBIRD: '#/components/schemas/robobird'
+
+    bird:
+      title: A bird
+      required:
+        - discriminator
+        - another_discriminator
+      properties:
+        propertyA:
+          type: string
+        sameNameProperty:
+          type: integer
+        discriminator:
+          type: string
+        another_discriminator:
+          type: string
+    robobird:
+      title: A robo-bird
+      required:
+        - discriminator
+        - another_discriminator
+      properties:
+        propertyB:
+          type: string
+        sameNameProperty:
+          type: string
+        discriminator:
+          type: string
+        another_discriminator:
+          type: string
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator-ignore
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator-ignore
@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator/FILES
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator/FILES
@@ -0,0 +1,34 @@
+README.md
+build.gradle
+docs/Animal.md
+docs/AnotherAnimal.md
+docs/Bird.md
+docs/BirdApi.md
+docs/Robobird.md
+gradle/wrapper/gradle-wrapper.jar
+gradle/wrapper/gradle-wrapper.properties
+gradlew
+gradlew.bat
+proguard-rules.pro
+settings.gradle
+src/main/kotlin/org/openapitools/client/apis/BirdApi.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+src/main/kotlin/org/openapitools/client/infrastructure/AtomicBooleanAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/AtomicIntegerAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/AtomicLongAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/BigDecimalAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/BigIntegerAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
+src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/OffsetDateTimeAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ResponseExt.kt
+src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
+src/main/kotlin/org/openapitools/client/infrastructure/StringBuilderAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/URIAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/URLAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
+src/main/kotlin/org/openapitools/client/models/Animal.kt
+src/main/kotlin/org/openapitools/client/models/AnotherAnimal.kt
+src/main/kotlin/org/openapitools/client/models/Bird.kt
+src/main/kotlin/org/openapitools/client/models/Robobird.kt
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator/VERSION
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/.openapi-generator/VERSION
@@ -0,0 +1 @@
+7.18.0-SNAPSHOT
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/README.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/README.md
@@ -0,0 +1,70 @@
+# org.openapitools.client - Kotlin client library for Example
+
+An example
+
+## Overview
+This API client was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.  By using the [openapi-spec](https://github.com/OAI/OpenAPI-Specification) from a remote server, you can easily generate an API client.
+
+- API version: 0.1
+- Package version: 
+- Generator version: 7.18.0-SNAPSHOT
+- Build package: org.openapitools.codegen.languages.KotlinClientCodegen
+For more information, please visit [https://example.org](https://example.org)
+
+## Requires
+
+* Kotlin 2.2.20
+* Gradle 8.14
+
+## Build
+
+First, create the gradle wrapper script:
+
+```
+gradle wrapper
+```
+
+Then, run:
+
+```
+./gradlew check assemble
+```
+
+This runs all tests and packages the library.
+
+## Features/Implementation Notes
+
+* Supports JSON inputs/outputs, File inputs, and Form inputs.
+* Supports collection formats for query parameters: csv, tsv, ssv, pipes.
+* Some Kotlin and Java types are fully qualified to avoid conflicts with types defined in OpenAPI definitions.
+* Implementation of ApiClient is intended to reduce method counts, specifically to benefit Android targets.
+
+<a id="documentation-for-api-endpoints"></a>
+## Documentation for API Endpoints
+
+All URIs are relative to *http://example.org*
+
+| Class | Method | HTTP request | Description |
+| ------------ | ------------- | ------------- | ------------- |
+| *BirdApi* | [**getBird**](docs/BirdApi.md#getbird) | **GET** v1/bird/{id} |  |
+
+
+<a id="documentation-for-models"></a>
+## Documentation for Models
+
+ - [org.openapitools.client.models.Animal](docs/Animal.md)
+ - [org.openapitools.client.models.AnotherAnimal](docs/AnotherAnimal.md)
+ - [org.openapitools.client.models.Bird](docs/Bird.md)
+ - [org.openapitools.client.models.Robobird](docs/Robobird.md)
+
+
+<a id="documentation-for-authorization"></a>
+## Documentation for Authorization
+
+Endpoints do not require authorization.
+
+
+
+## Author
+
+contact@example.org
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/build.gradle
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/build.gradle
@@ -0,0 +1,72 @@
+group 'org.openapitools'
+version '1.0.0'
+
+wrapper {
+    gradleVersion = '8.14.3'
+    distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
+}
+
+buildscript {
+    ext.kotlin_version = '2.2.20'
+    ext.retrofitVersion = '3.0.0'
+    ext.spotless_version = "7.2.1"
+
+    repositories {
+        maven { url "https://repo1.maven.org/maven2" }
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
+        classpath "com.diffplug.spotless:spotless-plugin-gradle:$spotless_version"
+    }
+}
+
+apply plugin: 'kotlin'
+apply plugin: 'kotlinx-serialization'
+apply plugin: 'maven-publish'
+apply plugin: 'com.diffplug.spotless'
+
+repositories {
+    maven { url "https://repo1.maven.org/maven2" }
+}
+
+// Use spotless plugin to automatically format code, remove unused import, etc
+// To apply changes directly to the file, run `gradlew spotlessApply`
+// Ref: https://github.com/diffplug/spotless/tree/main/plugin-gradle
+spotless {
+    // comment out below to run spotless as part of the `check` task
+    enforceCheck false
+
+    format 'misc', {
+        // define the files (e.g. '*.gradle', '*.md') to apply `misc` to
+        target '.gitignore'
+
+        // define the steps to apply to those files
+        trimTrailingWhitespace()
+        indentWithSpaces() // Takes an integer argument if you don't like 4
+        endWithNewline()
+    }
+    kotlin {
+        ktfmt()
+    }
+}
+
+test {
+    useJUnitPlatform()
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.9.0"
+    implementation "com.squareup.okhttp3:logging-interceptor:5.1.0"
+    implementation "com.squareup.retrofit2:retrofit:$retrofitVersion"
+    implementation "com.squareup.retrofit2:converter-kotlinx-serialization:$retrofitVersion"
+    implementation "com.squareup.retrofit2:converter-scalars:$retrofitVersion"
+    testImplementation "io.kotlintest:kotlintest-runner-junit5:3.4.2"
+}
+
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).configureEach {
+    kotlinOptions {
+        freeCompilerArgs += "-Xopt-in=kotlinx.serialization.ExperimentalSerializationApi"
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Animal.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Animal.md
@@ -0,0 +1,14 @@
+
+# Animal
+
+## Properties
+| Name | Type | Description | Notes |
+| ------------ | ------------- | ------------- | ------------- |
+| **discriminator** | **kotlin.String** |  |  |
+| **anotherDiscriminator** | **kotlin.String** |  |  |
+| **propertyA** | **kotlin.String** |  |  [optional] |
+| **sameNameProperty** | **kotlin.String** |  |  [optional] |
+| **propertyB** | **kotlin.String** |  |  [optional] |
+
+
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/AnotherAnimal.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/AnotherAnimal.md
@@ -0,0 +1,14 @@
+
+# AnotherAnimal
+
+## Properties
+| Name | Type | Description | Notes |
+| ------------ | ------------- | ------------- | ------------- |
+| **discriminator** | **kotlin.String** |  |  |
+| **anotherDiscriminator** | **kotlin.String** |  |  |
+| **propertyA** | **kotlin.String** |  |  [optional] |
+| **sameNameProperty** | **kotlin.String** |  |  [optional] |
+| **propertyB** | **kotlin.String** |  |  [optional] |
+
+
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Bird.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Bird.md
@@ -0,0 +1,13 @@
+
+# Bird
+
+## Properties
+| Name | Type | Description | Notes |
+| ------------ | ------------- | ------------- | ------------- |
+| **discriminator** | **kotlin.String** |  |  |
+| **anotherDiscriminator** | **kotlin.String** |  |  |
+| **propertyA** | **kotlin.String** |  |  [optional] |
+| **sameNameProperty** | **kotlin.Int** |  |  [optional] |
+
+
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/BirdApi.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/BirdApi.md
@@ -0,0 +1,44 @@
+# BirdApi
+
+All URIs are relative to *http://example.org*
+
+| Method | HTTP request | Description |
+| ------------- | ------------- | ------------- |
+| [**getBird**](BirdApi.md#getBird) | **GET** v1/bird/{id} |  |
+
+
+
+
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.*
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiClient = ApiClient()
+val webService = apiClient.createWebservice(BirdApi::class.java)
+val id : java.util.UUID = 38400000-8cf0-11bd-b23e-10b96e4ef00d // java.util.UUID | 
+
+val result : Animal = webService.getBird(id)
+```
+
+### Parameters
+| Name | Type | Description  | Notes |
+| ------------- | ------------- | ------------- | ------------- |
+| **id** | **java.util.UUID**|  | |
+
+### Return type
+
+[**Animal**](Animal.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/json
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Robobird.md
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/docs/Robobird.md
@@ -0,0 +1,13 @@
+
+# Robobird
+
+## Properties
+| Name | Type | Description | Notes |
+| ------------ | ------------- | ------------- | ------------- |
+| **discriminator** | **kotlin.String** |  |  |
+| **anotherDiscriminator** | **kotlin.String** |  |  |
+| **propertyB** | **kotlin.String** |  |  [optional] |
+| **sameNameProperty** | **kotlin.String** |  |  [optional] |
+
+
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradle/wrapper/gradle-wrapper.jar
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradle/wrapper/gradle-wrapper.jar
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradle/wrapper/gradle-wrapper.properties
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-all.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradlew
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradlew
@@ -0,0 +1,252 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+[ -h "$app_path" ]
+do
+ls=$( ls -ld "$app_path" )
+link=${ls#*' -> '}
+case $link in             #(
+/*)   app_path=$link ;; #(
+*)    app_path=$APP_HOME$link ;;
+esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s
+' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+echo "$*"
+} >&2
+
+die () {
+echo
+echo "$*"
+echo
+exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+CYGWIN* )         cygwin=true  ;; #(
+Darwin* )         darwin=true  ;; #(
+MSYS* | MINGW* )  msys=true    ;; #(
+NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+# IBM's JDK on AIX uses strange locations for the executables
+JAVACMD=$JAVA_HOME/jre/sh/java
+else
+JAVACMD=$JAVA_HOME/bin/java
+fi
+if [ ! -x "$JAVACMD" ] ; then
+die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+else
+JAVACMD=java
+if ! command -v java >/dev/null 2>&1
+then
+die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+case $MAX_FD in #(
+max*)
+# In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+# shellcheck disable=SC2039,SC3045
+MAX_FD=$( ulimit -H -n ) ||
+warn "Could not query maximum file descriptor limit"
+esac
+case $MAX_FD in  #(
+'' | soft) :;; #(
+*)
+# In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+# shellcheck disable=SC2039,SC3045
+ulimit -n "$MAX_FD" ||
+warn "Could not set maximum file descriptor limit to $MAX_FD"
+esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+# Now convert the arguments - kludge to limit ourselves to /bin/sh
+for arg do
+if
+case $arg in                                #(
+-*)   false ;;                            # don't mess with options #(
+/?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+[ -e "$t" ] ;;                      #(
+*)    false ;;
+esac
+then
+arg=$( cygpath --path --ignore --mixed "$arg" )
+fi
+# Roll the args list around exactly as many times as the number of
+# args, so each arg winds up back in the position where it started, but
+# possibly modified.
+#
+# NB: a `for` loop captures its iteration list before it begins, so
+# changing the positional parameters here affects neither the number of
+# iterations, nor the values presented in `arg`.
+shift                   # remove old arg
+set -- "$@" "$arg"      # push replacement arg
+done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+"-Dorg.gradle.appname=$APP_BASE_NAME" \
+-classpath "$CLASSPATH" \
+org.gradle.wrapper.GradleWrapperMain \
+"$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+xargs -n1 |
+sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+tr '\n' ' '
+)" '"$@"'
+
+exec "$JAVACMD" "$@"
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradlew.bat
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/gradlew.bat
@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/proguard-rules.pro
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/proguard-rules.pro
@@ -0,0 +1,11 @@
+-keepattributes *Annotation*, InnerClasses
+-dontnote kotlinx.serialization.AnnotationsKt # core serialization annotations
+
+# kotlinx-serialization-json specific. Add this if you have java.lang.NoClassDefFoundError kotlinx.serialization.json.JsonObjectSerializer
+-keepclassmembers class kotlinx.serialization.json.** { *** Companion; }
+-keepclasseswithmembers class kotlinx.serialization.json.** { kotlinx.serialization.KSerializer serializer(...); }
+
+# project specific.
+-keep,includedescriptorclasses class org.openapitools.client.models.**$$serializer { *; }
+-keepclassmembers class org.openapitools.client.models.** { *** Companion; }
+-keepclasseswithmembers class org.openapitools.client.models.** { kotlinx.serialization.KSerializer serializer(...); }
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/settings.gradle
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'kotlin-oneOf-discriminator'
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/apis/BirdApi.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/apis/BirdApi.kt
@@ -0,0 +1,26 @@
+package org.openapitools.client.apis
+
+import org.openapitools.client.infrastructure.CollectionFormats.*
+import retrofit2.http.*
+import retrofit2.Call
+import okhttp3.RequestBody
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+import org.openapitools.client.models.Animal
+
+interface BirdApi {
+    /**
+     * GET v1/bird/{id}
+     * 
+     * 
+     * Responses:
+     *  - 200: OK
+     *
+     * @param id 
+     * @return [Call]<[Animal]>
+     */
+    @GET("v1/bird/{id}")
+    fun getBird(@Path("id") id: java.util.UUID): Call<Animal>
+
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -0,0 +1,111 @@
+package org.openapitools.client.infrastructure
+
+
+import okhttp3.Call
+import okhttp3.Interceptor
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import okhttp3.logging.HttpLoggingInterceptor
+import retrofit2.Converter
+import retrofit2.CallAdapter
+import retrofit2.converter.scalars.ScalarsConverterFactory
+
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
+import org.openapitools.client.infrastructure.Serializer.kotlinxSerializationJson
+import okhttp3.MediaType.Companion.toMediaType
+
+class ApiClient(
+    private var baseUrl: String = defaultBasePath,
+    private val okHttpClientBuilder: OkHttpClient.Builder? = null,
+    private val callFactory: Call.Factory? = null,
+    private val callAdapterFactories: List<CallAdapter.Factory> = listOf(
+    ),
+    private val converterFactories: List<Converter.Factory> = listOf(
+        ScalarsConverterFactory.create(),
+        kotlinxSerializationJson.asConverterFactory("application/json".toMediaType()),
+    )
+) {
+    private val apiAuthorizations = mutableMapOf<String, Interceptor>()
+    var logger: ((String) -> Unit)? = null
+
+    private val retrofitBuilder: Retrofit.Builder by lazy {
+        Retrofit.Builder()
+            .baseUrl(baseUrl)
+            .apply {
+                callAdapterFactories.forEach {
+                    addCallAdapterFactory(it)
+                }
+            }
+            .apply {
+                converterFactories.forEach {
+                    addConverterFactory(it)
+                }
+            }
+    }
+
+    private val clientBuilder: OkHttpClient.Builder by lazy {
+        okHttpClientBuilder ?: defaultClientBuilder
+    }
+
+    private val defaultClientBuilder: OkHttpClient.Builder by lazy {
+        OkHttpClient()
+            .newBuilder()
+            .addInterceptor(HttpLoggingInterceptor { message -> logger?.invoke(message) }
+                .apply { level = HttpLoggingInterceptor.Level.BODY }
+            )
+    }
+
+    init {
+        normalizeBaseUrl()
+    }
+
+    /**
+     * Adds an authorization to be used by the client
+     * @param authName Authentication name
+     * @param authorization Authorization interceptor
+     * @return ApiClient
+     */
+    fun addAuthorization(authName: String, authorization: Interceptor): ApiClient {
+        if (apiAuthorizations.containsKey(authName)) {
+            throw RuntimeException("auth name $authName already in api authorizations")
+        }
+        apiAuthorizations[authName] = authorization
+        clientBuilder.addInterceptor(authorization)
+        return this
+    }
+
+    fun setLogger(logger: (String) -> Unit): ApiClient {
+        this.logger = logger
+        return this
+    }
+
+    fun <S> createService(serviceClass: Class<S>): S {
+        val usedCallFactory = this.callFactory ?: clientBuilder.build()
+        return retrofitBuilder.callFactory(usedCallFactory).build().create(serviceClass)
+    }
+
+    private fun normalizeBaseUrl() {
+        if (!baseUrl.endsWith("/")) {
+            baseUrl += "/"
+        }
+    }
+
+    private inline fun <T, reified U> Iterable<T>.runOnFirst(callback: U.() -> Unit) {
+        for (element in this) {
+            if (element is U) {
+                callback.invoke(element)
+                break
+            }
+        }
+    }
+
+    companion object {
+        @JvmStatic
+        protected val baseUrlKey: String = "org.openapitools.client.baseUrl"
+
+        @JvmStatic
+        val defaultBasePath: String by lazy {
+            System.getProperties().getProperty(baseUrlKey, "http://example.org")
+        }
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicBooleanAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicBooleanAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.util.concurrent.atomic.AtomicBoolean
+
+object AtomicBooleanAdapter : KSerializer<AtomicBoolean> {
+    override fun serialize(encoder: Encoder, value: AtomicBoolean) {
+        encoder.encodeBoolean(value.get())
+    }
+
+    override fun deserialize(decoder: Decoder): AtomicBoolean = AtomicBoolean(decoder.decodeBoolean())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("AtomicBoolean", PrimitiveKind.BOOLEAN)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicIntegerAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicIntegerAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.util.concurrent.atomic.AtomicInteger
+
+object AtomicIntegerAdapter : KSerializer<AtomicInteger> {
+    override fun serialize(encoder: Encoder, value: AtomicInteger) {
+        encoder.encodeInt(value.get())
+    }
+
+    override fun deserialize(decoder: Decoder): AtomicInteger = AtomicInteger(decoder.decodeInt())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("AtomicInteger", PrimitiveKind.INT)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicLongAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/AtomicLongAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.util.concurrent.atomic.AtomicLong
+
+object AtomicLongAdapter : KSerializer<AtomicLong> {
+    override fun serialize(encoder: Encoder, value: AtomicLong) {
+        encoder.encodeLong(value.get())
+    }
+
+    override fun deserialize(decoder: Decoder): AtomicLong = AtomicLong(decoder.decodeLong())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("AtomicLong", PrimitiveKind.LONG)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/BigDecimalAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/BigDecimalAdapter.kt
@@ -0,0 +1,15 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.math.BigDecimal
+
+object BigDecimalAdapter : KSerializer<BigDecimal> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("BigDecimal", PrimitiveKind.STRING)
+    override fun deserialize(decoder: Decoder): BigDecimal = BigDecimal(decoder.decodeString())
+    override fun serialize(encoder: Encoder, value: BigDecimal) = encoder.encodeString(value.toPlainString())
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/BigIntegerAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/BigIntegerAdapter.kt
@@ -0,0 +1,20 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.math.BigInteger
+
+object BigIntegerAdapter : KSerializer<BigInteger> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("BigInteger", PrimitiveKind.STRING)
+    override fun deserialize(decoder: Decoder): BigInteger {
+        return BigInteger(decoder.decodeString())
+    }
+
+    override fun serialize(encoder: Encoder, value: BigInteger) {
+        encoder.encodeString(value.toString())
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
@@ -0,0 +1,56 @@
+package org.openapitools.client.infrastructure
+
+class CollectionFormats {
+
+    open class CSVParams {
+
+        var params: List<String>
+
+        constructor(params: List<String>) {
+            this.params = params
+        }
+
+        constructor(vararg params: String) {
+            this.params = listOf(*params)
+        }
+
+        override fun toString(): String {
+            return params.joinToString(",")
+        }
+    }
+
+    open class SSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString(" ")
+        }
+    }
+
+    class TSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("\t")
+        }
+    }
+
+    class PIPESParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("|")
+        }
+    }
+
+    class SPACEParams : SSVParams()
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
@@ -0,0 +1,22 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+
+object LocalDateAdapter : KSerializer<LocalDate> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("LocalDate", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: LocalDate) {
+        encoder.encodeString(DateTimeFormatter.ISO_LOCAL_DATE.format(value))
+    }
+
+    override fun deserialize(decoder: Decoder): LocalDate {
+        return LocalDate.parse(decoder.decodeString(), DateTimeFormatter.ISO_LOCAL_DATE)
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
@@ -0,0 +1,22 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+
+object LocalDateTimeAdapter : KSerializer<LocalDateTime> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("LocalDateTime", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: LocalDateTime) {
+        encoder.encodeString(DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(value))
+    }
+
+    override fun deserialize(decoder: Decoder): LocalDateTime {
+        return LocalDateTime.parse(decoder.decodeString(), DateTimeFormatter.ISO_LOCAL_DATE_TIME)
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/OffsetDateTimeAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/OffsetDateTimeAdapter.kt
@@ -0,0 +1,22 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.time.OffsetDateTime
+import java.time.format.DateTimeFormatter
+
+object OffsetDateTimeAdapter : KSerializer<OffsetDateTime> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("OffsetDateTime", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: OffsetDateTime) {
+        encoder.encodeString(DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(value))
+    }
+
+    override fun deserialize(decoder: Decoder): OffsetDateTime {
+        return OffsetDateTime.parse(decoder.decodeString(), DateTimeFormatter.ISO_OFFSET_DATE_TIME)
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/ResponseExt.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/ResponseExt.kt
@@ -0,0 +1,4 @@
+package org.openapitools.client.infrastructure
+
+import retrofit2.Response
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
@@ -0,0 +1,73 @@
+package org.openapitools.client.infrastructure
+
+import java.math.BigDecimal
+import java.math.BigInteger
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.OffsetDateTime
+import java.util.UUID
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonBuilder
+import kotlinx.serialization.modules.SerializersModule
+import kotlinx.serialization.modules.SerializersModuleBuilder
+import java.net.URI
+import java.net.URL
+import java.util.concurrent.atomic.AtomicBoolean
+import java.util.concurrent.atomic.AtomicInteger
+import java.util.concurrent.atomic.AtomicLong
+
+object Serializer {
+    private var isAdaptersInitialized = false
+
+    @JvmStatic
+    val kotlinxSerializationAdapters: SerializersModule by lazy {
+        isAdaptersInitialized = true
+        SerializersModule {
+            contextual(BigDecimal::class, BigDecimalAdapter)
+            contextual(BigInteger::class, BigIntegerAdapter)
+            contextual(LocalDate::class, LocalDateAdapter)
+            contextual(LocalDateTime::class, LocalDateTimeAdapter)
+            contextual(OffsetDateTime::class, OffsetDateTimeAdapter)
+            contextual(UUID::class, UUIDAdapter)
+            contextual(AtomicInteger::class, AtomicIntegerAdapter)
+            contextual(AtomicLong::class, AtomicLongAdapter)
+            contextual(AtomicBoolean::class, AtomicBooleanAdapter)
+            contextual(URI::class, URIAdapter)
+            contextual(URL::class, URLAdapter)
+            contextual(StringBuilder::class, StringBuilderAdapter)
+
+            apply(kotlinxSerializationAdaptersConfiguration)
+        }
+    }
+
+    var kotlinxSerializationAdaptersConfiguration: SerializersModuleBuilder.() -> Unit = {}
+        set(value) {
+            check(!isAdaptersInitialized) {
+                "Cannot configure kotlinxSerializationAdaptersConfiguration after kotlinxSerializationAdapters has been initialized."
+            }
+            field = value
+        }
+
+    private var isJsonInitialized = false
+
+    @JvmStatic
+    val kotlinxSerializationJson: Json by lazy {
+        isJsonInitialized = true
+        Json {
+            serializersModule = kotlinxSerializationAdapters
+            encodeDefaults = true
+            ignoreUnknownKeys = true
+            isLenient = true
+
+            apply(kotlinxSerializationJsonConfiguration)
+        }
+    }
+
+    var kotlinxSerializationJsonConfiguration: JsonBuilder.() -> Unit = {}
+        set(value) {
+            check(!isJsonInitialized) {
+                "Cannot configure kotlinxSerializationJsonConfiguration after kotlinxSerializationJson has been initialized."
+            }
+            field = value
+        }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/StringBuilderAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/StringBuilderAdapter.kt
@@ -0,0 +1,18 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+
+object StringBuilderAdapter : KSerializer<StringBuilder> {
+    override fun serialize(encoder: Encoder, value: StringBuilder) {
+        encoder.encodeString(value.toString())
+    }
+
+    override fun deserialize(decoder: Decoder): StringBuilder = StringBuilder(decoder.decodeString())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("StringBuilder", PrimitiveKind.STRING)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/URIAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/URIAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.net.URI
+
+object URIAdapter : KSerializer<URI> {
+    override fun serialize(encoder: Encoder, value: URI) {
+        encoder.encodeString(value.toASCIIString())
+    }
+
+    override fun deserialize(decoder: Decoder): URI = URI(decoder.decodeString())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("URI", PrimitiveKind.STRING)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/URLAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/URLAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.net.URL
+
+object URLAdapter : KSerializer<URL> {
+    override fun serialize(encoder: Encoder, value: URL) {
+        encoder.encodeString(value.toExternalForm())
+    }
+
+    override fun deserialize(decoder: Decoder): URL = URL(decoder.decodeString())
+
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("URL", PrimitiveKind.STRING)
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
@@ -0,0 +1,21 @@
+package org.openapitools.client.infrastructure
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.SerialDescriptor
+import java.util.UUID
+
+object UUIDAdapter : KSerializer<UUID> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("UUID", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: UUID) {
+        encoder.encodeString(value.toString())
+    }
+
+    override fun deserialize(decoder: Decoder): UUID {
+        return UUID.fromString(decoder.decodeString())
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Animal.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Animal.kt
@@ -0,0 +1,93 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import org.openapitools.client.models.Bird
+import org.openapitools.client.models.Robobird
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+
+/**
+ * 
+ *
+ */
+@Serializable(with = AnimalSerializer::class)
+sealed interface Animal {
+    @JvmInline
+     value class BirdWrapper(val value: Bird) : Animal
+
+    @JvmInline
+     value class RobobirdWrapper(val value: Robobird) : Animal
+
+}
+
+object AnimalSerializer : KSerializer<Animal> {
+    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("Animal")
+
+    override fun serialize(encoder: Encoder, value: Animal) {
+        require(encoder is JsonEncoder)
+        val jsonObject = when (value) {
+            is Animal.BirdWrapper -> {
+                val jsonMap = encoder.json.encodeToJsonElement(Bird.serializer(), value.value).jsonObject.toMutableMap()
+                jsonMap["discriminator"] = JsonPrimitive("BIRD")
+                JsonObject(jsonMap)
+            }
+            is Animal.RobobirdWrapper -> {
+                val jsonMap = encoder.json.encodeToJsonElement(Robobird.serializer(), value.value).jsonObject.toMutableMap()
+                jsonMap["discriminator"] = JsonPrimitive("ROBOBIRD")
+                JsonObject(jsonMap)
+            }
+        }
+        encoder.encodeJsonElement(jsonObject)
+    }
+
+    override fun deserialize(decoder: Decoder): Animal {
+        require(decoder is JsonDecoder)
+        val element = decoder.decodeJsonElement().jsonObject
+
+        val discriminatorValue = element["discriminator"]?.jsonPrimitive?.content
+            ?: throw SerializationException("Missing discriminator field")
+
+        return when (discriminatorValue) {
+            "BIRD" -> {
+                val decoded = decoder.json.decodeFromJsonElement(Bird.serializer(), element)
+                Animal.BirdWrapper(decoded)
+            }
+            "ROBOBIRD" -> {
+                val decoded = decoder.json.decodeFromJsonElement(Robobird.serializer(), element)
+                Animal.RobobirdWrapper(decoded)
+            }
+            else -> throw SerializationException("Unknown Animal discriminator: $discriminatorValue")
+        }
+    }
+}
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/AnotherAnimal.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/AnotherAnimal.kt
@@ -0,0 +1,93 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import org.openapitools.client.models.Bird
+import org.openapitools.client.models.Robobird
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+
+/**
+ * 
+ *
+ */
+@Serializable(with = AnotherAnimalSerializer::class)
+sealed interface AnotherAnimal {
+    @JvmInline
+     value class AnotherBirdWrapper(val value: Bird) : AnotherAnimal
+
+    @JvmInline
+     value class AnotherRobobirdWrapper(val value: Robobird) : AnotherAnimal
+
+}
+
+object AnotherAnimalSerializer : KSerializer<AnotherAnimal> {
+    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("AnotherAnimal")
+
+    override fun serialize(encoder: Encoder, value: AnotherAnimal) {
+        require(encoder is JsonEncoder)
+        val jsonObject = when (value) {
+            is AnotherAnimal.AnotherBirdWrapper -> {
+                val jsonMap = encoder.json.encodeToJsonElement(Bird.serializer(), value.value).jsonObject.toMutableMap()
+                jsonMap["another_discriminator"] = JsonPrimitive("ANOTHER_BIRD")
+                JsonObject(jsonMap)
+            }
+            is AnotherAnimal.AnotherRobobirdWrapper -> {
+                val jsonMap = encoder.json.encodeToJsonElement(Robobird.serializer(), value.value).jsonObject.toMutableMap()
+                jsonMap["another_discriminator"] = JsonPrimitive("ANOTHER_ROBOBIRD")
+                JsonObject(jsonMap)
+            }
+        }
+        encoder.encodeJsonElement(jsonObject)
+    }
+
+    override fun deserialize(decoder: Decoder): AnotherAnimal {
+        require(decoder is JsonDecoder)
+        val element = decoder.decodeJsonElement().jsonObject
+
+        val discriminatorValue = element["another_discriminator"]?.jsonPrimitive?.content
+            ?: throw SerializationException("Missing another_discriminator field")
+
+        return when (discriminatorValue) {
+            "ANOTHER_BIRD" -> {
+                val decoded = decoder.json.decodeFromJsonElement(Bird.serializer(), element)
+                AnotherAnimal.AnotherBirdWrapper(decoded)
+            }
+            "ANOTHER_ROBOBIRD" -> {
+                val decoded = decoder.json.decodeFromJsonElement(Robobird.serializer(), element)
+                AnotherAnimal.AnotherRobobirdWrapper(decoded)
+            }
+            else -> throw SerializationException("Unknown AnotherAnimal another_discriminator: $discriminatorValue")
+        }
+    }
+}
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Bird.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Bird.kt
@@ -0,0 +1,56 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+
+/**
+ * 
+ *
+ * @param discriminator 
+ * @param anotherDiscriminator 
+ * @param propertyA 
+ * @param sameNameProperty 
+ */
+@Serializable
+
+data class Bird (
+
+    @SerialName(value = "discriminator")
+    val discriminator: kotlin.String,
+
+    @SerialName(value = "another_discriminator")
+    val anotherDiscriminator: kotlin.String,
+
+    @SerialName(value = "propertyA")
+    val propertyA: kotlin.String? = null,
+
+    @SerialName(value = "sameNameProperty")
+    val sameNameProperty: kotlin.Int? = null
+
+) {
+
+
+}
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Robobird.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/main/kotlin/org/openapitools/client/models/Robobird.kt
@@ -0,0 +1,56 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+
+/**
+ * 
+ *
+ * @param discriminator 
+ * @param anotherDiscriminator 
+ * @param propertyB 
+ * @param sameNameProperty 
+ */
+@Serializable
+
+data class Robobird (
+
+    @SerialName(value = "discriminator")
+    val discriminator: kotlin.String,
+
+    @SerialName(value = "another_discriminator")
+    val anotherDiscriminator: kotlin.String,
+
+    @SerialName(value = "propertyB")
+    val propertyB: kotlin.String? = null,
+
+    @SerialName(value = "sameNameProperty")
+    val sameNameProperty: kotlin.String? = null
+
+) {
+
+
+}
+
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/apis/BirdApiTest.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/apis/BirdApiTest.kt
@@ -0,0 +1,38 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.apis
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+
+import org.openapitools.client.apis.BirdApi
+import org.openapitools.client.models.Animal
+
+class BirdApiTest : ShouldSpec() {
+    init {
+        // uncomment below to create an instance of BirdApi
+        //val apiInstance = BirdApi()
+
+        // to test getBird
+        should("test getBird") {
+            // uncomment below to test getBird
+            //val id : java.util.UUID = 38400000-8cf0-11bd-b23e-10b96e4ef00d // java.util.UUID | 
+            //val result : Animal = apiInstance.getBird(id)
+            //result shouldBe ("TODO")
+        }
+
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/AnimalTest.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/AnimalTest.kt
@@ -0,0 +1,61 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+
+import org.openapitools.client.models.Animal
+import org.openapitools.client.models.Bird
+import org.openapitools.client.models.Robobird
+
+class AnimalTest : ShouldSpec() {
+    init {
+        // uncomment below to create an instance of Animal
+        //val modelInstance = Animal()
+
+        // to test the property `discriminator`
+        should("test discriminator") {
+            // uncomment below to test the property
+            //modelInstance.discriminator shouldBe ("TODO")
+        }
+
+        // to test the property `anotherDiscriminator`
+        should("test anotherDiscriminator") {
+            // uncomment below to test the property
+            //modelInstance.anotherDiscriminator shouldBe ("TODO")
+        }
+
+        // to test the property `propertyA`
+        should("test propertyA") {
+            // uncomment below to test the property
+            //modelInstance.propertyA shouldBe ("TODO")
+        }
+
+        // to test the property `sameNameProperty`
+        should("test sameNameProperty") {
+            // uncomment below to test the property
+            //modelInstance.sameNameProperty shouldBe ("TODO")
+        }
+
+        // to test the property `propertyB`
+        should("test propertyB") {
+            // uncomment below to test the property
+            //modelInstance.propertyB shouldBe ("TODO")
+        }
+
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/AnotherAnimalTest.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/AnotherAnimalTest.kt
@@ -0,0 +1,61 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+
+import org.openapitools.client.models.AnotherAnimal
+import org.openapitools.client.models.Bird
+import org.openapitools.client.models.Robobird
+
+class AnotherAnimalTest : ShouldSpec() {
+    init {
+        // uncomment below to create an instance of AnotherAnimal
+        //val modelInstance = AnotherAnimal()
+
+        // to test the property `discriminator`
+        should("test discriminator") {
+            // uncomment below to test the property
+            //modelInstance.discriminator shouldBe ("TODO")
+        }
+
+        // to test the property `anotherDiscriminator`
+        should("test anotherDiscriminator") {
+            // uncomment below to test the property
+            //modelInstance.anotherDiscriminator shouldBe ("TODO")
+        }
+
+        // to test the property `propertyA`
+        should("test propertyA") {
+            // uncomment below to test the property
+            //modelInstance.propertyA shouldBe ("TODO")
+        }
+
+        // to test the property `sameNameProperty`
+        should("test sameNameProperty") {
+            // uncomment below to test the property
+            //modelInstance.sameNameProperty shouldBe ("TODO")
+        }
+
+        // to test the property `propertyB`
+        should("test propertyB") {
+            // uncomment below to test the property
+            //modelInstance.propertyB shouldBe ("TODO")
+        }
+
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/BirdTest.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/BirdTest.kt
@@ -0,0 +1,53 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+
+import org.openapitools.client.models.Bird
+
+class BirdTest : ShouldSpec() {
+    init {
+        // uncomment below to create an instance of Bird
+        //val modelInstance = Bird()
+
+        // to test the property `discriminator`
+        should("test discriminator") {
+            // uncomment below to test the property
+            //modelInstance.discriminator shouldBe ("TODO")
+        }
+
+        // to test the property `anotherDiscriminator`
+        should("test anotherDiscriminator") {
+            // uncomment below to test the property
+            //modelInstance.anotherDiscriminator shouldBe ("TODO")
+        }
+
+        // to test the property `propertyA`
+        should("test propertyA") {
+            // uncomment below to test the property
+            //modelInstance.propertyA shouldBe ("TODO")
+        }
+
+        // to test the property `sameNameProperty`
+        should("test sameNameProperty") {
+            // uncomment below to test the property
+            //modelInstance.sameNameProperty shouldBe ("TODO")
+        }
+
+    }
+}
--- a/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/RobobirdTest.kt
+++ b/samples/client/others/kotlin-oneOf-discriminator-kotlinx-serialization/src/test/kotlin/org/openapitools/client/models/RobobirdTest.kt
@@ -0,0 +1,53 @@
+/**
+ *
+ * Please note:
+ * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * Do not edit this file manually.
+ *
+ */
+
+@file:Suppress(
+    "ArrayInDataClass",
+    "EnumEntryName",
+    "RemoveRedundantQualifierName",
+    "UnusedImport"
+)
+
+package org.openapitools.client.models
+
+import io.kotlintest.shouldBe
+import io.kotlintest.specs.ShouldSpec
+
+import org.openapitools.client.models.Robobird
+
+class RobobirdTest : ShouldSpec() {
+    init {
+        // uncomment below to create an instance of Robobird
+        //val modelInstance = Robobird()
+
+        // to test the property `discriminator`
+        should("test discriminator") {
+            // uncomment below to test the property
+            //modelInstance.discriminator shouldBe ("TODO")
+        }
+
+        // to test the property `anotherDiscriminator`
+        should("test anotherDiscriminator") {
+            // uncomment below to test the property
+            //modelInstance.anotherDiscriminator shouldBe ("TODO")
+        }
+
+        // to test the property `propertyB`
+        should("test propertyB") {
+            // uncomment below to test the property
+            //modelInstance.propertyB shouldBe ("TODO")
+        }
+
+        // to test the property `sameNameProperty`
+        should("test sameNameProperty") {
+            // uncomment below to test the property
+            //modelInstance.sameNameProperty shouldBe ("TODO")
+        }
+
+    }
+}
--- a/samples/client/petstore/kotlin-model-prefix-type-mappings/src/main/kotlin/org/openapitools/client/models/ApiUserOrPet.kt
+++ b/samples/client/petstore/kotlin-model-prefix-type-mappings/src/main/kotlin/org/openapitools/client/models/ApiUserOrPet.kt
@@ -35,8 +35,6 @@ import java.io.IOException
 * 
 *
 */
-
-
 data class ApiUserOrPet(var actualInstance: Any? = null) {

    class CustomTypeAdapterFactory : TypeAdapterFactory {
@@ -155,3 +153,4 @@ data class ApiUserOrPet(var actualInstance: Any? = null) {
        }
    }
 }
+
--- a/samples/client/petstore/kotlin-model-prefix-type-mappings/src/main/kotlin/org/openapitools/client/models/ApiUserOrPetOrArrayString.kt
+++ b/samples/client/petstore/kotlin-model-prefix-type-mappings/src/main/kotlin/org/openapitools/client/models/ApiUserOrPetOrArrayString.kt
@@ -35,8 +35,6 @@ import java.io.IOException
 * 
 *
 */
-
-
 data class ApiUserOrPetOrArrayString(var actualInstance: Any? = null) {

    class CustomTypeAdapterFactory : TypeAdapterFactory {
@@ -205,3 +203,4 @@ data class ApiUserOrPetOrArrayString(var actualInstance: Any? = null) {
        }
    }
 }
+
				`@@ -0,0 +1 @@`
				`rootProject.name = 'kotlin-oneOf-discriminator'`