[kotlin] better oneOf, anyOf support

bin/configs/kotlin-model-prefix-type-mapping.yaml

@@ -11,5 +11,6 @@ additionalProperties:
   library: jvm-retrofit2
   enumPropertyNaming: UPPERCASE
   serializationLibrary: gson
+  generateOneOfAnyOfWrappers: true
 openapiNormalizer:
   SIMPLIFY_ONEOF_ANYOF: false

docs/generators/kotlin.md

@@ -25,6 +25,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |collectionType|Option. Collection type to use|<dl><dt>**array**</dt><dd>kotlin.Array</dd><dt>**list**</dt><dd>kotlin.collections.List</dd></dl>|list|
 |dateLibrary|Option. Date library to use|<dl><dt>**threetenbp-localdatetime**</dt><dd>Threetenbp - Backport of JSR310 (jvm only, for legacy app only)</dd><dt>**kotlinx-datetime**</dt><dd>kotlinx-datetime (preferred for multiplatform)</dd><dt>**string**</dt><dd>String</dd><dt>**java8-localdatetime**</dt><dd>Java 8 native JSR310 (jvm only, for legacy app only)</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (jvm only, preferred for jdk 1.8+)</dd><dt>**threetenbp**</dt><dd>Threetenbp - Backport of JSR310 (jvm only, preferred for jdk &lt; 1.8)</dd></dl>|java8|
 |enumPropertyNaming|Naming convention for enum properties: 'camelCase', 'PascalCase', 'snake_case', 'UPPERCASE', and 'original'| |original|
+|generateOneOfAnyOfWrappers|Generate oneOf, anyOf schemas as wrappers.| |false|
 |generateRoomModels|Generate Android Room database models in addition to API models (JVM Volley library only)| |false|
 |groupId|Generated artifact package's organization (i.e. maven groupId).| |org.openapitools|
 |idea|Add IntellJ Idea plugin and mark Kotlin main and test folders as source folders.| |false|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java

@@ -26,6 +26,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import com.samskivert.mustache.Mustache;
 import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.CliOption;
 import org.openapitools.codegen.CodegenConstants;
@@ -89,6 +90,8 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
 
     public static final String SUPPORT_ANDROID_API_LEVEL_25_AND_BELLOW = "supportAndroidApiLevel25AndBelow";
 
+    public static final String GENERATE_ONEOF_ANYOF_WRAPPERS = "generateOneOfAnyOfWrappers";
+
     protected static final String VENDOR_EXTENSION_BASE_NAME_LITERAL = "x-base-name-literal";
 
     protected String dateLibrary = DateLibrary.JAVA8.value;
@@ -102,11 +105,13 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
     protected boolean generateRoomModels = false;
     protected String roomModelPackage = "";
     protected boolean omitGradleWrapper = false;
+    protected boolean generateOneOfAnyOfWrappers = true;
 
     protected String authFolder;
 
     protected SERIALIZATION_LIBRARY_TYPE serializationLibrary = SERIALIZATION_LIBRARY_TYPE.moshi;
     public static final String SERIALIZATION_LIBRARY_DESC = "What serialization library to use: 'moshi' (default), or 'gson' or 'jackson' or 'kotlinx_serialization'";
+
     public enum SERIALIZATION_LIBRARY_TYPE {moshi, gson, jackson, kotlinx_serialization}
 
     public enum DateLibrary {
@@ -259,6 +264,8 @@ public KotlinClientCodegen() {
 
         cliOptions.add(CliOption.newBoolean(SUPPORT_ANDROID_API_LEVEL_25_AND_BELLOW, "[WARNING] This flag will generate code that has a known security vulnerability. It uses `kotlin.io.createTempFile` instead of `java.nio.file.Files.createTempFile` in order to support Android API level 25 and bellow. For more info, please check the following links https://github.com/OpenAPITools/openapi-generator/security/advisories/GHSA-23x4-m842-fmwf, https://github.com/OpenAPITools/openapi-generator/pull/9284"));
 
+        cliOptions.add(CliOption.newBoolean(GENERATE_ONEOF_ANYOF_WRAPPERS, "Generate oneOf, anyOf schemas as wrappers."));
+
         CliOption serializationLibraryOpt = new CliOption(CodegenConstants.SERIALIZATION_LIBRARY, SERIALIZATION_LIBRARY_DESC);
         cliOptions.add(serializationLibraryOpt.defaultValue(serializationLibrary.name()));
     }
@@ -283,6 +290,10 @@ public boolean getOmitGradleWrapper() {
         return omitGradleWrapper;
     }
 
+    public boolean getGenerateOneOfAnyOfWrappers() {
+        return generateOneOfAnyOfWrappers;
+    }
+
     public void setGenerateRoomModels(Boolean generateRoomModels) {
         this.generateRoomModels = generateRoomModels;
     }
@@ -332,6 +343,10 @@ public void setOmitGradleWrapper(boolean omitGradleWrapper) {
         this.omitGradleWrapper = omitGradleWrapper;
     }
 
+    public void setGenerateOneOfAnyOfWrappers(boolean generateOneOfAnyOfWrappers) {
+        this.generateOneOfAnyOfWrappers = generateOneOfAnyOfWrappers;
+    }
+
     public SERIALIZATION_LIBRARY_TYPE getSerializationLibrary() {
         return this.serializationLibrary;
     }
@@ -443,6 +458,10 @@ public void processOpts() {
             additionalProperties.put(this.serializationLibrary.name(), true);
         }
 
+        if (additionalProperties.containsKey(GENERATE_ONEOF_ANYOF_WRAPPERS)) {
+            setGenerateOneOfAnyOfWrappers(Boolean.parseBoolean(additionalProperties.get(GENERATE_ONEOF_ANYOF_WRAPPERS).toString()));
+        }
+
         commonSupportingFiles();
 
         switch (getLibrary()) {
@@ -513,6 +532,14 @@ public void processOpts() {
                 supportingFiles.add(new SupportingFile("auth/HttpBasicAuth.kt.mustache", authFolder, "HttpBasicAuth.kt"));
             }
         }
+
+        additionalProperties.put("sanitizeGeneric", (Mustache.Lambda) (fragment, writer) -> {
+            String content = fragment.execute();
+            for (final String s : List.of("<", ">", ",", " ", ".")) {
+                content = content.replace(s, "");
+            }
+            writer.write(content);
+        });
     }
 
     private void processDateLibrary() {
@@ -874,7 +901,7 @@ public ModelsMap postProcessModels(ModelsMap objs) {
 
         for (ModelMap mo : objects.getModels()) {
             CodegenModel cm = mo.getModel();
-            if (getGenerateRoomModels()) {
+            if (getGenerateRoomModels() || getGenerateOneOfAnyOfWrappers()) {
                 cm.vendorExtensions.put("x-has-data-class-body", true);
             }
 

modules/openapi-generator/src/main/resources/kotlin-client/README.mustache

@@ -59,9 +59,9 @@ This runs all tests and packages the library.
 
 All URIs are relative to *{{{basePath}}}*
 
-Class | Method | HTTP request | Description
------------- | ------------- | ------------- | -------------
-{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}*{{classname}}* | [**{{operationId}}**]({{apiDocPath}}{{classname}}.md#{{operationIdLowerCase}}) | **{{httpMethod}}** {{path}} | {{{summary}}}
+| Class | Method | HTTP request | Description |
+| ------------ | ------------- | ------------- | ------------- |
+{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}| *{{classname}}* | [**{{operationId}}**]({{apiDocPath}}{{classname}}.md#{{operationIdLowerCase}}) | **{{httpMethod}}** {{path}} | {{{summary}}} |
 {{/operation}}{{/operations}}{{/apis}}{{/apiInfo}}
 {{/generateApiDocs}}
 

modules/openapi-generator/src/main/resources/kotlin-client/anyof_class.mustache

@@ -0,0 +1,243 @@
+{{^multiplatform}}
+{{#gson}}
+{{#generateOneOfAnyOfWrappers}}
+import com.google.gson.Gson
+import com.google.gson.JsonElement
+import com.google.gson.TypeAdapter
+import com.google.gson.TypeAdapterFactory
+import com.google.gson.reflect.TypeToken
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.annotations.JsonAdapter
+{{/generateOneOfAnyOfWrappers}}
+import com.google.gson.annotations.SerializedName
+{{/gson}}
+{{#moshi}}
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+{{/moshi}}
+{{#jackson}}
+{{#enumUnknownDefaultCase}}
+import com.fasterxml.jackson.annotation.JsonEnumDefaultValue
+{{/enumUnknownDefaultCase}}
+import com.fasterxml.jackson.annotation.JsonProperty
+{{#discriminator}}
+import com.fasterxml.jackson.annotation.JsonSubTypes
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+{{/discriminator}}
+{{/jackson}}
+{{#kotlinx_serialization}}
+import {{#serializableModel}}kotlinx.serialization.Serializable as KSerializable{{/serializableModel}}{{^serializableModel}}kotlinx.serialization.Serializable{{/serializableModel}}
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Contextual
+{{#enumUnknownDefaultCase}}
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+{{/enumUnknownDefaultCase}}
+{{#hasEnums}}
+{{/hasEnums}}
+{{/kotlinx_serialization}}
+{{#parcelizeModels}}
+import android.os.Parcelable
+import kotlinx.parcelize.Parcelize
+{{/parcelizeModels}}
+{{/multiplatform}}
+{{#multiplatform}}
+import kotlinx.serialization.*
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+{{/multiplatform}}
+{{#serializableModel}}
+import java.io.Serializable
+{{/serializableModel}}
+{{#generateRoomModels}}
+import {{roomModelPackage}}.{{classname}}RoomModel
+import {{packageName}}.infrastructure.ITransformForStorage
+{{/generateRoomModels}}
+import java.io.IOException
+
+/**
+ * {{{description}}}
+ *
+ */
+{{#parcelizeModels}}
+@Parcelize
+{{/parcelizeModels}}
+{{#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}}
+{{#isDeprecated}}
+@Deprecated(message = "This schema is deprecated.")
+{{/isDeprecated}}
+{{>additionalModelTypeAnnotations}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}data class {{classname}}(var actualInstance: Any? = null) {
+
+    class CustomTypeAdapterFactory : TypeAdapterFactory {
+        override fun <T> create(gson: Gson, type: TypeToken<T>): TypeAdapter<T>? {
+            if (!{{classname}}::class.java.isAssignableFrom(type.rawType)) {
+                return null // this class only serializes '{{classname}}' and its subtypes
+            }
+            val elementAdapter = gson.getAdapter(JsonElement::class.java)
+            {{#composedSchemas}}
+            {{#anyOf}}
+            {{^isArray}}
+            {{^vendorExtensions.x-duplicated-data-type}}
+            val adapter{{{dataType}}} = gson.getDelegateAdapter(this, TypeToken.get({{{dataType}}}::class.java))
+            {{/vendorExtensions.x-duplicated-data-type}}
+            {{/isArray}}
+            {{#isArray}}
+            @Suppress("UNCHECKED_CAST")
+            val adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}} = gson.getDelegateAdapter(this, TypeToken.get(object : TypeToken<{{{dataType}}}>() {}.type)) as TypeAdapter<{{{dataType}}}>
+            {{/isArray}}
+            {{/anyOf}}
+            {{/composedSchemas}}
+
+            @Suppress("UNCHECKED_CAST")
+            return object : TypeAdapter<{{classname}}?>() {
+                @Throws(IOException::class)
+                override fun write(out: JsonWriter,value: {{classname}}?) {
+                    if (value?.actualInstance == null) {
+                        elementAdapter.write(out, null)
+                        return
+                    }
+
+                    {{#composedSchemas}}
+                    {{#anyOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
+                    // check if the actual instance is of the type `{{{dataType}}}`
+                    if (value.actualInstance is {{#isArray}}List<*>{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}) {
+                    {{#isPrimitiveType}}
+                        val primitive = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}.toJsonTree(value.actualInstance as {{{dataType}}}?).getAsJsonPrimitive()
+                        elementAdapter.write(out, primitive)
+                        return
+                    {{/isPrimitiveType}}
+                    {{^isPrimitiveType}}
+                    {{#isArray}}
+                        List<?> list = (List<?>) value.actualInstance
+                        if (list.get(0) is {{{items.dataType}}}) {
+                            val array = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}.toJsonTree(value.actualInstance as {{{dataType}}}?).getAsJsonArray()
+                            elementAdapter.write(out, array)
+                            return
+                        }
+                    {{/isArray}}
+                    {{/isPrimitiveType}}
+                    {{^isArray}}
+                    {{^isPrimitiveType}}
+                        val element = adapter{{{dataType}}}.toJsonTree(value.actualInstance as {{{dataType}}}?)
+                        elementAdapter.write(out, element)
+                        return
+                    {{/isPrimitiveType}}
+                    {{/isArray}}
+                    }
+                    {{/vendorExtensions.x-duplicated-data-type}}
+                    {{/anyOf}}
+                    {{/composedSchemas}}
+                    throw IOException("Failed to serialize as the type doesn't match anyOf schemas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}")
+                }
+
+                @Throws(IOException::class)
+                override fun read(jsonReader: JsonReader): {{classname}} {
+                    val jsonElement = elementAdapter.read(jsonReader)
+                    val errorMessages = ArrayList<String>()
+                    var actualAdapter: TypeAdapter<*>
+                    val ret = {{classname}}()
+
+                    {{#composedSchemas}}
+                    {{#anyOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
+                    {{^hasVars}}
+                    // deserialize {{{dataType}}}
+                    try {
+                        // validate the JSON object to see if any exception is thrown
+                    {{^isArray}}
+                    {{#isNumber}}
+                        require(jsonElement.getAsJsonPrimitive().isNumber()) {
+                            String.format("Expected json element to be of type Number in the JSON string but got `%s`", jsonElement.toString())
+                        }
+                        actualAdapter = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}
+                        ret.actualInstance = actualAdapter.fromJsonTree(jsonElement)
+                        return ret
+                    {{/isNumber}}
+                    {{^isNumber}}
+                    {{#isPrimitiveType}}
+                        require(jsonElement.getAsJsonPrimitive().is{{#isBoolean}}Boolean{{/isBoolean}}{{#isString}}String{{/isString}}{{^isString}}{{^isBoolean}}Number{{/isBoolean}}{{/isString}}()) {
+                            String.format("Expected json element to be of type {{#isBoolean}}Boolean{{/isBoolean}}{{#isString}}String{{/isString}}{{^isString}}{{^isBoolean}}Number{{/isBoolean}}{{/isString}} in the JSON string but got `%s`", jsonElement.toString())
+                        }
+                        actualAdapter = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}
+                        ret.actualInstance = actualAdapter.fromJsonTree(jsonElement)
+                        return ret
+                    {{/isPrimitiveType}}
+                    {{/isNumber}}
+                    {{^isNumber}}
+                    {{^isPrimitiveType}}
+                        {{{dataType}}}.validateJsonElement(jsonElement)
+                        actualAdapter = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}
+                        ret.actualInstance = actualAdapter.fromJsonTree(jsonElement)
+                        return ret
+                    {{/isPrimitiveType}}
+                    {{/isNumber}}
+                    {{/isArray}}
+                    {{#isArray}}
+                        require(jsonElement.isJsonArray) {
+                            String.format("Expected json element to be a array type in the JSON string but got `%s`", jsonElement.toString())
+                        }
+
+                        // validate array items
+                        for(element in jsonElement.getAsJsonArray()) {
+                        {{#items}}
+                        {{#isNumber}}
+                            require(jsonElement.getAsJsonPrimitive().isNumber) {
+                                String.format("Expected json element to be of type Number in the JSON string but got `%s`", jsonElement.toString())
+                            }
+                        {{/isNumber}}
+                        {{^isNumber}}
+                        {{#isPrimitiveType}}
+                            require(element.getAsJsonPrimitive().is{{#isBoolean}}Boolean{{/isBoolean}}{{#isString}}String{{/isString}}{{^isString}}{{^isBoolean}}Number{{/isBoolean}}{{/isString}}) {
+                                String.format("Expected array items to be of type {{#isBoolean}}Boolean{{/isBoolean}}{{#isString}}String{{/isString}}{{^isString}}{{^isBoolean}}Number{{/isBoolean}}{{/isString}} in the JSON string but got `%s`", jsonElement.toString())
+                            }
+                        {{/isPrimitiveType}}
+                        {{/isNumber}}
+                        {{^isNumber}}
+                        {{^isPrimitiveType}}
+                            {{{dataType}}}.validateJsonElement(element)
+                        {{/isPrimitiveType}}
+                        {{/isNumber}}
+                        {{/items}}
+                        }
+                        actualAdapter = adapter{{#sanitizeGeneric}}{{{dataType}}}{{/sanitizeGeneric}}
+                        ret.actualInstance = actualAdapter.fromJsonTree(jsonElement)
+                        return ret
+                    {{/isArray}}
+                        //log.log(Level.FINER, "Input data matches schema '{{{dataType}}}'")
+                    } catch (e: Exception) {
+                        // deserialization failed, continue
+                        errorMessages.add(String.format("Deserialization for {{{dataType}}} failed with `%s`.", e.message))
+                        //log.log(Level.FINER, "Input data does not match schema '{{{dataType}}}'", e)
+                    }
+                    {{/hasVars}}
+                    {{#hasVars}}
+                    // deserialize {{{.}}}
+                    try {
+                        // validate the JSON object to see if any exception is thrown
+                        {{.}}.validateJsonElement(jsonElement)
+                        log.log(Level.FINER, "Input data matches schema '{{{.}}}'")
+                        actualAdapter = adapter{{.}}
+                        ret.actualInstance = actualAdapter.fromJsonTree(jsonElement)
+                        return ret
+                    } catch (e: Exception) {
+                        // deserialization failed, continue
+                        errorMessages.add(String.format("Deserialization for {{{.}}} failed with `%s`.", e.message))
+                        //log.log(Level.FINER, "Input data does not match schema '{{{.}}}'", e)
+                    }
+                    {{/hasVars}}
+                    {{/vendorExtensions.x-duplicated-data-type}}
+                    {{/anyOf}}
+                    {{/composedSchemas}}
+
+                    throw IOException(String.format("Failed deserialization for {{classname}}: no schema match result. Detailed failure message for anyOf schemas: %s. JSON: %s", errorMessages, jsonElement.toString()))
+                }
+            }.nullSafe() as TypeAdapter<T>
+        }
+    }
+}