[java] fix: okhttp-gson additionalProperties field makes every allOf child undeserializable

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/additional_properties.mustache

@@ -3,8 +3,12 @@
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -2024,6 +2024,36 @@ public void testJdkHttpClientWithAndWithoutParentExtension() {
                 .content().contains("public class AnotherChild {");
     }
 
+    @Test
+    public void testAdditionalPropertiesFieldIsTransientForGson() {
+        final Path output = newTempFolder();
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName(JAVA_GENERATOR)
+                // use default `okhttp-gson`
+                .addAdditionalProperty(CodegenConstants.API_PACKAGE, "xyz.abcdef.api")
+                .addAdditionalProperty(CodegenConstants.MODEL_PACKAGE, "xyz.abcdef.model")
+                .addAdditionalProperty(CodegenConstants.INVOKER_PACKAGE, "xyz.abcdef.invoker")
+                .addAdditionalProperty("disallowAdditionalPropertiesIfNotPresent", "false")
+                .setInputSpec("src/test/resources/3_0/allOf_extension_parent.yaml")
+                .setOutputDir(output.toString().replace("\\", "/"));
+
+        DefaultGenerator generator = new DefaultGenerator();
+        generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
+        generator.opts(configurator.toClientOptInput()).generate();
+
+        // gson's reflective adapter refuses a class with two JSON fields of one name; without
+        // `transient` an allOf child declares additionalProperties itself and inherits it too,
+        // making it undeserializable ("declares multiple JSON fields named
+        // 'additionalProperties'"). The bag is read and written by the model's own
+        // TypeAdapterFactory, never by gson reflection, so hiding the field changes nothing else.
+        assertThat(output.resolve("src/main/java/xyz/abcdef/model/Child.java"))
+                .content()
+                .contains("public class Child extends Person {")
+                .contains("private transient Map<String, Object> additionalProperties;");
+        assertThat(output.resolve("src/main/java/xyz/abcdef/model/Person.java"))
+                .content().contains("private transient Map<String, Object> additionalProperties;");
+    }
+
     @Test
     public void allOfWithSeveralRefsAndRefAsParentInAllOfNormalizationIsTrue() {
         final Path output = newTempFolder();

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AllOfSimpleModel.java

@@ -91,8 +91,12 @@ public void setArrayOfStrings(@javax.annotation.Nonnull List<String> arrayOfStri
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Animal.java

@@ -106,8 +106,12 @@ public void setColor(@javax.annotation.Nullable String color) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java

@@ -148,8 +148,12 @@ public void setRefArrayPrefixItems(@javax.annotation.Nullable List<Object> refAr
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java

@@ -156,8 +156,12 @@ public void setArrayFooThree(@javax.annotation.Nullable List<Tag> arrayFooThree)
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Cat.java

@@ -83,8 +83,12 @@ public void setDeclawed(@javax.annotation.Nullable Boolean declawed) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Category.java

@@ -105,8 +105,12 @@ public void setName(@javax.annotation.Nullable String name) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference1.java

@@ -82,8 +82,12 @@ public void setProp1(@javax.annotation.Nullable CircularReference2 prop1) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference2.java

@@ -82,8 +82,12 @@ public void setProp1(@javax.annotation.Nullable CircularReference3 prop1) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/CircularReference3.java

@@ -82,8 +82,12 @@ public void setProp1(@javax.annotation.Nullable CircularReference1 prop1) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Dog.java

@@ -83,8 +83,12 @@ public void setBreed(@javax.annotation.Nullable String breed) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequest.java

@@ -131,8 +131,12 @@ public void setEvent(@javax.annotation.Nonnull FakeWebhooksSourcesDeletedPostReq
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/FakeWebhooksSourcesDeletedPostRequestEvent.java

@@ -81,8 +81,12 @@ public void setEventId(@javax.annotation.Nonnull String eventId) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ModelApiResponse.java

@@ -129,8 +129,12 @@ public void setMessage(@javax.annotation.Nullable String message) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Order.java

@@ -256,8 +256,12 @@ public void setComplete(@javax.annotation.Nullable Boolean complete) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java

@@ -280,8 +280,12 @@ public void setStatus(@javax.annotation.Nullable StatusEnum status) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/PetWithTypesObjectNullAndRef.java

@@ -107,8 +107,12 @@ public void setSecondProperty(@javax.annotation.Nullable Object secondProperty)
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SelfReferenceAdditionalProperties.java

@@ -81,8 +81,12 @@ public void setDummy(@javax.annotation.Nullable String dummy) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/SimpleModelWithArrayProperty.java

@@ -91,8 +91,12 @@ public void setArrayOfStrings(@javax.annotation.Nonnull List<String> arrayOfStri
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Tag.java

@@ -105,8 +105,12 @@ public void setName(@javax.annotation.Nullable String name) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/User.java

@@ -249,8 +249,12 @@ public void setUserStatus(@javax.annotation.Nullable Integer userStatus) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Category.java

@@ -105,8 +105,12 @@ public void setName(@javax.annotation.Nullable String name) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/ModelApiResponse.java

@@ -129,8 +129,12 @@ public void setMessage(@javax.annotation.Nullable String message) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.

samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Order.java

@@ -256,8 +256,12 @@ public void setComplete(@javax.annotation.Nullable Boolean complete) {
    * A container for additional, undeclared properties.
    * This is a holder for any undeclared properties as specified with
    * the 'additionalProperties' keyword in the OAS document.
+   *
+   * Transient: the bag is read and written by this model's TypeAdapterFactory, and hiding
+   * it from gson's reflection keeps an allOf child (which also inherits the field from its
+   * parent) from declaring two JSON fields of one name.
    */
-  private Map<String, Object> additionalProperties;
+  private transient Map<String, Object> additionalProperties;
 
   /**
    * Set the additional (undeclared) property with the specified name and value.