[Protobuf Schema] Map Field Handling in Composed Schemas (#21002)

* Address map under composed schema

Add explanation to code block

* add comment to explain the code block

Author: lucy66hw

Diff for: modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java

@@ -406,15 +406,15 @@ private void processNestedSchemas(Schema schema, Set<Schema> visitedSchemas) {
         if (ModelUtils.isMapSchema(schema) && ModelUtils.getAdditionalProperties(schema) != null) {
             Schema mapValueSchema = ModelUtils.getAdditionalProperties(schema);
             mapValueSchema = ModelUtils.getReferencedSchema(openAPI, mapValueSchema);
-            if (ModelUtils.isArraySchema(mapValueSchema) || ModelUtils.isMapSchema(mapValueSchema)) {
+            if (ModelUtils.isArraySchema(mapValueSchema) || (ModelUtils.isMapSchema(mapValueSchema) && !ModelUtils.isModel(mapValueSchema))) {
                 Schema innerSchema = generateNestedSchema(mapValueSchema, visitedSchemas);
                 schema.setAdditionalProperties(innerSchema);
 
             }
         } else if (ModelUtils.isArraySchema(schema) && ModelUtils.getSchemaItems(schema) != null) {
             Schema arrayItemSchema = ModelUtils.getSchemaItems(schema);
             arrayItemSchema = ModelUtils.getReferencedSchema(openAPI, arrayItemSchema);
-            if (ModelUtils.isMapSchema(arrayItemSchema) || ModelUtils.isArraySchema(arrayItemSchema)) {
+            if ((ModelUtils.isMapSchema(arrayItemSchema) && !ModelUtils.isModel(arrayItemSchema)) || ModelUtils.isArraySchema(arrayItemSchema)) {
                 Schema innerSchema = generateNestedSchema(arrayItemSchema, visitedSchemas);
                 schema.setItems(innerSchema);
             }
@@ -427,7 +427,7 @@ private void processNestedSchemas(Schema schema, Set<Schema> visitedSchemas) {
                     Schema innerSchema = generateNestedSchema(oneOfSchema, visitedSchemas);
                     innerSchema.setTitle(oneOf.getTitle());
                     newOneOfs.add(innerSchema);
-                } else if (ModelUtils.isMapSchema(oneOfSchema)) {
+                } else if (ModelUtils.isMapSchema(oneOfSchema) && !ModelUtils.isModel(oneOfSchema)) {
                     Schema innerSchema = generateNestedSchema(oneOfSchema, visitedSchemas);
                     innerSchema.setTitle(oneOf.getTitle());
                     newOneOfs.add(innerSchema);
@@ -1061,4 +1061,38 @@ public GeneratorLanguage generatorLanguage() {
         return GeneratorLanguage.PROTOBUF;
     }
 
+
+/**
+ * Handles additionalProperties defined in composed schemas (e.g., allOf) by injecting into the model's properties.
+ * Example:
+ *  components:
+ *    schemas:
+ *      Dog:
+ *        allOf:
+ *          - $ref: '#/components/schemas/DogBase'
+ *          - type: object
+ *            additionalProperties:
+ *              title: pet
+ *              $ref: '#/components/schemas/Pet'
+ * In this case, the second allOf that defines a map with string keys and Pet values will be part of model's property.
+ */
+    @Override
+    protected void addProperties(Map<String, Schema> properties, List<String> required, Schema schema, Set<Schema> visitedSchemas){
+        super.addProperties(properties, required, schema, visitedSchemas);
+        if(schema.getAdditionalProperties() != null) {
+            String addtionalPropertiesName = "default_map";
+            if(schema.getTitle() != null) {
+                addtionalPropertiesName = schema.getTitle();
+            } else {
+                Schema additionalProperties = ModelUtils.getAdditionalProperties(schema);
+                if (additionalProperties.getTitle() != null) {
+                    addtionalPropertiesName = additionalProperties.getTitle();
+                } else if (additionalProperties.get$ref() != null) {
+                    String ref = ModelUtils.getSimpleRef(additionalProperties.get$ref());
+                    addtionalPropertiesName = toVarName(toModelName(ref));
+                }
+            }
+            properties.put(addtionalPropertiesName, schema);
+        }
+    }
 }

Diff for: modules/openapi-generator/src/test/resources/3_0/protobuf/petstore-complex.yaml

@@ -34,13 +34,22 @@ externalDocs:
 components:
   schemas:
     Dog:
-      type: object
-      properties:
-        bark:
-          type: boolean
-        breed:
-          type: string
-          enum: [ Dingo, Husky, Retriever, Shepherd ]
+      allOf:
+        - type: object
+          properties:
+            bark:
+              type: boolean
+            breed:
+              type: string
+              enum: [Dingo, Husky, Retriever, Shepherd]
+        - type: object
+          propertyNames:
+            title: field
+            type: string
+          additionalProperties:
+            title: pet
+            $ref: '#/components/schemas/Pet'
+          minProperties: 1
     Cat:
       type: object
       properties:
@@ -100,31 +109,26 @@ components:
           format: int64
         category:
           $ref: '#/components/schemas/Category'
-      name:
-        type: string
-      photoUrls:
-        type: array
-        xml:
-          name: photoUrl
-          wrapped: true
-        items:
+        name:
           type: string
-      tags:
-        type: array
-        xml:
-          name: tag
-          wrapped: true
-        items:
+        photoUrls:
           type: array
-          additionalProperties:
-            $ref: '#/components/schemas/Tag'
-      status:
-        type: string
-        description: pet status in the store
-        deprecated: true
-        enum:
-          - available
-          - pending
-          - sold
-      xml:
-        name: Pet
+          xml:
+            name: photoUrl
+            wrapped: true
+          items:
+            type: string
+        tags:
+          type: array
+          items:
+            type: object
+            additionalProperties:
+              $ref: '#/components/schemas/Tag'
+        status:
+          type: string
+          description: pet status in the store
+          deprecated: true
+          enum:
+            - available
+            - pending
+            - sold

Diff for: samples/config/petstore/protobuf-schema-config-complex/.openapi-generator/FILES

@@ -6,5 +6,6 @@ models/pet.proto
 models/string_array.proto
 models/string_map.proto
 models/tag.proto
+models/tag_map.proto
 models/tag_name.proto
 services/default_service.proto

Diff for: samples/config/petstore/protobuf-schema-config-complex/models/dog.proto

@@ -12,6 +12,7 @@ syntax = "proto3";
 
 package petstore;
 
+import public "models/pet.proto";
 
 message Dog {
 
@@ -27,5 +28,7 @@ message Dog {
 
   Breed breed = 2;
 
+  map<string, Pet> pet = 3;
+
 }
 

Diff for: samples/config/petstore/protobuf-schema-config-complex/models/pet.proto

@@ -13,12 +13,29 @@ syntax = "proto3";
 package petstore;
 
 import public "models/category.proto";
+import public "models/tag_map.proto";
 
 message Pet {
 
   int64 id = 1;
 
   Category category = 2;
 
+  string name = 3;
+
+  repeated string photo_urls = 4 [json_name="photoUrls"];
+
+  repeated TagMap tags = 5;
+
+  // pet status in the store
+  enum Status {
+    STATUS_UNSPECIFIED = 0;
+    STATUS_AVAILABLE = 1;
+    STATUS_PENDING = 2;
+    STATUS_SOLD = 3;
+  }
+
+  Status status = 6;
+
 }
 

Diff for: samples/config/petstore/protobuf-schema-config-complex/models/tag_map.proto

@@ -0,0 +1,22 @@
+/*
+  OpenAPI Petstore
+
+  This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+
+  The version of the OpenAPI document: 1.0.0
+
+  Generated by OpenAPI Generator: https://openapi-generator.tech
+*/
+
+syntax = "proto3";
+
+package petstore;
+
+import public "models/tag.proto";
+
+message TagMap {
+
+  map<string, Tag> tag_map = 1;
+
+}
+