[Protobuf Schema] Add Support for Multiple Response

bin/configs/protobuf-schema-config.yaml

@@ -8,6 +8,7 @@ additionalProperties:
   numberedFieldNumberList: true
   startEnumsWithUnspecified: true
   wrapComplexType: false
+  supportMultipleResponses: false
   aggregateModelsName: data
 typeMappings:
   object: "google.protobuf.Struct"

docs/generators/protobuf-schema.md

@@ -22,6 +22,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |aggregateModelsName|Aggregated model filename. If set, all generated models will be combined into this single file.| |null|
 |numberedFieldNumberList|Field numbers in order.| |false|
 |startEnumsWithUnspecified|Introduces "UNSPECIFIED" as the first element of enumerations.| |false|
+|supportMultipleResponses|Support multiple responses| |true|
 |wrapComplexType|Generate Additional message for complex type| |true|
 
 ## IMPORT MAPPING

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

@@ -68,6 +68,8 @@ public class ProtobufSchemaCodegen extends DefaultCodegen implements CodegenConf
 
     public static final String AGGREGATE_MODELS_NAME = "aggregateModelsName";
 
+    public static final String SUPPORT_MULTIPLE_RESPONSES = "supportMultipleResponses";
+
     private final Logger LOGGER = LoggerFactory.getLogger(ProtobufSchemaCodegen.class);
 
     @Setter protected String packageName = "openapitools";
@@ -82,6 +84,8 @@ public class ProtobufSchemaCodegen extends DefaultCodegen implements CodegenConf
 
     private boolean wrapComplexType = true;
 
+    private boolean supportMultipleResponses = true;
+
     @Override
     public CodegenType getTag() {
         return CodegenType.SCHEMA;
@@ -192,6 +196,7 @@ public ProtobufSchemaCodegen() {
         addSwitch(START_ENUMS_WITH_UNSPECIFIED, "Introduces \"UNSPECIFIED\" as the first element of enumerations.", startEnumsWithUnspecified);
         addSwitch(ADD_JSON_NAME_ANNOTATION, "Append \"json_name\" annotation to message field when the specification name differs from the protobuf field name", addJsonNameAnnotation);
         addSwitch(WRAP_COMPLEX_TYPE, "Generate Additional message for complex type", wrapComplexType);
+        addSwitch(SUPPORT_MULTIPLE_RESPONSES, "Support multiple responses", supportMultipleResponses);
         addOption(AGGREGATE_MODELS_NAME, "Aggregated model filename. If set, all generated models will be combined into this single file.", null);
     }
 
@@ -239,6 +244,12 @@ public void processOpts() {
             this.setAggregateModelsName((String) additionalProperties.get(AGGREGATE_MODELS_NAME));
         }
 
+        if (additionalProperties.containsKey(this.SUPPORT_MULTIPLE_RESPONSES)) {
+            this.supportMultipleResponses = convertPropertyToBooleanAndWriteBack(SUPPORT_MULTIPLE_RESPONSES);
+        } else {
+            additionalProperties.put(this.SUPPORT_MULTIPLE_RESPONSES, this.supportMultipleResponses);
+        }
+
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
     }
 
@@ -442,7 +453,6 @@ private void wrapModels() {
             } else if (ModelUtils.isAnyOf(schema)) {
                 wrapComposedChildren(schema.getAnyOf(), visitedSchema);
             }
-
         }
     }
 
@@ -475,7 +485,6 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
         }
     }
 
-
     /**
      * Adds prefix to the enum allowable values
      * NOTE: Enum values use C++ scoping rules, meaning that enum values are siblings of their type, not children of it. Therefore, enum value must be unique
@@ -522,7 +531,9 @@ public void addUnspecifiedToAllowableValues(Map<String, Object> allowableValues)
 
             if (allowableValues.containsKey("values")) {
                 List<String> values = (List<String>) allowableValues.get("values");
-                values.add(0, "UNSPECIFIED");
+                List<String> modifiableValues = new ArrayList<>(values);
+                modifiableValues.add(0, "UNSPECIFIED");
+                allowableValues.put("values", modifiableValues);
             }
         }
     }
@@ -542,24 +553,28 @@ public void addEnumIndexes(List<Map<String, Object>> enumVars) {
 
     public List<CodegenProperty> processOneOfAnyOfItems(List<CodegenProperty> composedSchemasProperty) {
         for(CodegenProperty cd: composedSchemasProperty) {
-            if (cd.getTitle() != null) {
-                cd.name = cd.getTitle();
-                cd.baseName = cd.getTitle();
-            } else{
-                cd.name = getNameFromDataType(cd);
-                cd.baseName = getNameFromDataType(cd);
-            }
+            cd.name = resolveVarName(cd);
+            cd.baseName = resolveVarName(cd);
         }
         return composedSchemasProperty;
     }
 
+
+    private String resolveVarName(CodegenProperty property) {
+        if(property.getTitle() != null) {
+            return toVarName(property.getTitle());
+        } else {
+            return getNameFromDataType(property);
+        }
+    }
+
     public String getNameFromDataType(CodegenProperty property) {
         if (Boolean.TRUE.equals(property.getIsArray())){
-            return underscore(property.mostInnerItems.dataType + ARRAY_SUFFIX);
+            return toVarName(property.mostInnerItems.dataType + ARRAY_SUFFIX);
         } else if (Boolean.TRUE.equals(property.getIsMap())) {
-            return underscore(property.mostInnerItems.dataType + MAP_SUFFIX);
+            return toVarName(property.mostInnerItems.dataType + MAP_SUFFIX);
         } else {
-            return underscore(property.dataType);
+            return toVarName(property.dataType);
         }
     }
 
@@ -944,12 +959,41 @@ public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<Mo
                     }
                 }
             }
+
+            if(this.supportMultipleResponses) {
+                int responseIdx = 1;
+                op.vendorExtensions.put("x-grpc-response", op.operationId+"Response");
+                for (CodegenResponse r : op.responses) {
+                    if (r.returnProperty == null) {
+                        r.vendorExtensions.put("x-oneOf-response-type", "google.protobuf.Empty");
+                        r.vendorExtensions.put("x-oneOf-response-name", "empty");
+                    } else if (r.isMap && r.additionalProperties != null) {
+                        r.vendorExtensions.put("x-oneOf-response-type", r.returnProperty.additionalProperties.dataType);
+                        r.vendorExtensions.put("x-oneOf-response-name", resolveVarName(r.returnProperty.additionalProperties));
+                        LOGGER.warn("Mapping responses for operations with supportMultipleResponses flag (operation ID: {}) is not currently supported.", op.operationId);
+                    } else if (r.isArray && r.items != null) {
+                        r.vendorExtensions.put("x-oneOf-response-type", r.returnProperty.items.dataType);
+                        r.vendorExtensions.put("x-oneOf-response-name", resolveVarName(r.returnProperty.items));
+                        LOGGER.warn("Array responses for operations with supportMultipleResponses flag (operation ID: {}) is not currently supported.", op.operationId);
+                    }
+                    else {
+                        r.vendorExtensions.put("x-oneOf-response-type", r.returnProperty.dataType);
+                        r.vendorExtensions.put("x-oneOf-response-name", resolveVarName(r.returnProperty));
+                    }
+                    r.vendorExtensions.put("x-oneOf-response-index", responseIdx++);
+                }
+            }
         }
 
         if (this.aggregateModelsName != null) {
+            List<Map<String, String>> imports = objs.getImports().stream()
+                    .filter(importMap -> !importMap.get("import").startsWith("models/"))
+                    .collect(Collectors.toList());
+
             List<Map<String, String>> aggregate_imports = Collections.singletonList(Collections
                     .singletonMap(IMPORT, toModelImport(this.aggregateModelsName)));
-            objs.setImports(aggregate_imports);
+            imports.addAll(aggregate_imports);
+            objs.setImports(imports);
         }
         return objs;
     }

modules/openapi-generator/src/main/resources/protobuf-schema/api.mustache

@@ -42,5 +42,14 @@ message {{operationId}}Response {
 }
 
 {{/vendorExtensions.x-grpc-response}}
+{{#supportMultipleResponses}}
+message {{operationId}}Response {
+    oneof response {
+    {{#responses}}
+        {{{vendorExtensions.x-oneOf-response-type}}} {{vendorExtensions.x-oneOf-response-name}}_{{code}} = {{vendorExtensions.x-oneOf-response-index}};
+    {{/responses}}
+    }
+}
+{{/supportMultipleResponses}}
 {{/operation}}
 {{/operations}}

modules/openapi-generator/src/test/resources/3_0/protobuf/petstore.yaml

@@ -59,7 +59,7 @@ paths:
               schema:
                 $ref: '#/components/schemas/Pet'
         '405':
-          description: Invalid input
+          $ref: '#/components/responses/ErrorResponse'
       security:
         - petstore_auth:
             - 'write:pets'
@@ -83,11 +83,11 @@ paths:
               schema:
                 $ref: '#/components/schemas/Pet'
         '400':
-          description: Invalid ID supplied
+          $ref: '#/components/responses/ErrorResponse'
         '404':
-          description: Pet not found
+          $ref: '#/components/responses/ErrorResponse'
         '405':
-          description: Validation exception
+          $ref: '#/components/responses/ErrorResponse'
       security:
         - petstore_auth:
             - 'write:pets'
@@ -593,6 +593,13 @@ externalDocs:
   description: Find out more about Swagger
   url: 'http://swagger.io'
 components:
+  responses:
+    ErrorResponse:
+      description: An error response.
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Error'
   requestBodies:
     UserArray:
       content:
@@ -786,3 +793,16 @@ components:
           uniqueItems: true
           items:
             type: string
+    Error:
+      type: object
+      required:
+        - code
+        - message
+      properties:
+        code:
+          type: integer
+          format: int32
+          description: Error code.
+        message:
+          type: string
+          description: Detailed error message.

samples/config/petstore/protobuf-schema-config-complex/services/default_service.proto

@@ -16,7 +16,7 @@ import "google/protobuf/empty.proto";
 import public "models/cat.proto";
 
 service DefaultService {
-  rpc PetsGet (PetsGetRequest) returns (google.protobuf.Empty);
+  rpc PetsGet (PetsGetRequest) returns (PetsGetResponse);
 
 }
 
@@ -25,3 +25,8 @@ message PetsGetRequest {
 
 }
 
+message PetsGetResponse {
+    oneof response {
+        google.protobuf.Empty empty_200 = 1;
+    }
+}

samples/config/petstore/protobuf-schema-config/models/data.proto

@@ -56,6 +56,16 @@ message Dog {
 
 }
 
+message Error {
+
+  // Error code.
+  int32 code = 1;
+
+  // Detailed error message.
+  string message = 2;
+
+}
+
 message Order {
 
   int64 id = 1;

samples/config/petstore/protobuf-schema/.openapi-generator/FILES

@@ -3,6 +3,7 @@ models/api_response.proto
 models/cat.proto
 models/category.proto
 models/dog.proto
+models/error.proto
 models/order.proto
 models/other_test.proto
 models/pet.proto

samples/config/petstore/protobuf-schema/models/error.proto

@@ -0,0 +1,25 @@
+/*
+  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;
+
+
+message Error {
+
+  // Error code.
+  int32 code = 3059181;
+
+  // Detailed error message.
+  string message = 418054152;
+
+}
+

samples/config/petstore/protobuf-schema/services/default_service.proto

@@ -17,9 +17,9 @@ import public "models/pets_get_request.proto";
 import public "models/pets_post_request.proto";
 
 service DefaultService {
-  rpc PetsGet (PetsGetRequest) returns (google.protobuf.Empty);
+  rpc PetsGet (PetsGetRequest) returns (PetsGetResponse);
 
-  rpc PetsPost (PetsPostRequest) returns (google.protobuf.Empty);
+  rpc PetsPost (PetsPostRequest) returns (PetsPostResponse);
 
 }
 
@@ -28,8 +28,18 @@ message PetsGetRequest {
 
 }
 
+message PetsGetResponse {
+    oneof response {
+        google.protobuf.Empty empty_200 = 1;
+    }
+}
 message PetsPostRequest {
   PetsPostRequest pets_post_request = 1;
 
 }
 
+message PetsPostResponse {
+    oneof response {
+        google.protobuf.Empty empty_200 = 1;
+    }
+}