feat(protobuf-generator): Improve protobuf generation

* Improve management of inheritance
* Improve management of discriminator
* Allow to separate inline enums in external files
* Add unit test

Author: Anthony TODISCO

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

@@ -88,6 +88,10 @@ public MappedModel(String mappingName, String modelName, boolean explicitMapping
             this.explicitMapping = explicitMapping;
         }
 
+        public boolean isExplicitMapping() {
+            return explicitMapping;
+        }
+
         public MappedModel(String mappingName, String modelName) {
             this(mappingName, modelName, false);
         }

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

@@ -37,6 +37,7 @@ import public "{{{.}}}.proto";
   {{#vendorExtensions.x-protobuf-type}}{{{.}}} {{/vendorExtensions.x-protobuf-type}}{{{vendorExtensions.x-protobuf-data-type}}} {{{name}}} = {{vendorExtensions.x-protobuf-index}}{{#vendorExtensions.x-protobuf-packed}} [packed=true]{{/vendorExtensions.x-protobuf-packed}}{{#vendorExtensions.x-protobuf-json-name}} [json_name="{{vendorExtensions.x-protobuf-json-name}}"]{{/vendorExtensions.x-protobuf-json-name}};
   {{/isEnum}}
   {{#isEnum}}
+  {{^vendorExtensions.x-protobuf-enum-reference-import}}
   enum {{enumName}} {
     {{#allowableValues}}
     {{#enumVars}}
@@ -45,6 +46,7 @@ import public "{{{.}}}.proto";
     {{/allowableValues}}
   }
 
+  {{/vendorExtensions.x-protobuf-enum-reference-import}}
   {{enumName}} {{name}} = {{vendorExtensions.x-protobuf-index}};
   {{/isEnum}}
 

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

@@ -80,7 +80,7 @@ components:
         - $ref: '#/components/schemas/Lizard'
       discriminator:
         propertyName: petType
-        # per https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#discriminatorObject
+        # per https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#discriminator-object
         # this discriminator must be included to use it as a hint to pick a schema
     MyPetsNoDisc:
       oneOf:

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

@@ -18,8 +18,6 @@ message Animal {
 
   string pet_type = 482112090;
 
-  string bark = 3016376;
-
   string name = 3373707;
 
   string fur_color = 478695002;
@@ -28,4 +26,6 @@ message Animal {
 
   CareDetails care_details = 176721135;
 
+  string bark = 3016376;
+
 }

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

@@ -0,0 +1,32 @@
+openapi: 3.0.0
+info:
+  title: Enum extraction test
+  version: '2.0'
+paths: {}
+components:
+  schemas:
+    SeparatedEnum:
+      type: string
+      enum:
+        - VALUE1
+        - VALUE2
+    ModelWithEnums:
+      properties:
+        referenceEnumProperty:
+          $ref: "#/components/schemas/SeparatedEnum"
+        inlineEnumProperty:
+          type: string
+          enum:
+            - VALUE2
+            - VALUE3
+            - VALUE4
+    AllOfModelWithEnums:
+      allOf:
+        - $ref: "#/components/schemas/ModelWithEnums"
+        - type: object
+          properties:
+            anotherInlineEnumProperty:
+              type: string
+              enum:
+                - VALUE5
+                - VALUE6

modules/openapi-generator/src/test/resources/3_0/protobuf-schema/animal.proto

@@ -0,0 +1,89 @@
+openapi: 3.0.0
+info:
+  title: Model Import Test
+  version: 1.0.0
+paths: {}
+components:
+  schemas:
+    A:
+      type: object
+      description: Base model A that will be referenced multiple times
+      properties:
+        id:
+          type: string
+        value:
+          type: string
+      required:
+        - id
+    
+    SubModel:
+      type: object
+      description: SubModel that uses model A
+      allOf:
+        - $ref: '#/components/schemas/ExtensibleModel'
+        - type: object
+          properties:
+            subField:
+              type: string
+            aReference:
+              $ref: '#/components/schemas/A'
+          required:
+            - subField
+    
+    Model:
+      type: object
+      description: Main model that uses A directly and via SubModel
+      properties:
+        name:
+          type: string
+        directA:
+          $ref: '#/components/schemas/A'
+        nestedSubModel:
+          $ref: '#/components/schemas/SubModel'
+      required:
+        - name
+    
+    ExtensibleModel:
+      type: object
+      description: Extensible model with discriminator that uses model A
+      discriminator:
+        propertyName: type
+        mapping:
+          child1: '#/components/schemas/ChildModel_1'
+          child2: '#/components/schemas/ChildModel_2'
+      properties:
+        type:
+          type: string
+        extensibleA:
+          $ref: '#/components/schemas/A'
+      required:
+        - type
+    
+    ChildModel_1:
+      allOf:
+        - $ref: '#/components/schemas/ExtensibleModel'
+        - type: object
+          properties:
+            childSpecificField:
+              type: string
+            childA:
+              $ref: '#/components/schemas/A'
+    ChildModel_2:
+      allOf:
+        - $ref: '#/components/schemas/SubExtensibleModel'
+        - type: object
+          properties:
+            anotherChildSpecificField:
+              type: integer
+            directA:
+              $ref: '#/components/schemas/A'
+    
+    SubExtensibleModel:
+      allOf:
+        - $ref: '#/components/schemas/ExtensibleModel'
+        - type: object
+          properties:
+            aSubExtensibleField:
+              type: boolean
+            subDirectA:
+              $ref: '#/components/schemas/A'

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

@@ -26,4 +26,6 @@ message Pet {
 
   bool loves_rocks = 465093427;
 
+  bool has_legs = 140596906;
+
 }