[GO][SERVER] Implement response code (#7397)

* Feature(template) add response with status code generation

* Generate Samples

* update samples

Co-authored-by: William Cheng <wing328hk@gmail.com>

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

@@ -136,8 +136,6 @@ public class GoServerCodegen extends AbstractGoCodegen {
     @Override
     public void processOpts() {
         super.processOpts();
-
-
         /*
          * Additional Properties.  These values can be passed to the templates and
          * are available in models, apis, and supporting files
@@ -201,6 +199,8 @@ public class GoServerCodegen extends AbstractGoCodegen {
         supportingFiles.add(new SupportingFile("go.mod.mustache", "", "go.mod"));
         supportingFiles.add(new SupportingFile("routers.mustache", sourceFolder, "routers.go"));
         supportingFiles.add(new SupportingFile("logger.mustache", sourceFolder, "logger.go"));
+        supportingFiles.add(new SupportingFile("impl.mustache",sourceFolder, "impl.go"));
+        supportingFiles.add(new SupportingFile("helpers.mustache", sourceFolder, "helpers.go"));
         supportingFiles.add(new SupportingFile("api.mustache", sourceFolder, "api.go"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md")
                 .doNotOverwrite());

modules/openapi-generator/src/main/resources/go-server/api.mustache

@@ -7,6 +7,7 @@ import (
 	"{{import}}"{{/imports}}{{/apis}}{{/apiInfo}}
 )
 
+
 {{#apiInfo}}{{#apis}}
 // {{classname}}Router defines the required methods for binding the api requests to a responses for the {{classname}}
 // The {{classname}}Router implementation should parse necessary information from the http request, 
@@ -21,5 +22,5 @@ type {{classname}}Router interface { {{#operations}}{{#operation}}
 // while the service implementation can ignored with the .openapi-generator-ignore file 
 // and updated with the logic required for the API.
 type {{classname}}Servicer interface { {{#operations}}{{#operation}}
-	{{operationId}}(context.Context{{#allParams}}, {{dataType}}{{/allParams}}) (interface{}, error){{/operation}}{{/operations}}
+	{{operationId}}(context.Context{{#allParams}}, {{dataType}}{{/allParams}}) (ImplResponse, error){{/operation}}{{/operations}}
 }{{/apis}}{{/apiInfo}}

modules/openapi-generator/src/main/resources/go-server/controller-api.mustache

@@ -93,10 +93,12 @@ func (c *{{classname}}Controller) {{nickname}}(w http.ResponseWriter, r *http.Re
 	}
 	{{/isBodyParam}}{{/allParams}}
 	result, err := c.service.{{nickname}}(r.Context(){{#allParams}}, {{#isBodyParam}}*{{/isBodyParam}}{{paramName}}{{/allParams}})
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }{{/operation}}{{/operations}}

modules/openapi-generator/src/main/resources/go-server/helpers.mustache

@@ -0,0 +1,8 @@
+{{>partial_header}}
+package {{packageName}}
+
+//Response return a ImplResponse struct filled
+func Response(code int, body interface{}) ImplResponse {
+	return ImplResponse{Code: code, Body: body}
+}
+

modules/openapi-generator/src/main/resources/go-server/impl.mustache

@@ -0,0 +1,8 @@
+{{>partial_header}}
+package {{packageName}}
+
+//Implementation response defines an error code with the associated body
+type ImplResponse struct {
+	Code int
+	Body interface{}
+}

modules/openapi-generator/src/main/resources/go-server/service.mustache

@@ -3,6 +3,7 @@ package {{packageName}}
 
 import (
 	"context"
+	"net/http"
 	"errors"{{#imports}}
 	"{{import}}"{{/imports}}
 )
@@ -19,8 +20,22 @@ func New{{classname}}Service() {{classname}}Servicer {
 }{{#operations}}{{#operation}}
 
 // {{nickname}} - {{summary}}
-func (s *{{classname}}Service) {{nickname}}(ctx context.Context{{#allParams}}, {{paramName}} {{dataType}}{{/allParams}}) (interface{}, error) {
+func (s *{{classname}}Service) {{nickname}}(ctx context.Context{{#allParams}}, {{paramName}} {{dataType}}{{/allParams}}) (ImplResponse, error) {
 	// TODO - update {{nickname}} with the required logic for this service method.
 	// Add {{classFilename}}_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method '{{nickname}}' not implemented")
+
+{{#responses}}
+{{#dataType}}
+    //TODO: Uncomment the next line to return response Response({{code}}, {{dataType}}{}) or use other options such as http.Ok ...
+    //return Response({{code}}, {{dataType}}{}), nil
+
+{{/dataType}}
+{{^dataType}}
+    //TODO: Uncomment the next line to return response Response({{code}}, {{dataType}}{}) or use other options such as http.Ok ...
+	//return Response({{code}}, nil),nil
+
+{{/dataType}}
+{{/responses}}
+    return Response(http.StatusNotImplemented, nil), errors.New("{{nickname}} method not implemented")
 }{{/operation}}{{/operations}}
+

samples/server/petstore/go-api-server/.openapi-generator/FILES

@@ -9,6 +9,8 @@ go/api_store.go
 go/api_store_service.go
 go/api_user.go
 go/api_user_service.go
+go/helpers.go
+go/impl.go
 go/logger.go
 go/model_api_response.go
 go/model_category.go

samples/server/petstore/go-api-server/go/api.go

@@ -16,6 +16,7 @@ import (
 )
 
 
+
 // PetApiRouter defines the required methods for binding the api requests to a responses for the PetApi
 // The PetApiRouter implementation should parse necessary information from the http request, 
 // pass the data to a PetApiServicer to perform the required actions, then write the service results to the http response.
@@ -58,14 +59,14 @@ type UserApiRouter interface {
 // while the service implementation can ignored with the .openapi-generator-ignore file 
 // and updated with the logic required for the API.
 type PetApiServicer interface { 
-	AddPet(context.Context, Pet) (interface{}, error)
+	AddPet(context.Context, Pet) (ImplResponse, error)
-	DeletePet(context.Context, int64, string) (interface{}, error)
+	DeletePet(context.Context, int64, string) (ImplResponse, error)
-	FindPetsByStatus(context.Context, []string) (interface{}, error)
+	FindPetsByStatus(context.Context, []string) (ImplResponse, error)
-	FindPetsByTags(context.Context, []string) (interface{}, error)
+	FindPetsByTags(context.Context, []string) (ImplResponse, error)
-	GetPetById(context.Context, int64) (interface{}, error)
+	GetPetById(context.Context, int64) (ImplResponse, error)
-	UpdatePet(context.Context, Pet) (interface{}, error)
+	UpdatePet(context.Context, Pet) (ImplResponse, error)
-	UpdatePetWithForm(context.Context, int64, string, string) (interface{}, error)
+	UpdatePetWithForm(context.Context, int64, string, string) (ImplResponse, error)
-	UploadFile(context.Context, int64, string, *os.File) (interface{}, error)
+	UploadFile(context.Context, int64, string, *os.File) (ImplResponse, error)
 }
 
 
@@ -74,10 +75,10 @@ type PetApiServicer interface {
 // while the service implementation can ignored with the .openapi-generator-ignore file 
 // and updated with the logic required for the API.
 type StoreApiServicer interface { 
-	DeleteOrder(context.Context, string) (interface{}, error)
+	DeleteOrder(context.Context, string) (ImplResponse, error)
-	GetInventory(context.Context) (interface{}, error)
+	GetInventory(context.Context) (ImplResponse, error)
-	GetOrderById(context.Context, int64) (interface{}, error)
+	GetOrderById(context.Context, int64) (ImplResponse, error)
-	PlaceOrder(context.Context, Order) (interface{}, error)
+	PlaceOrder(context.Context, Order) (ImplResponse, error)
 }
 
 
@@ -86,12 +87,12 @@ type StoreApiServicer interface {
 // while the service implementation can ignored with the .openapi-generator-ignore file 
 // and updated with the logic required for the API.
 type UserApiServicer interface { 
-	CreateUser(context.Context, User) (interface{}, error)
+	CreateUser(context.Context, User) (ImplResponse, error)
-	CreateUsersWithArrayInput(context.Context, []User) (interface{}, error)
+	CreateUsersWithArrayInput(context.Context, []User) (ImplResponse, error)
-	CreateUsersWithListInput(context.Context, []User) (interface{}, error)
+	CreateUsersWithListInput(context.Context, []User) (ImplResponse, error)
-	DeleteUser(context.Context, string) (interface{}, error)
+	DeleteUser(context.Context, string) (ImplResponse, error)
-	GetUserByName(context.Context, string) (interface{}, error)
+	GetUserByName(context.Context, string) (ImplResponse, error)
-	LoginUser(context.Context, string, string) (interface{}, error)
+	LoginUser(context.Context, string, string) (ImplResponse, error)
-	LogoutUser(context.Context) (interface{}, error)
+	LogoutUser(context.Context) (ImplResponse, error)
-	UpdateUser(context.Context, string, User) (interface{}, error)
+	UpdateUser(context.Context, string, User) (ImplResponse, error)
 }

samples/server/petstore/go-api-server/go/api_pet.go

@@ -90,12 +90,14 @@ func (c *PetApiController) AddPet(w http.ResponseWriter, r *http.Request) {
 	}
 	
 	result, err := c.service.AddPet(r.Context(), *pet)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // DeletePet - Deletes a pet
@@ -108,12 +110,14 @@ func (c *PetApiController) DeletePet(w http.ResponseWriter, r *http.Request) {
 	}
 	apiKey := r.Header.Get("apiKey")
 	result, err := c.service.DeletePet(r.Context(), petId, apiKey)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // FindPetsByStatus - Finds Pets by status
@@ -121,12 +125,14 @@ func (c *PetApiController) FindPetsByStatus(w http.ResponseWriter, r *http.Reque
 	query := r.URL.Query()
 	status := strings.Split(query.Get("status"), ",")
 	result, err := c.service.FindPetsByStatus(r.Context(), status)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // FindPetsByTags - Finds Pets by tags
@@ -134,12 +140,14 @@ func (c *PetApiController) FindPetsByTags(w http.ResponseWriter, r *http.Request
 	query := r.URL.Query()
 	tags := strings.Split(query.Get("tags"), ",")
 	result, err := c.service.FindPetsByTags(r.Context(), tags)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // GetPetById - Find pet by ID
@@ -151,12 +159,14 @@ func (c *PetApiController) GetPetById(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	result, err := c.service.GetPetById(r.Context(), petId)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // UpdatePet - Update an existing pet
@@ -168,12 +178,14 @@ func (c *PetApiController) UpdatePet(w http.ResponseWriter, r *http.Request) {
 	}
 	
 	result, err := c.service.UpdatePet(r.Context(), *pet)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // UpdatePetWithForm - Updates a pet in the store with form data
@@ -193,12 +205,14 @@ func (c *PetApiController) UpdatePetWithForm(w http.ResponseWriter, r *http.Requ
 	name := r.FormValue("name")
 	status := r.FormValue("status")
 	result, err := c.service.UpdatePetWithForm(r.Context(), petId, name, status)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // UploadFile - uploads an image
@@ -223,10 +237,12 @@ func (c *PetApiController) UploadFile(w http.ResponseWriter, r *http.Request) {
 	}
 	
 	result, err := c.service.UploadFile(r.Context(), petId, additionalMetadata, file)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }

samples/server/petstore/go-api-server/go/api_pet_service.go

@@ -11,6 +11,7 @@ package petstoreserver
 
 import (
 	"context"
+	"net/http"
 	"errors"
 	"os"
 )
@@ -27,57 +28,114 @@ func NewPetApiService() PetApiServicer {
 }
 
 // AddPet - Add a new pet to the store
-func (s *PetApiService) AddPet(ctx context.Context, pet Pet) (interface{}, error) {
+func (s *PetApiService) AddPet(ctx context.Context, pet Pet) (ImplResponse, error) {
 	// TODO - update AddPet with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'AddPet' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+    //return Response(200, Pet{}), nil
+
+    //TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("AddPet method not implemented")
 }
 
 // DeletePet - Deletes a pet
-func (s *PetApiService) DeletePet(ctx context.Context, petId int64, apiKey string) (interface{}, error) {
+func (s *PetApiService) DeletePet(ctx context.Context, petId int64, apiKey string) (ImplResponse, error) {
 	// TODO - update DeletePet with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'DeletePet' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("DeletePet method not implemented")
 }
 
 // FindPetsByStatus - Finds Pets by status
-func (s *PetApiService) FindPetsByStatus(ctx context.Context, status []string) (interface{}, error) {
+func (s *PetApiService) FindPetsByStatus(ctx context.Context, status []string) (ImplResponse, error) {
 	// TODO - update FindPetsByStatus with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'FindPetsByStatus' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, []Pet{}) or use other options such as http.Ok ...
+    //return Response(200, []Pet{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("FindPetsByStatus method not implemented")
 }
 
 // FindPetsByTags - Finds Pets by tags
-func (s *PetApiService) FindPetsByTags(ctx context.Context, tags []string) (interface{}, error) {
+func (s *PetApiService) FindPetsByTags(ctx context.Context, tags []string) (ImplResponse, error) {
 	// TODO - update FindPetsByTags with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'FindPetsByTags' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, []Pet{}) or use other options such as http.Ok ...
+    //return Response(200, []Pet{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("FindPetsByTags method not implemented")
 }
 
 // GetPetById - Find pet by ID
-func (s *PetApiService) GetPetById(ctx context.Context, petId int64) (interface{}, error) {
+func (s *PetApiService) GetPetById(ctx context.Context, petId int64) (ImplResponse, error) {
 	// TODO - update GetPetById with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'GetPetById' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+    //return Response(200, Pet{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("GetPetById method not implemented")
 }
 
 // UpdatePet - Update an existing pet
-func (s *PetApiService) UpdatePet(ctx context.Context, pet Pet) (interface{}, error) {
+func (s *PetApiService) UpdatePet(ctx context.Context, pet Pet) (ImplResponse, error) {
 	// TODO - update UpdatePet with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'UpdatePet' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+    //return Response(200, Pet{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("UpdatePet method not implemented")
 }
 
 // UpdatePetWithForm - Updates a pet in the store with form data
-func (s *PetApiService) UpdatePetWithForm(ctx context.Context, petId int64, name string, status string) (interface{}, error) {
+func (s *PetApiService) UpdatePetWithForm(ctx context.Context, petId int64, name string, status string) (ImplResponse, error) {
 	// TODO - update UpdatePetWithForm with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'UpdatePetWithForm' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("UpdatePetWithForm method not implemented")
 }
 
 // UploadFile - uploads an image
-func (s *PetApiService) UploadFile(ctx context.Context, petId int64, additionalMetadata string, file *os.File) (interface{}, error) {
+func (s *PetApiService) UploadFile(ctx context.Context, petId int64, additionalMetadata string, file *os.File) (ImplResponse, error) {
 	// TODO - update UploadFile with the required logic for this service method.
 	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'UploadFile' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, ApiResponse{}) or use other options such as http.Ok ...
+    //return Response(200, ApiResponse{}), nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("UploadFile method not implemented")
 }
+

samples/server/petstore/go-api-server/go/api_store.go

@@ -62,23 +62,27 @@ func (c *StoreApiController) DeleteOrder(w http.ResponseWriter, r *http.Request)
 	params := mux.Vars(r)
 	orderId := params["orderId"]
 	result, err := c.service.DeleteOrder(r.Context(), orderId)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // GetInventory - Returns pet inventories by status
 func (c *StoreApiController) GetInventory(w http.ResponseWriter, r *http.Request) { 
 	result, err := c.service.GetInventory(r.Context())
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // GetOrderById - Find purchase order by ID
@@ -90,12 +94,14 @@ func (c *StoreApiController) GetOrderById(w http.ResponseWriter, r *http.Request
 		return
 	}
 	result, err := c.service.GetOrderById(r.Context(), orderId)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // PlaceOrder - Place an order for a pet
@@ -107,10 +113,12 @@ func (c *StoreApiController) PlaceOrder(w http.ResponseWriter, r *http.Request)
 	}
 	
 	result, err := c.service.PlaceOrder(r.Context(), *order)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }

samples/server/petstore/go-api-server/go/api_store_service.go

@@ -11,6 +11,7 @@ package petstoreserver
 
 import (
 	"context"
+	"net/http"
 	"errors"
 )
 
@@ -26,29 +27,58 @@ func NewStoreApiService() StoreApiServicer {
 }
 
 // DeleteOrder - Delete purchase order by ID
-func (s *StoreApiService) DeleteOrder(ctx context.Context, orderId string) (interface{}, error) {
+func (s *StoreApiService) DeleteOrder(ctx context.Context, orderId string) (ImplResponse, error) {
 	// TODO - update DeleteOrder with the required logic for this service method.
 	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'DeleteOrder' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("DeleteOrder method not implemented")
 }
 
 // GetInventory - Returns pet inventories by status
-func (s *StoreApiService) GetInventory(ctx context.Context) (interface{}, error) {
+func (s *StoreApiService) GetInventory(ctx context.Context) (ImplResponse, error) {
 	// TODO - update GetInventory with the required logic for this service method.
 	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'GetInventory' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, map[string]int32{}) or use other options such as http.Ok ...
+    //return Response(200, map[string]int32{}), nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("GetInventory method not implemented")
 }
 
 // GetOrderById - Find purchase order by ID
-func (s *StoreApiService) GetOrderById(ctx context.Context, orderId int64) (interface{}, error) {
+func (s *StoreApiService) GetOrderById(ctx context.Context, orderId int64) (ImplResponse, error) {
 	// TODO - update GetOrderById with the required logic for this service method.
 	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'GetOrderById' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, Order{}) or use other options such as http.Ok ...
+    //return Response(200, Order{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("GetOrderById method not implemented")
 }
 
 // PlaceOrder - Place an order for a pet
-func (s *StoreApiService) PlaceOrder(ctx context.Context, order Order) (interface{}, error) {
+func (s *StoreApiService) PlaceOrder(ctx context.Context, order Order) (ImplResponse, error) {
 	// TODO - update PlaceOrder with the required logic for this service method.
 	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'PlaceOrder' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, Order{}) or use other options such as http.Ok ...
+    //return Response(200, Order{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("PlaceOrder method not implemented")
 }
+

samples/server/petstore/go-api-server/go/api_user.go

@@ -90,12 +90,14 @@ func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
 	}
 	
 	result, err := c.service.CreateUser(r.Context(), *user)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // CreateUsersWithArrayInput - Creates list of users with given input array
@@ -107,12 +109,14 @@ func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *
 	}
 	
 	result, err := c.service.CreateUsersWithArrayInput(r.Context(), *user)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // CreateUsersWithListInput - Creates list of users with given input array
@@ -124,12 +128,14 @@ func (c *UserApiController) CreateUsersWithListInput(w http.ResponseWriter, r *h
 	}
 	
 	result, err := c.service.CreateUsersWithListInput(r.Context(), *user)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // DeleteUser - Delete user
@@ -137,12 +143,14 @@ func (c *UserApiController) DeleteUser(w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
 	username := params["username"]
 	result, err := c.service.DeleteUser(r.Context(), username)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // GetUserByName - Get user by user name
@@ -150,12 +158,14 @@ func (c *UserApiController) GetUserByName(w http.ResponseWriter, r *http.Request
 	params := mux.Vars(r)
 	username := params["username"]
 	result, err := c.service.GetUserByName(r.Context(), username)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // LoginUser - Logs user into the system
@@ -164,23 +174,27 @@ func (c *UserApiController) LoginUser(w http.ResponseWriter, r *http.Request) {
 	username := query.Get("username")
 	password := query.Get("password")
 	result, err := c.service.LoginUser(r.Context(), username, password)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // LogoutUser - Logs out current logged in user session
 func (c *UserApiController) LogoutUser(w http.ResponseWriter, r *http.Request) { 
 	result, err := c.service.LogoutUser(r.Context())
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }
 
 // UpdateUser - Updated user
@@ -194,10 +208,12 @@ func (c *UserApiController) UpdateUser(w http.ResponseWriter, r *http.Request) {
 	}
 	
 	result, err := c.service.UpdateUser(r.Context(), username, *user)
+	//If an error occured, encode the error with the status code
 	if err != nil {
-		w.WriteHeader(500)
+		EncodeJSONResponse(err.Error(), &result.Code, w)
 		return
 	}
+	//If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, w)
 	
-	EncodeJSONResponse(result, nil, w)
 }

samples/server/petstore/go-api-server/go/api_user_service.go

@@ -11,6 +11,7 @@ package petstoreserver
 
 import (
 	"context"
+	"net/http"
 	"errors"
 )
 
@@ -26,57 +27,105 @@ func NewUserApiService() UserApiServicer {
 }
 
 // CreateUser - Create user
-func (s *UserApiService) CreateUser(ctx context.Context, user User) (interface{}, error) {
+func (s *UserApiService) CreateUser(ctx context.Context, user User) (ImplResponse, error) {
 	// TODO - update CreateUser with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'CreateUser' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("CreateUser method not implemented")
 }
 
 // CreateUsersWithArrayInput - Creates list of users with given input array
-func (s *UserApiService) CreateUsersWithArrayInput(ctx context.Context, user []User) (interface{}, error) {
+func (s *UserApiService) CreateUsersWithArrayInput(ctx context.Context, user []User) (ImplResponse, error) {
 	// TODO - update CreateUsersWithArrayInput with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'CreateUsersWithArrayInput' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("CreateUsersWithArrayInput method not implemented")
 }
 
 // CreateUsersWithListInput - Creates list of users with given input array
-func (s *UserApiService) CreateUsersWithListInput(ctx context.Context, user []User) (interface{}, error) {
+func (s *UserApiService) CreateUsersWithListInput(ctx context.Context, user []User) (ImplResponse, error) {
 	// TODO - update CreateUsersWithListInput with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'CreateUsersWithListInput' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("CreateUsersWithListInput method not implemented")
 }
 
 // DeleteUser - Delete user
-func (s *UserApiService) DeleteUser(ctx context.Context, username string) (interface{}, error) {
+func (s *UserApiService) DeleteUser(ctx context.Context, username string) (ImplResponse, error) {
 	// TODO - update DeleteUser with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'DeleteUser' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("DeleteUser method not implemented")
 }
 
 // GetUserByName - Get user by user name
-func (s *UserApiService) GetUserByName(ctx context.Context, username string) (interface{}, error) {
+func (s *UserApiService) GetUserByName(ctx context.Context, username string) (ImplResponse, error) {
 	// TODO - update GetUserByName with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'GetUserByName' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, User{}) or use other options such as http.Ok ...
+    //return Response(200, User{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("GetUserByName method not implemented")
 }
 
 // LoginUser - Logs user into the system
-func (s *UserApiService) LoginUser(ctx context.Context, username string, password string) (interface{}, error) {
+func (s *UserApiService) LoginUser(ctx context.Context, username string, password string) (ImplResponse, error) {
 	// TODO - update LoginUser with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'LoginUser' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(200, string{}) or use other options such as http.Ok ...
+    //return Response(200, string{}), nil
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("LoginUser method not implemented")
 }
 
 // LogoutUser - Logs out current logged in user session
-func (s *UserApiService) LogoutUser(ctx context.Context) (interface{}, error) {
+func (s *UserApiService) LogoutUser(ctx context.Context) (ImplResponse, error) {
 	// TODO - update LogoutUser with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'LogoutUser' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("LogoutUser method not implemented")
 }
 
 // UpdateUser - Updated user
-func (s *UserApiService) UpdateUser(ctx context.Context, username string, user User) (interface{}, error) {
+func (s *UserApiService) UpdateUser(ctx context.Context, username string, user User) (ImplResponse, error) {
 	// TODO - update UpdateUser with the required logic for this service method.
 	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
-	return nil, errors.New("service method 'UpdateUser' not implemented")
+
+    //TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+    //TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+    return Response(http.StatusNotImplemented, nil), errors.New("UpdateUser method not implemented")
 }
+

samples/server/petstore/go-api-server/go/helpers.go

@@ -0,0 +1,16 @@
+/*
+ * 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.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+//Response return a ImplResponse struct filled
+func Response(code int, body interface{}) ImplResponse {
+	return ImplResponse{Code: code, Body: body}
+}
+

samples/server/petstore/go-api-server/go/impl.go

@@ -0,0 +1,16 @@
+/*
+ * 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.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+//Implementation response defines an error code with the associated body
+type ImplResponse struct {
+	Code int
+	Body interface{}
+}