[C++][Pistache] Compile error when nesting references (#16711) (#18586)

When components/schema/<object> reference other objects, validate() was
getting called on the referenced objects with no arguments. The return
value was void, but checked as if it was a boolean value.

bin/configs/cpp-pistache-server-cpp-pistache-nested-schema-refs.yaml

@@ -0,0 +1,7 @@
+generatorName: cpp-pistache-server
+outputDir: samples/server/petstore/cpp-pistache-nested-schema-refs
+inputSpec: modules/openapi-generator/src/test/resources/3_0/nested-schema-refs.yaml
+templateDir: modules/openapi-generator/src/main/resources/cpp-pistache-server
+additionalProperties:
+  useStructModel: "false"
+  addExternalLibs: "true"

modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache

@@ -61,7 +61,7 @@ bool {{classname}}::validate(std::stringstream& msg, const std::string& pathPref
         {{> model-validation-body }}
     }
     {{/hasValidation}}{{#required}}{{#isModel}}
-    if (!m_{{name}}.validate()) {
+    if (!m_{{name}}.validate(msg, _pathPrefix + ".{{nameInCamelCase}}")) {
         msg << _pathPrefix << ": {{name}} is invalid;";
         success = false;
     }{{/isModel}}{{/required}}{{/isArray}}{{/vars}}{{/isEnum}}{{#vendorExtensions.x-is-string-enum-container}}{{#anyOf}}{{#-first}}

modules/openapi-generator/src/test/resources/3_0/nested-schema-refs.yaml

@@ -0,0 +1,37 @@
+openapi: 3.0.0
+info:
+  version: 1.0.0
+  title: Test swagger file
+
+paths:
+  /pet:
+    get:
+      tags:
+        - store
+      operationId: getNestedObject
+      responses:
+        '200':
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/outerType'
+components:
+  schemas:
+    outerType:
+      type: object
+      required:
+        - middle
+      properties:
+        middle:
+          $ref: '#/components/schemas/middleType'
+    middleType:
+      type: object
+      required:
+        - inner
+      properties:
+        inner:
+          $ref: '#/components/schemas/innerType'
+    innerType:
+      type: string
+

samples/server/petstore/cpp-pistache-nested-schema-refs/.gitignore

@@ -0,0 +1,3 @@
+build/
+external/
+pistache/

samples/server/petstore/cpp-pistache-nested-schema-refs/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/server/petstore/cpp-pistache-nested-schema-refs/.openapi-generator/FILES

@@ -0,0 +1,14 @@
+CMakeLists.txt
+README.md
+api/ApiBase.h
+api/StoreApi.cpp
+api/StoreApi.h
+impl/StoreApiImpl.cpp
+impl/StoreApiImpl.h
+main-api-server.cpp
+model/Helpers.cpp
+model/Helpers.h
+model/MiddleType.cpp
+model/MiddleType.h
+model/OuterType.cpp
+model/OuterType.h

samples/server/petstore/cpp-pistache-nested-schema-refs/.openapi-generator/VERSION

@@ -0,0 +1 @@
+7.6.0-SNAPSHOT

samples/server/petstore/cpp-pistache-nested-schema-refs/CMakeLists.txt

@@ -0,0 +1,38 @@
+cmake_minimum_required (VERSION 3.2)
+
+project(api-server)
+
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17 -pg -g3" )
+
+include(ExternalProject)
+
+set(EXTERNAL_INSTALL_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/external)
+
+ExternalProject_Add(PISTACHE
+    GIT_REPOSITORY https://github.com/pistacheio/pistache.git
+    BUILD_IN_SOURCE true
+    INSTALL_COMMAND meson setup build --prefix=${EXTERNAL_INSTALL_LOCATION} --libdir=lib && meson install -C build
+)
+
+ExternalProject_Add(NLOHMANN
+    GIT_REPOSITORY https://github.com/nlohmann/json.git
+    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${EXTERNAL_INSTALL_LOCATION} -DJSON_BuildTests=OFF
+)
+
+include_directories(${EXTERNAL_INSTALL_LOCATION}/include)
+link_directories(${EXTERNAL_INSTALL_LOCATION}/lib)
+
+include_directories(model)
+include_directories(api)
+include_directories(impl)
+
+file(GLOB SRCS
+    ${CMAKE_CURRENT_SOURCE_DIR}/api/*.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/impl/*.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/model/*.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp
+)
+
+add_executable(${PROJECT_NAME} ${SRCS} )
+add_dependencies(${PROJECT_NAME} PISTACHE NLOHMANN)
+target_link_libraries(${PROJECT_NAME} pistache pthread)

samples/server/petstore/cpp-pistache-nested-schema-refs/README.md

@@ -0,0 +1,48 @@
+# REST API Server for Test swagger file
+
+## Overview
+This API Server was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.
+It uses the [Pistache](https://github.com/oktal/pistache) Framework.
+
+## Files organization
+The Pistache C++ REST server generator creates three folders:
+- `api`: This folder contains the handlers for each method specified in the OpenAPI definition. Every handler extracts
+the path and body parameters (if any) from the requests and tries to parse and possibly validate them.
+Once this step is completed, the main API class calls the corresponding abstract method that should be implemented
+by the developer (a basic implementation is provided under the `impl` folder)
+- `impl`: As written above, the implementation folder contains, for each API, the corresponding implementation class,
+which extends the main API class and implements the abstract methods.
+Every method receives the path and body parameters as constant reference variables and a reference to the response
+object, that should be filled with the right response and sent at the end of the method with the command:
+response.send(returnCode, responseBody, [mimeType])
+- `model`: This folder contains the corresponding class for every object schema found in the OpenAPI specification.
+
+The main folder contains also a file with a main that can be used to start the server.
+Of course, is you should customize this file based on your needs
+
+## Installation
+First of all, you need to download and install the libraries listed [here](#libraries-required).
+
+Once the libraries are installed, in order to compile and run the server please follow the steps below:
+```bash
+mkdir build
+cd build
+cmake ..
+make
+```
+
+Once compiled run the server:
+
+```bash
+cd build
+./api-server
+```
+
+## Libraries required
+- [pistache](http://pistache.io/quickstart)
+- [JSON for Modern C++](https://github.com/nlohmann/json/#integration): Please download the `json.hpp` file and
+put it under the model/nlohmann folder
+
+## Namespaces
+org.openapitools.server.api
+org.openapitools.server.model

samples/server/petstore/cpp-pistache-nested-schema-refs/api/ApiBase.h

@@ -0,0 +1,39 @@
+/**
+* Test swagger file
+* No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+/*
+ * ApiBase.h
+ *
+ * Generalization of the Api classes
+ */
+
+#ifndef ApiBase_H_
+#define ApiBase_H_
+
+#include <pistache/router.h>
+#include <memory>
+
+namespace org::openapitools::server::api
+{
+
+class ApiBase {
+public:
+    explicit ApiBase(const std::shared_ptr<Pistache::Rest::Router>& rtr) : router(rtr) {};
+    virtual ~ApiBase() = default;
+    virtual void init() = 0;
+
+protected:
+    const std::shared_ptr<Pistache::Rest::Router> router;
+};
+
+} // namespace org::openapitools::server::api
+
+#endif /* ApiBase_H_ */

samples/server/petstore/cpp-pistache-nested-schema-refs/api/StoreApi.cpp

@@ -0,0 +1,86 @@
+/**
+* Test swagger file
+* No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+
+#include "StoreApi.h"
+#include "Helpers.h"
+
+namespace org::openapitools::server::api
+{
+
+using namespace org::openapitools::server::helpers;
+using namespace org::openapitools::server::model;
+
+const std::string StoreApi::base = "";
+
+StoreApi::StoreApi(const std::shared_ptr<Pistache::Rest::Router>& rtr)
+    : ApiBase(rtr)
+{
+}
+
+void StoreApi::init() {
+    setupRoutes();
+}
+
+void StoreApi::setupRoutes() {
+    using namespace Pistache::Rest;
+
+    Routes::Get(*router, base + "/pet", Routes::bind(&StoreApi::get_nested_object_handler, this));
+
+    // Default handler, called when a route is not found
+    router->addCustomHandler(Routes::bind(&StoreApi::store_api_default_handler, this));
+}
+
+std::pair<Pistache::Http::Code, std::string> StoreApi::handleParsingException(const std::exception& ex) const noexcept
+{
+    try {
+        throw;
+    } catch (nlohmann::detail::exception &e) {
+        return std::make_pair(Pistache::Http::Code::Bad_Request, e.what());
+    } catch (org::openapitools::server::helpers::ValidationException &e) {
+        return std::make_pair(Pistache::Http::Code::Bad_Request, e.what());
+    } catch (std::exception &e) {
+        return std::make_pair(Pistache::Http::Code::Internal_Server_Error, e.what());
+    }
+}
+
+std::pair<Pistache::Http::Code, std::string> StoreApi::handleOperationException(const std::exception& ex) const noexcept
+{
+    return std::make_pair(Pistache::Http::Code::Internal_Server_Error, ex.what());
+}
+
+void StoreApi::get_nested_object_handler(const Pistache::Rest::Request &, Pistache::Http::ResponseWriter response) {
+    try {
+
+
+    try {
+        this->get_nested_object(response);
+    } catch (Pistache::Http::HttpError &e) {
+        response.send(static_cast<Pistache::Http::Code>(e.code()), e.what());
+        return;
+    } catch (std::exception &e) {
+        const std::pair<Pistache::Http::Code, std::string> errorInfo = this->handleOperationException(e);
+        response.send(errorInfo.first, errorInfo.second);
+        return;
+    }
+
+    } catch (std::exception &e) {
+        response.send(Pistache::Http::Code::Internal_Server_Error, e.what());
+    }
+
+}
+
+void StoreApi::store_api_default_handler(const Pistache::Rest::Request &, Pistache::Http::ResponseWriter response) {
+    response.send(Pistache::Http::Code::Not_Found, "The requested method does not exist");
+}
+
+} // namespace org::openapitools::server::api
+

samples/server/petstore/cpp-pistache-nested-schema-refs/api/StoreApi.h

@@ -0,0 +1,77 @@
+/**
+* Test swagger file
+* No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+/*
+ * StoreApi.h
+ *
+ * 
+ */
+
+#ifndef StoreApi_H_
+#define StoreApi_H_
+
+
+#include "ApiBase.h"
+
+#include <pistache/http.h>
+#include <pistache/router.h>
+#include <pistache/http_headers.h>
+
+#include <optional>
+#include <utility>
+
+#include "OuterType.h"
+
+namespace org::openapitools::server::api
+{
+
+class  StoreApi : public ApiBase {
+public:
+    explicit StoreApi(const std::shared_ptr<Pistache::Rest::Router>& rtr);
+    ~StoreApi() override = default;
+    void init() override;
+
+    static const std::string base;
+
+private:
+    void setupRoutes();
+
+    void get_nested_object_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
+    void store_api_default_handler(const Pistache::Rest::Request &request, Pistache::Http::ResponseWriter response);
+
+    /// <summary>
+    /// Helper function to handle unexpected Exceptions during Parameter parsing and validation.
+    /// May be overridden to return custom error formats. This is called inside a catch block.
+    /// Important: When overriding, do not call `throw ex;`, but instead use `throw;`.
+    /// </summary>
+    virtual std::pair<Pistache::Http::Code, std::string> handleParsingException(const std::exception& ex) const noexcept;
+
+    /// <summary>
+    /// Helper function to handle unexpected Exceptions during processing of the request in handler functions.
+    /// May be overridden to return custom error formats. This is called inside a catch block.
+    /// Important: When overriding, do not call `throw ex;`, but instead use `throw;`.
+    /// </summary>
+    virtual std::pair<Pistache::Http::Code, std::string> handleOperationException(const std::exception& ex) const noexcept;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <remarks>
+    /// 
+    /// </remarks>
+    virtual void get_nested_object(Pistache::Http::ResponseWriter &response) = 0;
+
+};
+
+} // namespace org::openapitools::server::api
+
+#endif /* StoreApi_H_ */
+