[PHP] $httpBody Array encode is missing

Description

I just updated from 2.0 to 3.0, and everything works fine on my Backend.
The functions are up to date and reflect what i want.

So know i was going to check if the client also work.
It compiles like the 2.0 version, some minor naming changes, but its fine.

Normal endpoints with an object work great.

Now to the problem, my api expects an array in the body, not an object.

This worked in the old client, but does not work in the new version. The SwaggerUI reflects the array and i can query from there.

Swagger-codegen version

latest docker version

Command line used for generation

generate --input-spec ${URL} --lang php -o /dest -c /configs/php.config.json

Steps to reproduce

Normal client creation from the swaggerjson file.

Suggest a fix/enhancement

In the old version it looked like this:

    /**
     * Create request for operation 'batchStartnodeRelationEndnodePost'
     *
     * @param  \Swagger\Client\Model\BatchNodesRelationDto $batch_nodes_relation_dto (required)
     *
     * @throws \InvalidArgumentException
     * @return \GuzzleHttp\Psr7\Request
     */
    protected function batchStartnodeRelationEndnodePostRequest($batch_nodes_relation_dto)
    {
        // verify the required parameter 'batch_nodes_relation_dto' is set
        if ($batch_nodes_relation_dto === null || (is_array($batch_nodes_relation_dto) && count($batch_nodes_relation_dto) === 0)) {
            throw new \InvalidArgumentException(
                'Missing the required parameter $batch_nodes_relation_dto when calling batchStartnodeRelationEndnodePost'
            );
        }

        $resourcePath = '/batch/startnode-relation-endnode';
        $formParams = [];
        $queryParams = [];
        $headerParams = [];
        $httpBody = '';
        $multipart = false;



        // body params
        $_tempBody = null;
        if (isset($batch_nodes_relation_dto)) {
            $_tempBody = $batch_nodes_relation_dto;
        }

        if ($multipart) {
            $headers = $this->headerSelector->selectHeadersForMultipart(
                ['application/json']
            );
        } else {
            $headers = $this->headerSelector->selectHeaders(
                ['application/json'],
                ['application/json']
            );
        }

        // for model (json/xml)
        if (isset($_tempBody)) {
            // $_tempBody is the method argument, if present
            $httpBody = $_tempBody;
            
            if($headers['Content-Type'] === 'application/json') {
                // \stdClass has no __toString(), so we should encode it manually
                if ($httpBody instanceof \stdClass) {
                    $httpBody = \GuzzleHttp\json_encode($httpBody);
                }
                // array has no __toString(), so we should encode it manually
                if(is_array($httpBody)) {
                    $httpBody = \GuzzleHttp\json_encode(ObjectSerializer::sanitizeForSerialization($httpBody));
                }
            }
        } elseif (count($formParams) > 0) {
            if ($multipart) {
                $multipartContents = [];
                foreach ($formParams as $formParamName => $formParamValue) {
                    $multipartContents[] = [
                        'name' => $formParamName,
                        'contents' => $formParamValue
                    ];
                }
                // for HTTP post (form)
                $httpBody = new MultipartStream($multipartContents);

            } elseif ($headers['Content-Type'] === 'application/json') {
                $httpBody = \GuzzleHttp\json_encode($formParams);

            } else {
                // for HTTP post (form)
                $httpBody = \GuzzleHttp\Psr7\build_query($formParams);
            }
        }


        $defaultHeaders = [];
        if ($this->config->getUserAgent()) {
            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
        }

        $headers = array_merge(
            $defaultHeaders,
            $headerParams,
            $headers
        );

        $query = \GuzzleHttp\Psr7\build_query($queryParams);
        return new Request(
            'POST',
            $this->config->getHost() . $resourcePath . ($query ? "?{$query}" : ''),
            $headers,
            $httpBody
        );
    }

New Version looks like this:

    /**
     * Create request for operation 'batchControllerPostBatchData'
     *
     * @param  \Swagger\Client\Model\BatchPostDto[] $body A array of data to input (required)
     * @param  string $mode Specify if you need to upsert the input (optional)
     *
     * @throws \InvalidArgumentException
     * @return \GuzzleHttp\Psr7\Request
     */
    protected function batchControllerPostBatchDataRequest($body, $mode = null)
    {
        // verify the required parameter 'body' is set
        if ($body === null || (is_array($body) && count($body) === 0)) {
            throw new \InvalidArgumentException(
                'Missing the required parameter $body when calling batchControllerPostBatchData'
            );
        }

        $resourcePath = '/batch';
        $formParams = [];
        $queryParams = [];
        $headerParams = [];
        $httpBody = '';
        $multipart = false;

        // query params
        if ($mode !== null) {
            $queryParams['mode'] = ObjectSerializer::toQueryValue($mode);
        }


        // body params
        $_tempBody = null;
        if (isset($body)) {
            $_tempBody = $body;
        }

        if ($multipart) {
            $headers = $this->headerSelector->selectHeadersForMultipart(
                ['application/json']
            );
        } else {
            $headers = $this->headerSelector->selectHeaders(
                ['application/json'],
                ['application/json']
            );
        }

        // for model (json/xml)
        if (isset($_tempBody)) {
            // $_tempBody is the method argument, if present
            $httpBody = $_tempBody;
            // \stdClass has no __toString(), so we should encode it manually
            if ($httpBody instanceof \stdClass && $headers['Content-Type'] === 'application/json') {
                $httpBody = \GuzzleHttp\json_encode($httpBody);
            }
        } elseif (count($formParams) > 0) {
            if ($multipart) {
                $multipartContents = [];
                foreach ($formParams as $formParamName => $formParamValue) {
                    $multipartContents[] = [
                        'name' => $formParamName,
                        'contents' => $formParamValue
                    ];
                }
                // for HTTP post (form)
                $httpBody = new MultipartStream($multipartContents);

            } elseif ($headers['Content-Type'] === 'application/json') {
                $httpBody = \GuzzleHttp\json_encode($formParams);

            } else {
                // for HTTP post (form)
                $httpBody = \GuzzleHttp\Psr7\build_query($formParams);
            }
        }


        $defaultHeaders = [];
        if ($this->config->getUserAgent()) {
            $defaultHeaders['User-Agent'] = $this->config->getUserAgent();
        }

        $headers = array_merge(
            $defaultHeaders,
            $headerParams,
            $headers
        );

        $query = \GuzzleHttp\Psr7\build_query($queryParams);
        return new Request(
            'POST',
            $this->config->getHost() . $resourcePath . ($query ? "?{$query}" : ''),
            $headers,
            $httpBody
        );
    }

The functions changed a bit, but the important part is the is_array that got lost in the new version.

Start by running the documented generate --input-spec ${URL} --lang php command and inspect the generated batchControllerPostBatchDataRequest method alongside the old example. Trace how an array body is handled for application/json; done means generated PHP clients serialize array request bodies correctly, with coverage or a reproducible check for the batch endpoint.