Include feedback from review.

src/node/hooks/express/openapi.js

@@ -16,6 +16,8 @@
 
 const OpenAPIBackend = require('openapi-backend').default;
 const IncomingForm = require('formidable').IncomingForm;
+const firstValues = require('formidable').firstValues;
+
 const cloneDeep = require('lodash.clonedeep');
 const createHTTPError = require('http-errors');
 
@@ -594,17 +596,14 @@ exports.expressPreSession = async (hookName, {app}) => {
 
           // read form data if method was POST
           let formData = {};
+          let formDataSingle;
           if (c.request.method === 'post') {
             const form = new IncomingForm();
             formData = (await form.parse(req))[0];
-            for (const k of Object.keys(formData)) {
-              if (formData[k] instanceof Array) {
-                formData[k] = formData[k][0];
-              }
-            }
+            formDataSingle = firstValues(form, formData);
           }
 
-          const fields = Object.assign({}, header, params, query, formData);
+          const fields = Object.assign({}, header, params, query, formDataSingle);
 
           if (logger.isDebugEnabled()) {
             logger.debug(`REQUEST, v${version}:${funcName}, ${JSON.stringify(fields)}`);