Fix get headers when null (#79)

* Update index.js

* bump version

Author: xinghengwang

lib/index.js

@@ -57,6 +57,15 @@ var defaultIdentifyUser = function (req, res) {
   return undefined;
 };
 
+var getReqHeaders = function (req) {
+  if (req.headers) {
+    return req.headers;
+  } else if (req.getHeaders) {
+    return req.getHeaders() || {};
+  }
+  return {};
+}
+
 /**
  * @typedef {Object} MoesifOptions
  * @property {string} applicationId
@@ -341,9 +350,11 @@ function makeMoesifMiddleware(options) {
     var rawReqDataFromEventEmitter;
     var dataEventTracked = false;
 
+    var reqHeaders = getReqHeaders(req);
+
     // determines if the request is or isn't a multipart/form-data "file" type
-    function isMultiPartUpload(request) {
-      const contentTypeHeader = request.headers['content-type'];
+    function isMultiPartUpload() {
+      const contentTypeHeader = reqHeaders && reqHeaders['content-type'];
       if (!contentTypeHeader) {
         return false;
       } else if (contentTypeHeader.indexOf('multipart/form-data') >= 0) {
@@ -352,15 +363,15 @@ function makeMoesifMiddleware(options) {
       return false;
     }
 
-    var multiPartUpload = isMultiPartUpload(req);
+    var multiPartUpload = isMultiPartUpload();
 
     if (
       options.logBody &&
       !req.body &&
-      req.headers &&
-      req.headers['content-type'] &&
-      req.headers['content-length'] &&
-      parseInt(req.headers['content-length']) > 0 &&
+      reqHeaders &&
+      reqHeaders['content-type'] &&
+      reqHeaders['content-length'] &&
+      parseInt(reqHeaders['content-length']) > 0 &&
       //if the request is "multipart/form-data" file type, we do not attempt to capture the body, otherwise we capture it
       !multiPartUpload
     ) {
@@ -467,7 +478,7 @@ function makeMoesifMiddleware(options) {
     var addTxIdToResponseStartTime = Date.now();
     let disableTransactionId = options.disableTransactionId ? options.disableTransactionId : false;
     if (!disableTransactionId) {
-      let txId = req.headers[TRANSACTION_ID_HEADER] || uuid4();
+      let txId = reqHeaders[TRANSACTION_ID_HEADER] || uuid4();
       // Use setHeader() instead of set() so it works with plain http-module and Express
       res.setHeader(TRANSACTION_ID_HEADER, txId);
     }

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "moesif-nodejs",
-  "version": "3.5.1",
+  "version": "3.5.2",
   "description": "Monitoring agent to log API calls to Moesif for deep API analytics",
   "main": "lib/index.js",
   "typings": "dist/index.d.ts",