http: add http.ClientRequest.getRawHeaderNames()

Fixes: https://github.com/nodejs/node/issues/37641

PR-URL: https://github.com/nodejs/node/pull/37660
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/_http_outgoing.js b/lib/_http_outgoing.js
index 5173dc8e9e4..7736c31c4d4 100644
--- a/lib/_http_outgoing.js
+++ b/lib/_http_outgoing.js
@@ -22,10 +22,12 @@
 'use strict';
 
 const {
+  Array,
   ArrayIsArray,
   ObjectCreate,
   ObjectDefineProperty,
   ObjectKeys,
+  ObjectValues,
   ObjectPrototypeHasOwnProperty,
   ObjectSetPrototypeOf,
   MathFloor,
@@ -588,6 +590,23 @@ OutgoingMessage.prototype.getHeaderNames = function getHeaderNames() {
 };
 
 
+// Returns an array of the names of the current outgoing raw headers.
+OutgoingMessage.prototype.getRawHeaderNames = function getRawHeaderNames() {
+  const headersMap = this[kOutHeaders];
+  if (headersMap === null) return [];
+
+  const values = ObjectValues(headersMap);
+  const headers = Array(values.length);
+  // Retain for(;;) loop for performance reasons
+  // Refs: https://github.com/nodejs/node/pull/30958
+  for (let i = 0, l = values.length; i < l; i++) {
+    headers[i] = values[i][0];
+  }
+
+  return headers;
+};
+
+
 // Returns a shallow copy of the current outgoing headers.
 OutgoingMessage.prototype.getHeaders = function getHeaders() {
   const headers = this[kOutHeaders];