From d0115f14f66b06d6fef05d114fdf093991456a50 Mon Sep 17 00:00:00 2001
From: simov <simeonvelichkov@gmail.com>
Date: Mon, 8 Mar 2021 21:27:49 +0200
Subject: [PATCH] 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>
---
 doc/api/deprecations.md                    |  1 +
 doc/api/http.md                            | 18 ++++++++++++++++++
 lib/_http_outgoing.js                      | 19 +++++++++++++++++++
 test/parallel/test-http-mutable-headers.js | 15 ++++++++++++++-
 4 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/doc/api/deprecations.md b/doc/api/deprecations.md
index 769d15516d99b5..3f78df5646ebbe 100644
--- a/doc/api/deprecations.md
+++ b/doc/api/deprecations.md
@@ -1340,6 +1340,7 @@ The `http` module `OutgoingMessage.prototype._headers` and
 the public methods (e.g. `OutgoingMessage.prototype.getHeader()`,
 `OutgoingMessage.prototype.getHeaders()`,
 `OutgoingMessage.prototype.getHeaderNames()`,
+`OutgoingMessage.prototype.getRawHeaderNames()`,
 `OutgoingMessage.prototype.hasHeader()`,
 `OutgoingMessage.prototype.removeHeader()`,
 `OutgoingMessage.prototype.setHeader()`) for working with outgoing headers.
diff --git a/doc/api/http.md b/doc/api/http.md
index dc24ff05278541..a50bd445c17faa 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -756,6 +756,24 @@ const cookie = request.getHeader('Cookie');
 // 'cookie' is of type string[]
 ```
 
+### `request.getRawHeaderNames()`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Returns: {string[]}
+
+Returns an array containing the unique names of the current outgoing raw
+headers. Header names are returned with their exact casing being set.
+
+```js
+request.setHeader('Foo', 'bar');
+request.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);
+
+const headerNames = request.getRawHeaderNames();
+// headerNames === ['Foo', 'Set-Cookie']
+```
+
 ### `request.maxHeadersCount`
 
 * {number} **Default:** `2000`
diff --git a/lib/_http_outgoing.js b/lib/_http_outgoing.js
index 5173dc8e9e46ac..7736c31c4d41a8 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];
diff --git a/test/parallel/test-http-mutable-headers.js b/test/parallel/test-http-mutable-headers.js
index c9f63acf4433f4..755a4dd66159e8 100644
--- a/test/parallel/test-http-mutable-headers.js
+++ b/test/parallel/test-http-mutable-headers.js
@@ -108,6 +108,10 @@ const s = http.createServer(common.mustCall((req, res) => {
                              ['x-test-header', 'x-test-header2',
                               'set-cookie', 'x-test-array-header']);
 
+      assert.deepStrictEqual(res.getRawHeaderNames(),
+                             ['x-test-header', 'X-TEST-HEADER2',
+                              'set-cookie', 'x-test-array-header']);
+
       assert.strictEqual(res.hasHeader('x-test-header2'), true);
       assert.strictEqual(res.hasHeader('X-TEST-HEADER2'), true);
       assert.strictEqual(res.hasHeader('X-Test-Header2'), true);
@@ -171,7 +175,10 @@ function nextTest() {
 
   let bufferedResponse = '';
 
-  http.get({ port: s.address().port }, common.mustCall((response) => {
+  const req = http.get({
+    port: s.address().port,
+    headers: { 'X-foo': 'bar' }
+  }, common.mustCall((response) => {
     switch (test) {
       case 'headers':
         assert.strictEqual(response.statusCode, 201);
@@ -214,4 +221,10 @@ function nextTest() {
       common.mustCall(nextTest)();
     }));
   }));
+
+  assert.deepStrictEqual(req.getHeaderNames(),
+                         ['x-foo', 'host']);
+
+  assert.deepStrictEqual(req.getRawHeaderNames(),
+                         ['X-foo', 'Host']);
 }