From 304664a9e9f14a610456302a31fc29a71b7f1554 Mon Sep 17 00:00:00 2001
From: Dorian Niemiec <dorian.niemiec@svrjs.org>
Date: Sun, 19 Jan 2025 11:31:45 +0100
Subject: [PATCH] fix: improved compatiblity with SVR.JS Cache mod on Node.js

---
 src/index.js | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/index.js b/src/index.js
index 9b21752..d86c8da 100644
--- a/src/index.js
+++ b/src/index.js
@@ -51,7 +51,8 @@ module.exports = (req, res, logFacilities, config, next) => {
     const originalWriteHead = res.writeHead.bind(res);
     const originalWrite = res.write.bind(res);
     const originalEnd = res.end.bind(res);
-    let writtenHeaders = res.getHeaders();
+    let checkedHeaders = res.getHeaders();
+    let writtenHeaders = {};
     let writtenStatusCode = 200;
     let writtenStatusCodeDescription = null;
     let headersSet = false;
@@ -60,36 +61,37 @@ module.exports = (req, res, logFacilities, config, next) => {
     const responseWriteCallbacks = [];
 
     res.setHeader = function (name, value) {
-      writtenHeaders[name.toLowerCase()] = value;
+      checkedHeaders[name.toLowerCase()] = value;
       return originalSetHeader(name, value);
     };
 
     res.removeHeader = function (name) {
-      delete writtenHeaders[name.toLowerCase()];
+      delete checkedHeaders[name.toLowerCase()];
       return originalRemoveHeader(name);
     };
 
     res.writeHead = function (statusCode, statusCodeDescription, headers) {
       const properHeaders = headers ? headers : statusCodeDescription;
       if (typeof properHeaders === "object" && properHeaders !== null) {
+        writtenHeaders = properHeaders;
         Object.keys(properHeaders).forEach((key) => {
-          writtenHeaders[key.toLowerCase()] = properHeaders[key];
+          checkedHeaders[key.toLowerCase()] = properHeaders[key];
         });
       }
       writtenStatusCode = statusCode;
       let intervene = false;
-      Object.keys(writtenHeaders).every((key) => {
-        if (typeof writtenHeaders[key] == "string") {
+      Object.keys(checkedHeaders).every((key) => {
+        if (typeof checkedHeaders[key] == "string") {
           securityResponse = transaction.addResponseHeader(
             key,
-            writtenHeaders[key]
+            checkedHeaders[key]
           );
           if (typeof securityResponse === "object") {
             intervene = true;
             return false;
           }
-        } else if (Array.isArray(writtenHeaders[key])) {
-          writtenHeaders[key].every((value) => {
+        } else if (Array.isArray(checkedHeaders[key])) {
+          checkedHeaders[key].every((value) => {
             securityResponse = transaction.addResponseHeader(key, value);
             if (typeof securityResponse === "object") {
               intervene = true;
@@ -145,18 +147,18 @@ module.exports = (req, res, logFacilities, config, next) => {
     res.end = function (chunk, encoding, callback) {
       if (!headersSet) {
         let intervene = false;
-        Object.keys(writtenHeaders).forEach((key) => {
-          if (typeof writtenHeaders[key] == "string") {
+        Object.keys(checkedHeaders).forEach((key) => {
+          if (typeof checkedHeaders[key] == "string") {
             securityResponse = transaction.addResponseHeader(
               key,
-              writtenHeaders[key]
+              checkedHeaders[key]
             );
             if (typeof securityResponse === "object") {
               intervene = true;
               return;
             }
-          } else if (Array.isArray(writtenHeaders[key])) {
-            writtenHeaders[key].forEach((value) => {
+          } else if (Array.isArray(checkedHeaders[key])) {
+            checkedHeaders[key].forEach((value) => {
               securityResponse = transaction.addResponseHeader(key, value);
               if (typeof securityResponse === "object") {
                 intervene = true;
@@ -269,18 +271,18 @@ module.exports = (req, res, logFacilities, config, next) => {
       res.write = function (chunk, encoding, callback) {
         if (!headersSet) {
           let intervene = false;
-          Object.keys(writtenHeaders).every((key) => {
-            if (typeof writtenHeaders[key] == "string") {
+          Object.keys(checkedHeaders).every((key) => {
+            if (typeof checkedHeaders[key] == "string") {
               securityResponse = transaction.addResponseHeader(
                 key,
-                writtenHeaders[key]
+                checkedHeaders[key]
               );
               if (typeof securityResponse === "object") {
                 intervene = true;
                 return false;
               }
-            } else if (Array.isArray(writtenHeaders[key])) {
-              writtenHeaders[key].every((value) => {
+            } else if (Array.isArray(checkedHeaders[key])) {
+              checkedHeaders[key].every((value) => {
                 securityResponse = transaction.addResponseHeader(key, value);
                 if (typeof securityResponse === "object") {
                   intervene = true;