From e3744463a153893d84eef5600b2f792a6e9d251b Mon Sep 17 00:00:00 2001
From: Steven Chim <655241+chimurai@users.noreply.github.com>
Date: Sat, 7 Feb 2026 22:01:47 +0000
Subject: [PATCH] test(types.spec.ts): add type check when req or res are 'any'

---
 test/types.spec.ts | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/test/types.spec.ts b/test/types.spec.ts
index 6f306f9b..5c69c05a 100644
--- a/test/types.spec.ts
+++ b/test/types.spec.ts
@@ -182,6 +182,11 @@ describe('http-proxy-middleware TypeScript Types', () => {
             error(error, req, res, target) {
               req.params;
 
+              // @ts-expect-error: should error when request is typed as `any`
+              req.unknownProperty;
+              // @ts-expect-error: should error when response is typed as `any`
+              res.unknownProperty;
+
               // https://www.typescriptlang.org/docs/handbook/2/narrowing.html
               if (res instanceof http.ServerResponse) {
                 res.status(200).send('OK');
@@ -345,6 +350,11 @@ describe('http-proxy-middleware TypeScript Types', () => {
           proxyRes: responseInterceptor(async (buffer, proxyRes, req, res) => {
             req.myRequestParams;
             res.myResponseParams;
+
+            // @ts-expect-error: should error when request is typed as `any`
+            req.unknownProperty;
+            // @ts-expect-error: should error when response is typed as `any`
+            res.unknownProperty;
             return buffer;
           }),
         },
@@ -371,6 +381,12 @@ describe('http-proxy-middleware TypeScript Types', () => {
           (proxyServer, options) => {
             proxyServer.on('proxyReq', (proxyReq, req, res, options) => {
               req.params;
+
+              // @ts-expect-error: should error when request is typed as `any`
+              req.unknownProperty;
+              // @ts-expect-error: should error when response is typed as `any`
+              res.unknownProperty;
+
               res.status(200).send('OK');
             });
           },
@@ -396,6 +412,12 @@ describe('http-proxy-middleware TypeScript Types', () => {
                 responseInterceptor(async (buffer, proxyRes, req, res) => {
                   req.params;
                   res.status(200).send('OK');
+
+                  // @ts-expect-error: should error when request is typed as `any`
+                  req.unknownProperty;
+                  // @ts-expect-error: should error when response is typed as `any`
+                  res.unknownProperty;
+
                   return buffer;
                 }),
               );