refactor(#1136): replace `http-proxy` w/ `httpxy` by SukkaW · Pull Request #1160 · chimurai/http-proxy-middleware

SukkaW · 2026-02-07T20:42:46Z

Description

Another attempt to fix #1136.

Unlike #1159, instead of replacing http-proxy w/ http-proxy-3, the PR chooses httpxy, because:

httpxy is way more popular and more battle-tested:
- http-proxy-3 only has about 45K weekly downloads right now
- while httpxy has about 1.1M weekly downloads right now
httpxy has a smaller installation size, hence a smaller footprint:
- http-proxy-3 has 2 dependencies, its installation size is about 185 KiB (https://pkg-size.dev/http-proxy-3)
- httpxy has 0 dependency (!) and its installation size is only 57 KiB (https://pkg-size.dev/httpxy)
Though http-proxy-3 claims it is used by the Vite, httpxy is actually widely used by the Nuxt.js community, and is actually getting contributions from the Vite.js Team (refactor!: code improvements unjs/httpxy#78)!

Motivation and Context

See #1136

How has this been tested?

Unlike #1159, I actually get all the tests to pass and TypeScript happy! You can check the action log here: SukkaW#1

Types of changes

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

My change requires a change to the documentation.
I have updated the documentation accordingly.

SukkaW · 2026-02-07T20:46:12Z

cc @chimurai

Please check my PR as another attempt to fix #1136. Unlike #1159, I get all the tests to pass both on my machine locally and on CI (check SukkaW#1):

Also, I get rid of all TypeScript errors with tsc --build runs perfectly:

chimurai · 2026-02-07T22:10:50Z

Hi @SukkaW

Thanks for the PR! Didn't know about httpxy

Did a quick check and looks really nice so far. Most of the types are working.

Found a small issue in the typing where req somehow is now type any.

Added an extra check to prevent req: any (#1161)

🔧 Can you rebase with master?
You'll see the same error in:

http-proxy-middleware/test/types.spec.ts

Lines 393 to 401 in 6436ffc

    
           // responseInterceptor 
        
           proxyServer.on( 
        
             'proxyRes', 
        
             responseInterceptor(async (buffer, proxyRes, req, res) => { 
        
               req.params; 
        
               res.status(200).send('OK'); 
        
               return buffer; 
        
             }), 
        
           );

chimurai · 2026-02-07T22:15:34Z

tsconfig.json

    "strict": true,
-    "noImplicitAny": false
+    "noImplicitAny": false,
+    "skipLibCheck": true


Why was skipLibCheck: true needed?

httpxy's types rely on a default export on node:http (in its .d.ts it uses import http from 'node:http').

But this only works with moduleResolution: node16/nodenext/bundler + module: node16/nodenext/preserve setup, not with moduleResolution: node + module: commonjs setup.

So rather than changing the moduleResolution and module (which will most likely result in a huge breaking change), I just enabled skipLibCheck to avoid that.

SukkaW · 2026-02-08T07:55:30Z

Did a quick check and looks really nice so far. Most of the types are working.

Found a small issue in the typing where req somehow is now type any.

The httpxy usage of EventEmitter is not typed. I have submitted a PR to the upstream to fix it: unjs/httpxy#96

After httpxy merges that PR and releases a new version, the any we are seeing here should be gone.

SukkaW · 2026-02-11T17:59:45Z

@chimurai

The types are fixed, and all tests passed on my machine locally:

SukkaW · 2026-02-11T18:00:55Z

src/handlers/response-interceptor.ts

 type Interceptor<TReq = http.IncomingMessage, TRes = http.ServerResponse> = (
  buffer: Buffer,
-  proxyRes: TReq,
+  proxyRes: http.IncomingMessage,


proxyRes comes from the http client instead of the call site (express.js), thus this should not be TReq.

SukkaW · 2026-02-11T18:03:13Z

src/plugins/default/error-response-plugin.ts

+    if (!req || !res) {
      throw err; // "Error: Must provide a proper URL as target"
    }


Technically, req and res should either be both specified or both nullish.

However, currently, httpxy can't implement this kind of overload due to how NodeJS.EventEmitter types its event arguments via a generic (which ProxyServer is extending from), so the && is replaced with || to make the TypeScript happy down the road.

SukkaW · 2026-02-11T18:07:22Z

@chimurai Also, I am currently actively working on httpxy's HTTP/2 listener support (unjs/httpxy#38).

Update: almost done unjs/httpxy#102

SukkaW · 2026-03-05T18:22:18Z

@chimurai Hello, what else is required for the PR to merge? All TypeScript error has been fixed and the lint is now happy.

SukkaW · 2026-04-02T13:47:12Z

@chimurai Just a friendly ping, would you like to review this? All TypeScript errors have been fixed, the lint is happy, and all the tests have passed.

coveralls · 2026-04-02T17:29:05Z

coverage: 96.544% (-0.6%) from 97.15%
when pulling dacea34 on SukkaW:replace-http-proxy
into 48ed092 on chimurai:master.

chimurai · 2026-04-02T17:36:33Z

Hi @SukkaW. Thanks for the reminder. PR looks good.

CI is failing because patches need to be removed which are not needed anymore:

patches/http-proxy+1.18.1.patch

You can verify if the other patches are still needed with:

yarn patch-package

Once this is fixed, this PR can be merged 👍

Copilot

Pull request overview

This PR attempts to resolve #1136 by replacing the unmaintained http-proxy dependency with httpxy, updating the middleware implementation and exported types to match httpxy’s API/behavior.

Changes:

Swap http-proxy / @types/http-proxy for httpxy and update lockfile/spellcheck dictionary.
Refactor core proxying logic to use httpxy’s promise-based web/ws APIs and adjust error handling + shutdown behavior.
Update public TypeScript types and response interception types to align with the new proxy library.

Reviewed changes

Copilot reviewed 7 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
`package.json`	Replaces proxy dependency with `httpxy` (but note `patch-package` implications).
`yarn.lock`	Removes `http-proxy` transitive deps and adds `httpxy`.
`tsconfig.json`	Enables `skipLibCheck`.
`src/http-proxy-middleware.ts`	Migrates to `httpxy` (`createProxyServer`, async `web/ws`), adjusts error emitting and close handling.
`src/types.ts`	Switches exported proxy types from `http-proxy` to `httpxy` and redefines event callback shapes.
`src/plugins/default/proxy-events.ts`	Adjusts `on` option iteration to improve typing/narrowing.
`src/plugins/default/error-response-plugin.ts`	Changes error guard condition for rethrow behavior.
`src/handlers/response-interceptor.ts`	Corrects `proxyRes` typing to `http.IncomingMessage` and updates decompression call site.
`cspell.json`	Adds `httpxy` to allowed words list.

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src/types.ts

package.json

src/plugins/default/error-response-plugin.ts

bjohansebas · 2026-04-02T19:22:45Z

package.json

-    "@types/http-proxy": "^1.17.15",
    "debug": "^4.3.6",
-    "http-proxy": "^1.18.1",
+    "httpxy": "^0.2.2",


You should update to see how it behaves in this version, since things have changed.

Suggested change

"httpxy": "^0.2.2",

"httpxy": "^0.5.0",

There were a few breaking changes: httpxy@0.3.0 dropped Node.js legacy Url support, and httpxy@0.4.0 became ESM-only. Both will break http-proxy-middleware's support range (which is Node.js 14.18.0+)

Proposing to ship the current version + some bugfixes queued in the PRs for v4

In v5 we can make http-proxy-middleware future ready with ESM + CJS, so we can use httpxy@0.3.0+

I'll make this more visible in the roadmap 👍

SukkaW · 2026-04-03T06:11:28Z

cc @chimurai

I have rebased the PR to the latest master, and I have dropped patches/http-proxy+1.18.1.patch in dacea34 (this PR).

erictheswift · 2026-04-03T06:20:46Z

Omg folks, I’m so excited and it took less time than to implement esmodules after es2015 release😜

erictheswift · 2026-04-03T06:21:20Z

Kudos!

pkg-pr-new · 2026-04-03T08:14:06Z

npm i https://pkg.pr.new/http-proxy-middleware@1160

commit: 058d409

SukkaW mentioned this pull request Feb 7, 2026

feat(http-proxy-3): migrate from http-proxy to http-proxy alternative #1136

Open

chimurai reviewed Feb 7, 2026

View reviewed changes

SukkaW mentioned this pull request Feb 8, 2026

ProxyServer's event is not typed unjs/httpxy#95

Closed

SukkaW force-pushed the replace-http-proxy branch from b1801dd to c10521e Compare February 9, 2026 09:09

SukkaW commented Feb 11, 2026

View reviewed changes

jonatanschroeder mentioned this pull request Mar 19, 2026

Deprecation warning for http-proxy PrairieLearn/PrairieLearn#14472

Open

bjohansebas mentioned this pull request Mar 31, 2026

feat: update http-proxy dependency to http-proxy-3 #1159

Closed

5 tasks

SukkaW requested a review from chimurai April 2, 2026 13:46

chimurai force-pushed the replace-http-proxy branch from 13848fb to 548b23c Compare April 2, 2026 17:26

chimurai requested a review from Copilot April 2, 2026 19:12

Copilot started reviewing on behalf of chimurai April 2, 2026 19:13 View session

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SukkaW added 7 commits April 3, 2026 14:10

refactor(chimurai#1136): replace http-proxy w/ httpxy

d8d9ded

chore: make prettier happy

bbead0e

chore: make cspell happy

03b2ccd

refactor: make tests passed

7526c3a

chore: upgrade to latest httpxy and fix more types

118ff6a

refactor: make types happy

29215ef

chore: make lint happy

5a5e750

chore: drop outdated patch-package

dacea34

SukkaW force-pushed the replace-http-proxy branch from 548b23c to dacea34 Compare April 3, 2026 06:10

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