Buffer is not defined

What version of Remix are you using?

1.3.5

Steps to Reproduce

• setup a remix cloudflare-worker project with mantine or any other library that uses Buffer. I followed the remix directions on the mantine site.
• remix build: works fine
• wrangler publish : fails

I can make a demo project that fails, if you want to try to deploy it to your own cloudflare.

Expected Behavior

Should output code that can be deployed on cloudflare.

Actual Behavior

It was reported at #2625 but said to be fixed in 1.3.5, so it may be some combination of remix/mantine/etc. I can build in remix fine, but on deploy (via wrangler), I get this:

✘ [ERROR] Received a bad response from the API

  Uncaught ReferenceError: Buffer is not defined
    at line 4699
    at line 33
    at line 5472
    at line 33
    at line 6626
    at line 33
    at line 6704
    at line 33
    at line 94195
   [code: 10021]


  If you think this is a bug, please open an issue at:
  https://github.com/cloudflare/wrangler2/issues/new

Normally, in other builders, a polyfill can be used, either in esbuild config, which we can’t edit in remix, or by importing buffer. If I install buffer module & and this in server entry-point:

/* global addEventListener  */

import buffer from 'buffer'

import { createEventHandler } from '@remix-run/cloudflare-workers'
import * as build from '@remix-run/dev/server-build'

globalThis.Buffer = buffer

addEventListener(
  'fetch',
  createEventHandler({ build, mode: process.env.NODE_ENV })
)

I get this error:

Building Remix app in production mode...
It appears you're using a module that is built in to node, but you installed it as a dependency which could cause problems. Please remove buffer before continuing.
Error
    at Object.onBuildFailure (/Users/konsumer/Documents/work/PROJECT/node_modules/@remix-run/dev/cli/commands.js:150:13)
    at buildEverything (/Users/konsumer/Documents/work/PROJECT/node_modules/@remix-run/dev/compiler.js:280:13)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Object.build (/Users/konsumer/Documents/work/PROJECT/node_modules/@remix-run/dev/compiler.js:105:3)
    at async Object.build (/Users/konsumer/Documents/work/PROJECT/node_modules/@remix-run/dev/cli/commands.js:145:3)
    at async Object.run (/Users/konsumer/Documents/work/PROJECT/node_modules/@remix-run/dev/cli/run.js:467:7)

[3x071c]

Cloudflare runs on V8 natively, without the additional Node.js abstraction. This means certain APIs, such as Buffer, aren’t available for your dependencies to use in Cloudflare Workers/Pages. Try this, it allows you to override Remix’s esbuild configuration to inject/alias polyfills. Here’s an example on how to replace the Buffer API. If you want a full production usage example, check out this repository. I agree that Remix should be polyfilling Buffer by default on CF though, it’s definitely a hurdle for adoption. (I think there already is an issue about that)

[kevinwolfcr]

@konsumer I just followed this guide and it worked.

I am using all the latest versions from remix and mantine packages as of today.