[Bug]: page.waitForResponse results in "Buffer is not defined" error when reading response

[apeacock1991]

Bug description

Steps to reproduce the problem:

1. …

const [res] = await Promise.all([
            page.waitForResponse(res => res.url().includes('something') && res.request().method().toUpperCase() != "OPTIONS"),
            page.goto('https://example.com', {waitUntil: "domcontentloaded"}),
        ]);

console.log(await res?.buffer())

You'll need to adjust the URL/matcher, but when you call res.buffer() (or .text() or .json()) it raises a Buffer is not defined error.

I tested the same code on the core Puppeteer library and it worked fine.

Puppeteer version

0.0.4

Node.js version

16

npm version

9.5.1

What operating system are you seeing the problem on?

macOS

Relevant log output

No response

[lucaswalter]

I wanted to share I am getting a very similar error on my worker which was previously working from a few days ago where I take a screenshot of my own site.

            browser = await puppeteer.launch(env.OG_IMAGE_BROWSER);
            page = await browser.newPage();
            page.setViewport({ width: 1920, height: 1080, deviceScaleFactor: 2 });

            // Open Game Page
            await page.goto(`https://steambase.io/games/${appId}`);
            await page.waitForSelector('#app-stats-line-chart.loaded');

            // Capture Screenshot
            const img = await page.screenshot({
                type: 'png'
            });

This is the error I get when viewing the CF worker logs:

    {
      "message": [
        "ReferenceError: Buffer is not defined"
      ],
      "level": "error",
      "timestamp": 1689949193979
    }

[sizovs]

Same here.

[bhanderivaibhav]

mine is failing at initializing browser.

const browser = await puppeteer.launch(env.MYBROWSER);

[AlwaysAwake]

Same here.

[denu5]

update your dependencies incl. node to node 18 lts and try to add: compatibility_flags = [ "nodejs_compat" ]

similar:

#15 (comment)

[sizovs]

@denu5 Thank you. I tried all Node versions from 16 to 19 (with nodejs_compact flag enabled), but it didn't help.

[cahmetcan]

I have the same problem even though i enabled nodejs_compact flag

[roelmagdaleno]

I had the same problem when initializing the browser and I found a comment in Cloudflare's Discord with this solution:

import { Buffer } from 'node:buffer';
import puppeteer from "@cloudflare/puppeteer";

globalThis.Buffer = Buffer;

Basically, import the Buffer before puppeteer and register globally, so the library can be access from anywhere.

Hope that helps.

[meddulla]

@bhanderivaibhav That error can be due to a mismatch between the variable name defined in wrangler.toml and the name used in the worker code itself. So, in wrangler.toml:

browser = { binding = "MY_BROWSER", type = "browser" }

and in the worker

export default {
	async fetch(request, env, ctx) {
		const browser = await puppeteer.launch(env.MY_BROWSER); // MUST equal the binding name defined in wrangler 
                 //....
        }
}

Also check #15 (comment)

[meddulla]

@apeacock1991 Can you try with the latest versions of wrangler (3.5.1) and cloudflare/puppeteer (0.0.5)? Can reproduce that error with version 0.0.4 but not with 0.0.5 version. Other things to check out for in wrangler.toml:

compatibility_date = "2023-05-12"

compatibility_flags = ["nodejs_compat"]

[sizovs]

The solution by @roelmagdaleno fixed the problem for me. Thank you!