🐛 BUG: `ReferenceError: __name is not defined` in `await page.evaluate(async () => {...}`

[L480]

Which Cloudflare product(s) does this pertain to?

Workers Runtime, Wrangler

What version(s) of the tool(s) are you using?

3.83.0

What version of Node are you using?

20.18.0

What operating system and version are you using?

Ubuntu 22.04.5 LTS

Describe the Bug

Observed behavior

ReferenceError: __name is not defined worker exception after wrangler deploy.
I'm having this error inside of await page.evaluate(async () => {...} code for puppeteer. It adds __name to my arrow function for some reason. I think this is likely due to minifyIdentifiers in esbuild. This behavior appeared in wrangler 3.83.0. However, it is working in wrangler 3.78.12.

Expected behavior

No minified function names in await page.evaluate(async () => {...}.

Steps to reproduce

Please provide the following:

• A minimal working subset of your worker code

import { Page } from '@cloudflare/puppeteer'

export async function scrapeDetails(page: Page) {
    await page.goto('https://example.com')
    const data = await page.evaluate(() => {
        function toNumber(str: string | undefined): number | undefined {
            const num = typeof str === 'string' ? str.replaceAll('.', '').replaceAll(',', '.').match(/[+-]?([0-9]*[.])?[0-9]+/) : false
            if (num) {
                return Number(num[0])
            } else {
                return undefined
            }
        }

        const table = document.getElementById('test')
        let metadata = {} as { test: number | undefined }
        if (table) {
            for (let item of table.getElementsByTagName('li')) {
                const data = item.innerText.split('\n')
                switch (data[0]) {
                    case 'test':
                        metadata.test = toNumber(data[1])
                        break
                }
            }
        }
        return metadata
    })
    return data
}

Get's bundled into:

async function scrapeDetails(page) {
  await page.goto("https://example.com");
  const data = await page.evaluate(() => {
    function toNumber(str) {
      const num = typeof str === "string" ? str.replaceAll(".", "").replaceAll(",", ".").match(/[+-]?([0-9]*[.])?[0-9]+/) : false;
      if (num) {
        return Number(num[0]);
      } else {
        return void 0;
      }
    }
    __name(toNumber, "toNumber"); // <== This is the issue
    const table = document.getElementById("test");
    let metadata = {};
    if (table) {
      for (let item of table.getElementsByTagName("li")) {
        const data2 = item.innerText.split("\n");
        switch (data2[0]) {
          case "test":
            metadata.test = toNumber(data2[1]);
            break;
        }
      }
    }
    return metadata;
  });
  return data;
}

• A minimal working subset of your wrangler.toml

name = "my-app"
main = "src/index.ts"
compatibility_date = "2024-09-02"
logpush = false
tail_consumers = [{service = "law-ingestion"}]
compatibility_flags = [ "nodejs_compat" ]

[triggers]
crons = ["*/15 * * * *"]

Please provide a link to a minimal reproduction

No response

Please provide any relevant error logs

No response

[pchason]

I'm experiencing the same bug, although it occurs when page.waitForSelector() is called using wrangler 3.83.

[penalosa]

This looks like it was caused by #6902, which was released in Wrangler 3.80.1. Reverting to 3.80.0 should work as a workaround for now, but this is definitely a bug we should fix. esbuild injects both the __name() fn definition and usage, and so it seems like Wrangler might be messing that up somehow?

[akngs]

A function passed to page.evaluate() as an argument runs in a separate in-browser context (Puppeteer). In this context, there is no __name() function, which results in the error __name is not defined. Since Puppeteer's page.evaluate() is essentially a hack, esbuild cannot detect this through static analysis alone. 😢

[udfordria]

I was able to solve the issue by using a string instead : puppeteer/puppeteer#1665 (comment)

[Zisan-uzum]

Im having same issue while trying to trigger recapctha callback function.

[pchason]

@ruifigueira is there a fix scheduled for cloudflare puppeteer similar to what you applied to cloudflare playwright?

I've tried these solutions to resolve but none work:

• Stringify function
• page.evaluateOnNewDocument(() => (window.__name = (func) => func))

As far as I can tell, esbuild is applying __name to functions non-user supplied page.evaluate() functions like these that are part of the puppeteer API __name(pollRaf, "pollRaf"). When puppeteer executes __name(pollRaf, "pollRaf") in the browser page, this error occurs:

Error: Evaluation failed: ReferenceError: __name is not defined
at pollRaf (pptr://puppeteer_evaluation_script:51:35)
at waitForPredicatePageFunction (pptr://puppeteer_evaluation_script:12:20)
at pollRaf (pptr://puppeteer_evaluation_script:51:35)
at waitForPredicatePageFunction (pptr://puppeteer_evaluation_script:12:20)
at ExecutionContext._ExecutionContext_evaluate (file:///.wrangler/tmp/dev-9q0MIE/index.js:42513:11)
at async WaitTask.rerun (file:///.wrangler/tmp/dev-9q0MIE/index.js:45408:17)

[ruifigueira]

@pchason here's a working example:

import puppeteer from '@cloudflare/puppeteer';

export default {
  async fetch(request, env): Promise<Response> {
    const browser = await puppeteer.launch(env.MYBROWSER);
    const page = await browser.newPage();
    function pageEvaluate(fn: Function) {
      return page.evaluate(`(() => { const __name = (target) => target; return (${fn.toString()})(); })()`);
    }

    const meaningOfLife = await pageEvaluate(() => {
      function meaningOfLife() {
        return 42;
      }
      return meaningOfLife();
    });
    return new Response(`The meaning of life is ${meaningOfLife}`);
  },
} satisfies ExportedHandler<Env>;

[pchason]

Thanks for the quick response! Dropping your code into my app and reporting back.