Encountering SyntaxError related to nullish coalescing assignment in Puppeteer

Other Questions Puppeteer
1

I’m facing an issue with my Puppeteer code when deploying it in a production setting. The code executes flawlessly on my local machine, but I run into errors when attempting to execute it on Docker or platforms like Render.

const puppeteer = require('puppeteer');
const fs = require('fs');
const path = require('path');

const createPDF = async ({ userId, fileName }) => {
  // Launch headless browser
  const browser = await puppeteer.launch();
  
  // Open a new tab
  const page = await browser.newPage();
  
  // Navigate to the PDF generation URL
  await page.goto(`http://localhost:3000/document/pdf/${userId}`);
  
  // Set viewport parameters
  await page.setViewport({ width: 800, height: 600 });
  
  // Create the PDF
  await page.pdf({
    path: `pdfOutput/${userId}.pdf`,
    format: 'A4',
    printBackground: true,
    margin: { top: '15px', right: '15px', bottom: '15px', left: '15px' }
  });
  
  // Close the browser
  await browser.close();
};

The exact error message I’m receiving is:

SyntaxError: Unexpected token '??='
    at internal/modules/esm/translators.js:149:18

This appears to be an issue originating from Puppeteer’s internal configuration files. While my local setup runs smoothly, I consistently encounter failures during production deployment. What might be the reason for this discrepancy between local execution and the production environment?

2

Had this exact problem moving from dev to production. Docker base images usually default to older Node versions. Your package.json version doesn’t matter - the container runs whatever runtime it has. I fixed it by explicitly setting the Node version in my Dockerfile: FROM node:18-alpine instead of FROM node:alpine. Also check if your hosting platform has Node version settings - most services default to older stable versions unless you specify otherwise. The nullish coalescing assignment operator is pretty new and Puppeteer’s internals use it, so anything below Node 15 will throw this syntax error.

3

This happens when your Node.js versions don’t match between local and production. The ??= operator needs Node 15.0.0 or higher - if production runs an older version, you’ll get this syntax error even though it works fine locally. I hit the same thing deploying to shared hosting that was still on Node 14. Puppeteer’s dependencies use modern JS features that older Node versions can’t handle. Check your production Node version with console.log(process.version) or node --version in your deployment environment. It’s probably below 15.0.0. Update production to at least Node 15.0.0, but I’d go with a recent LTS like 18.x or 20.x.

4

Yeah, this is definitely a node version mismatch. Puppeteer uses modern syntax and production environments usually default to older node versions. Check your render dashboard settings - you can specify the node version in environment variables or config files. I switched from automatic to node 18 and it fixed the same error immediately.