Experimental Firefox support appears to not work

[foolip]

The puppeteer.launch({product: 'firefox'}) pattern does not appear to launch Firefox.

Steps to reproduce

Tell us about your environment:

• Puppeteer version: 2.1.1
• Platform / OS version: Debian 5.2.17 (gLinux)
• Node.js version: v10.15.3

What steps will reproduce the problem?

Please include code that reproduces the issue.

const puppeteer =  require('puppeteer');
const products = ['chrome', 'firefox'];

async function main() {
  for (const product of products) {
    const browser = await puppeteer.launch({product});
    const page = await browser.newPage();
    const ua = await page.evaluate('navigator.userAgent');
    console.log(`${product}: ${ua}`);
    await browser.close();
  }
}

main();

What is the expected result?

Different UA strings for Chrome and Firefox.

What happens instead?

It looks like Chrome is launched in both cases, that the {product: 'firefox'} option has no effect:

chrome: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/80.0.3987.0 Safari/537.36
firefox: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/80.0.3987.0 Safari/537.36

[pavelfeldman]

👋 @foolip. I could make it start via specifying the environment variables that I saw in the announcement tweet. But it failed (F), timed out (T), skipped (*) a bunch of tests until it died (pink dot):

@mathiasbynens: is there a way to track the FF support status? Something like isplaywrightready would be handy.

[mjzffr]

Ah yeah, you have to specify the executablePath for Firefox. That won't be necessary anymore after PR #5467 is merged.