Fix for calling functions on proxy (navigator.webdriver evasion)

[Niek]

This fixes function calls on the navigator object, for example navigator.javaEnabled() which is called by Google Analytics.

Related Chromium bug: https://bugs.chromium.org/p/v8/issues/detail?id=5773

[berstend]

Interesting. I wonder why that's necessary though - function calls are covered by the apply proxy trap? It shouldn't be necessary to bind the target context during Object.get() (which the get trap is taking care of).

I did a quick search if Reflect.get would take care of setting the this context to the target but it doesn't seem to be doing that. I'm a bit confused as of why this is necessary but if it fixes the issues you've mentioned we shall merge it in. :)

[berstend]

Ah, well - it's a bug in Chromium so it doesn't need to make sense. 😄

[berstend]

I've added a regression test so this won't happen again in the future:

test('stealth: regression: wont kill other navigator methods', async t => {
  const puppeteer = addExtra(vanillaPuppeteer).use(Plugin())
  const browser = await puppeteer.launch({ headless: true })
  const page = await browser.newPage()

  try {
    const data = await page.evaluate(() => navigator.javaEnabled())
    t.is(data, false)
  } catch (err) {
    t.is(err, undefined)
  }
})

d495042

[Niek]

I agree it's weird, but apparently the apply trap is not called in case of native functions. Maybe it's fixed in a future Chromium release, so the regression test is a good idea.

[berstend]

Good find regardless. :) I skimmed the rest of the evasions but this seems to be the only occurrence where this fix is required.

[berstend]

Actually that's not true, found some other spots that had this issue and added the fix. 😅

[Niek]

Oops... Didn't even think of checking other evasions, good catch!

[berstend]

Released as puppeteer-extra-plugin-stealth@2.4.9 - thanks again @Niek! 💪