UnhandledPromiseRejectionWarning on Navigation Timeout Exceeded

Steps to reproduce

Environment:

• Puppeteer version: 1.3.0
• Platform / OS version: macOS 10.13.1
• Node.js version: 8.9.4

Steps

Below is the code producing this problem:

try {
  ...
  await page.waitForNavigation({waitUntil: 'networkidle2'})
  ...
} catch (err) {
  // Throw an error.
  throwError(err, page, browser, res)
}

throwError = (async (err, page, browser, res) => {
    // Log the error.
    console.log(err)

    // Close the browser.
    await page.close()
    await browser.close()

    // Return an error response message.
    res.json({code: 'ERROR', message: 'An unexpected error has occurred.'})
})

When a request times out, I get the following error:

Error: Navigation Timeout Exceeded: 30000ms exceeded
    at Promise.then (node_modules/puppeteer/lib/NavigatorWatcher.js:73:21)
    at <anonymous>
(node:72563) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Protocol error (Runtime.callFunctionOn): Target closed.
(node:72563) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

What is the expected result?

The page and browser should get closed without throwing an exception/error.

What happens instead?

Error: Protocol error (Runtime.callFunctionOn): Target closed. is displayed instead of the page and browser getting closed gracefully. Timeout Exceeded error is understandable and is correct.

I want to understand why Error: Protocol error (Runtime.callFunctionOn): Target closed. is being thrown and how we can avoid it?

[aslushnikov]

@Aetheryx Thanks, I see what’s going on here. That’s somewhat related to #1454; as a workaround, I’d recommend navigating until domcontentloaded event:

await page.goto('https://discordbots.org', {waitUntil: 'domcontentloaded'});

[motsmanish]

‘load’ worked for me:

await page.goto('http://example.com', {waitUntil: 'load'});