UnhandledPromiseRejectionWarning: Error: Protocol error (Runtime.callFunctionOn): Target closed. (Puppeteer)

Question

I am new to Puppeteer and Node and I get this error when trying to execute the following code:

'use strict';

const puppeteer = require('puppeteer');
const evalLib = require('./oaa_a11y_evaluation.js');

function evaluateRules() {
  var ruleset = OpenAjax.a11y.RulesetManager.getRuleset("ARIA_STRICT");
  var evaluator_factory = OpenAjax.a11y.EvaluatorFactory.newInstance();
  evaluator_factory.setParameter('ruleset', ruleset);
  evaluator_factory.setFeature('eventProcessing', 'fae-util');
  evaluator_factory.setFeature('groups', 7);
  var evaluator = evaluator_factory.newEvaluator();
  var evaluation = evaluator.evaluate(window.document, document.title, document.location.href);
  // var out = evaluation.toJSON(true);
  return;
}

(async() => {
  const browser = await puppeteer.launch();
  var page = await browser.newPage();
  await page.goto('http://mihirkumar.com/', {waitUntil: 'load'});
  page.evaluate(evaluateRules);
  await browser.close();
})();

Here's the error message in full detail:

(node:27876) UnhandledPromiseRejectionWarning: Error: Protocol error (Runtime.callFunctionOn): Target closed.
at Promise (C:\Users\Mihir\fae\node_modules\puppeteer\lib\Connection.js:200:56)
at new Promise (<anonymous>)
at CDPSession.send (C:\Users\Mihir\fae\node_modules\puppeteer\lib\Connection.js:199:12)
at ExecutionContext.evaluateHandle (C:\Users\Mihir\fae\node_modules\puppeteer\lib\ExecutionContext.js:79:75)
at ExecutionContext.evaluate (C:\Users\Mihir\fae\node_modules\puppeteer\lib\ExecutionContext.js:46:31)
at Frame.evaluate (C:\Users\Mihir\fae\node_modules\puppeteer\lib\FrameManager.js:326:20)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
(node:27876) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:27876) [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.

Other examples from https://github.com/GoogleChromeLabs/puppeteer-examples run perfectly fine so I don't believe I need to use the fixes mentioned here. Thanks for the help.

Is your problem that you don't know how to handle that unhandled rejection, or that you don't know why you get that protocol error? — Bergi, Jun 01 '18 at 14:13
I don't know how to handle the rejection and I don't know why it's occurring/what I'm doing wrong to cause it. Apart from the obvious message 'Target closed' I don't know much more. — Mihir Kumar, Jun 01 '18 at 14:16
Handle rejections with `try`/`catch` around the `await`. Though in this case there's no much you can do other than print the error message and fail your test. — Bergi, Jun 01 '18 at 14:17
Putting a try catch around the awaits isn't making the problem go away. — Mihir Kumar, Jun 01 '18 at 14:22
Yes, it's just making the "unhandled rejection warning" go away. I have no idea what the problem that causes the protocol error could be - but if that's what you want to know, you should [edit] your question and provide a more appropriate title. — Bergi, Jun 01 '18 at 14:25
If you wrap the `await` expressions in a `try/catch`-block, and add an `await page.close()` *before* the `await browser.close()`, do you get a different result? — Sven, Jun 01 '18 at 14:30
It's also worth mentioning that `page.evaluate()` returns a promise, so you should `await` it. At the moment, you are not waiting for it to finish, and are immediately executing `browser.close()` before `page.evaluate()` has finished. — Sven, Jun 01 '18 at 14:34
See also [Puppeteer - Protocol error (Page.navigate): Target closed](https://stackoverflow.com/questions/51629151/puppeteer-protocol-error-page-navigate-target-closed/68231165#68231165) — ggorlen, Jul 02 '21 at 21:05

score 5 · Answer 1 · edited Jul 02 '21 at 21:04

As Sven mentioned in the comments, you should use await on every page function that returns a promise (that's almost all of them) before closing the browser.

Try this:

'use strict';

const puppeteer = require('puppeteer');
const evalLib = require('./oaa_a11y_evaluation.js');

async function evaluateRules() {
  var ruleset = OpenAjax.a11y.RulesetManager.getRuleset("ARIA_STRICT");
  var evaluator_factory = OpenAjax.a11y.EvaluatorFactory.newInstance();
  evaluator_factory.setParameter('ruleset', ruleset);
  evaluator_factory.setFeature('eventProcessing', 'fae-util');
  evaluator_factory.setFeature('groups', 7);
  var evaluator = evaluator_factory.newEvaluator();
  var evaluation = evaluator.evaluate(window.document, document.title, document.location.href);
  // var out = evaluation.toJSON(true);
  return;
}

(async() => {
  const browser = await puppeteer.launch();
  var page = await browser.newPage();
  await page.goto('http://mihirkumar.com/', {waitUntil: 'load'});
  await page.evaluate(evaluateRules); // <-- await here
  await browser.close();
})();

score 1 · Accepted Answer · answered Jun 28 '18 at 00:20

Thanks for the responses. Making the function async is definitely a change for the better. My problem was that I wasn't injecting the OpenAjax javascript libraries into the loaded page. Once I did that with puppeteer's page.addScriptTag function things worked just fine.

score 0 · Answer 3 · answered Dec 07 '21 at 21:26

If U are using jest just add "exitOnPageError: false" on

module.exports = {
  server: {
    command: "PORT=3005 BROWSER=none react-scripts start",
    port: 3005,
    launchTimeout: 30000,
  },
  launch: {
    headless: process.env.HEADLESS !== "false",
    devtools: true,
  },
  exitOnPageError: false
};

UnhandledPromiseRejectionWarning: Error: Protocol error (Runtime.callFunctionOn): Target closed. (Puppeteer)

3 Answers3

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