Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

document.querySelectorAll returns stale results

See original GitHub issue

Basic info:

Node.js version: v8.11.4
jsdom version: v13.2.0 (bug is also present in v11.12.0)

Minimal reproduction case

const jsdom = require('jsdom');
const {JSDOM} = jsdom;

function append(html) {
  document.body.innerHTML = html;
}

function clean() {
  document.body.innerHTML = '';
}

const dom = new JSDOM(`<!DOCTYPE html>`);
const document = dom.window.document;

const fixtures = {
  a: '<a id="link-a" class="test">a link</a>',
  b: '<a id="link-b" class="test"><img src="foo.jpg" /></a>'
};

append(fixtures.a);
console.log(document.body.innerHTML);
// should log "link-a"
document.querySelectorAll('a.test').forEach(node => console.log(node.id));
clean();

append(fixtures.b);
console.log(document.body.innerHTML);
// should log "link-b"
document.querySelectorAll('a.test').forEach(node => console.log(node.id));
clean();

append(fixtures.a);
console.log(document.body.innerHTML);
// should log "link-a", but logs "link-b"
document.querySelectorAll('a.test').forEach(node => console.log(node.id));
clean();

How does similar code behave in browsers?

https://jsbin.com/fobuxoceva/edit?js,console

Pretty much what the title says. document.querySelectorAll returns Nodes which have been removed already. I suspect this is an issue of memoization of queries: If the last querySelectorAll('a.test') is changed to querySelectorAll('.test') (parameters are different from previous calls), it works as expected. AFAIK memoization for querySelectorAll has been removed here: https://github.com/jsdom/jsdom/commit/bfb08434f540491591aace17b302816f146dd4ef

Context

We discovered this while move old jasmine tests over to jest which uses jsdom. I guess adding and removing DOM nodes between unit tests isn’t anything exotic.

Issue Analytics

State:
Created 5 years ago
Comments:7 (2 by maintainers)

Top GitHub Comments

1reaction

domeniccommented, Feb 23, 2019

Some discussion going on in https://github.com/dperini/nwsapi/pull/23; hopefully that gets fixed in nwsapi as this kind of breaking change in a minor version is not really OK 😦.

0reactions

ghostcommented, Mar 1, 2019

@sscaetite This looks correct and unrelated to this issue. You shouldn’t trust console.log to display the contents of your divs. Try to log the actual HTML using node.outerHTML.