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MessageChannel is not defined
See original GitHub issueBasic info:
I am attempting to use Zombie.js (which uses jsdom) to debug Message Channel generation, but it doesn’t seem to be defined. According to the MDN docs, the MessageChannel constructor has support going all the way back to IE10, so it seems strange that it’s not supported here
- Node.js version: 10.10.0
- jsdom version: 13.0.0
Minimal reproduction case
'use strict';
// Let's see if MessageChannel is supported
let html = `
<!DOCTYPE html>
<body>
<h1 id='title'>
Does MessageChannel Exist?
</h1>
<script>
var title = document.getElementById('title');
try {
window.channel = new MessageChannel();
} catch(e) {
console.log('Error caught: ' + e.message)
}
if (window.channel) {
title.innerHTML = 'MessageChannel Exists!';
} else {
title.innerHTML = 'MessageChannel Does not Exist :(';
}
</script>
</body>
</html>
`;
const { JSDOM } = require('jsdom');
const { window } = new JSDOM(html, {runScripts: 'dangerously'});
console.log(window.eval('document.getElementById("title").innerHTML'));
// Expected -> 'MessageChannel Exists!'
// Actual ---> 'MessageChannel Does not Exist :('
Running the above node file should print the string “MessageChannel Exists!” and produce no errors. However, when running using jsdom a “MesssageChannel is not defined” error is thrown, and the console logs “MessageChannel Does not Exist 😦”
How does similar code behave in browsers?
Example of working code in JSFiddle: https://jsfiddle.net/hvLpg6tm/5/
The HTML provided is exactly the same
Issue Analytics
- State:
- Created 5 years ago
- Reactions:7
- Comments:6
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Looks like one could just do this as of Node 10.5.0:
Source: https://nodejs.org/api/worker_threads.html#worker_threads_class_messagechannel
However, one needs to pass Node the
--experimental-workerflag.If someone adds this, there is one concern that I think needs to be resolved.
jsdom sandboxes timers. I.e.
setTimeoutandsetIntervaldon’t hold the Node process hostage if you callwindow.close(). They’re automatically cancelled.I believe that jsdom should do the same for
MessageChannelports, if it were to addwindow.MessageChannel. Concretely,window.close()should also close all open ports. Otherwise, the Node process won’t exit.