1581270 - browser.downloads.onCreated.addListener causing error

Status: RESOLVED DUPLICATE of bug 1576508

(WebExtensions :: Developer Tools, defect)

Description

[Joseph Wensley]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:70.0) Gecko/20100101 Firefox/70.0

Steps to reproduce:

Create an extension with a background script that registers a download created listener, and then download a file.

Example code:
browser.downloads.onCreated.addListener((downloadItem) => {
console.log('browser.downloads.onCreated', downloadItem);
});

Actual results:

The log message does not appear the web extension debugging console, but an error and warning appear in the browser console.

[Warning] Sending message that cannot be cloned. Are you trying to send an XPCOM object? MessageChannel.jsm:369:26
[Error] DataCloneError: The object could not be cloned. ExtensionParent.jsm:1213

Expected results:

The downloadItem for the downloaded file should be logged to the console.

Comment 1

[Liviu Seplecan]

Attachment: bug 1581270.png

Comment 2

[Liviu Seplecan]

Hi @Joseph Wensley, checked the issue on several machines & FF versions:
[Platform affected]: Windows 10, Mac OS X, Ubuntu 18.04
[FF versions]: nightly 71.0a1, beta 70.0b7, release 69.0.1

=> on all machines and FF versions I get the same messages as are presented in the description. I will add a screenshot to see how it looks in my end. Further, I will add a component, if isn't the right one please fell free to change it.
Regards,
Liviu

Comment 3

[Daniel B.]

I can confirm this issue on Firefox 70.0b6 (Build ID 20190912160217), but not on Firefox 69.0 (20190827005903).

Here’s the complete code I used to test this: https://github.com/fuzzykiller/download-cleaner-lite/tree/test-firefox70-regression

onDownloadChanged still works as expected.

Comment 4

[Luca Greco [:rpl] [:luca] [:lgreco]]

Closed as a duplicate, this should be the same regression we already fixed in Bug 1576508.