User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

HTML:

<div id="mydiv">click me</div>
<div id="textout"></div>

JS:

var div = document.querySelector('#mydiv');
var f = function(e) {
    e.preventDefault();
    document.querySelector('#textout').innerText += e.type + "\n";
};
div.addEventListener('touchstart', f);
div.addEventListener('click', f);

On desktop (I used Linux), open the dev tools and enable Responsive Design Mode (Control+Shift+M)

Click on the first div.

Actual results:

Even though I do preventDefault, I still get both touchstart and click events on the desktop.

Additionally, if I also happen to listen for pointerdown I'm getting it twice. On mobile I only get pointerdown -> touchstart -> click if I don't preventDefault, but on desktop with dev simulated touches enabled I get pointerdown -> touchstart -> pointerdown -> click.

Expected results:

I should only get touchstart, not followed by click, when I preventDefault with simulated touches in Responsive Design Mode.

Hi Uplink,

Thanks for reporting this bug.

I was able to reproduce it on Windows 10 and Ubuntu 18.04 on the following Firefox builds:

• Nightly: 74.0a1 (2020-01-17) (64-bit)
• Beta: 73.0b6 (64-bit)
• Release: 71.0 (64-bit) and 72.0.1 (64-bit)
• ESR 68.4.2

I'm adding this issue to the Dev Tools: RDM area and hopefully, someone from their team will look over it.

Regards,
Virginia

Thank you for filing this issue! Being able to correctly simulate touch events in RDM is an upcoming priority for the tool, so we appreciate all the feedback we can get. The observations made in the bug are likely related/similar to Bug 1501939 and Bug 1538709.

Hi, Uplink! So the issue where "click" is still fired even when the handler calls preventDefault has been resolved via Bug 1623941, which is now available in Firefox Nightly (78.0a1). The second part where pointerdown is fired twice still remains an issue, which is planned to be fixed in Bug 1625827.