GoogleChrome / GoogleChrome/lighthouse

Cannot trigger "Does not use passive listeners to improve scrolling performance" violation

Open
#12,226 2 comments 0 reactions 1 assignee Claimed by @paulirish View on GitHub
needs-investigation needs-priority
Dominant language
JavaScript
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Description

#### Provide the steps to reproduce
1. Run LH on https://1p98o.csb.app/

```js
// make the body scrollable
document.body.style.setProperty(
'height',
'150vh',
);

// this *should* cause a violation
window.addEventListener(
'wheel',
function onWheel(event) {
console.log('not passive');
},
{
passive: false,
},
);

// this is fine and does not cause a violation
window.addEventListener(
'wheel',
function onWheel(event) {
console.log('passive');
},
{
passive: true,
},
);
```

#### What is the current behavior?

Adding a non-passive `wheel` (or `mousewheel`), `touchstart` or `touchmove` event listener to the `window`, `document` or `body` is *not* triggering a ["Does not use passive listeners to improve scrolling performance"](https://web.dev/uses-passive-event-listeners/) violation

#### What is the expected behavior?

It would trigger a violation

#### Environment Information
* Affected Channels: DevTools (have not tested other channels)
* Lighthouse version: `7.0.0` and `7.2.0`
* Chrome version: `89.0.4389.82` and `91.0.4440.0`

Cheers

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