Google Chrome Violation: Added non-passive event

[aletheia7]

Google Chrome Console Error

[Violation] Added non-passive event listener to a scroll-blocking 'touchstart' event. Consider marking event handler as 'passive' to make the page more responsive. See https://www.chromestatus.com/feature/5745543795965952

macOS: Big Sur
Google Chrome: 89.0.4389.82
iro.js: v5.3.2

iro.js line 14
iro.js chrome formatted: line 241

Code

... u ? (t || n.addEventListener(l, T, e), ...
l = onmousedown
e = false
e should probably be { passive: true }

also
l = ontouchstart
e = false

https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener

[jaames]

I intentionally mark them as non-passive: https://github.com/jaames/iro.js/blob/master/src/ComponentWrapper.tsx#L83 , since they call preventDefault() to stop the page from scrolling while users drag the color picker handles

The error isn't fatal, it's just a minor warning since most people don't have any reason to use touch events in this way

[aletheia7]

When I sent a breakpoint, e is a boolean. e is not an object with passive set to false.

Would the Violation disappear if e was {passive: false} ?

[jaames]

Ah, looks like that code is coming from Preact, so not sure if there's anything I can do about that.

Relevant Preact issue:
preactjs/preact#428