fix: Annotate potentially blocking event listeners with passivity #9555
+42
−8
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The basics
The details
Resolves
Fixes #9542
Proposed Changes
This PR updates
(conditional)Bindto take an additional optional parameter corresponding to theaddEventListeneroptionsargument. This allows us to specify whethertouchstartandwheelevents are or are not passive. Passive events are those which will never callpreventDefault(); in that case, performance can be improved because the browser can run the event handler asynchronously, whereas if there is a possibility ofpreventDefault()being called, the browser needs to run the whole event handler before scrolling or responding to the touch in case the event handler prevents it, which causes jank commensurate with the complexity of the event handler.Chrome has started notifying about this in the console, so this also cleans that up. There is still some logging about
touchstartin the advanced playground, but it seems that that's coming from one of its dependencies.