Swipeable sidebars on MacOS

There is no “normal Mac behavior” for this. It is not a traditional Mac gesture.

On iOS, the interaction is different, in the sense that you swipe across the screen. With the Mac, the pointer stays at the same location, but you use a kind-of scroll wheel gesture to get the swipe. So the two are not exactly comparable, but iOS also does use the location of the swipe in a similar way, because you can swipe across the edge you want to close. That is like putting the cursor near that edge on the Mac.