New smooth scroll option in ScrollSpy not working

[SamuelMiller]

Prerequisites

• I have searched for duplicate or closed issues
• I have validated any HTML to avoid common problems
• I have read the contributing guidelines

Describe the issue

Using the latest js and css beta 5.2 Bootstrap, I am unable to get the new smooth scroll option in Scrollspy to work on the website I am starting to develop, using <div data-bs-spy="scroll" data-bs-target=".navbar" data-bs-smooth-scroll="true"> Clicking on scroll-to links in the top menu jumps to the anchor sections rather than smoothly scroll as it did before. There is no difference. I thought there might be a conflict with CSS scroll snap. But disabling that class in the CSS does not change anything.

Reduced test cases

I've duplicated the issue on Codepen, including custom Javascript:
https://codepen.io/sam-miller-the-flexboxer/pen/BaYpvPL

What operating system(s) are you seeing the problem on?

macOS

What browser(s) are you seeing the problem on?

Chrome, Safari, Firefox, Microsoft Edge

What version of Bootstrap are you using?

beta 5.2v

[GeoSot]

Maybe smoothScroll is misleading, as its main purpose is to stop doc scrolling.
Although, here is the place you could experiment on

bootstrap/js/src/scrollspy.js

Lines 129 to 140 in 416f490

	const height = observableSection.offsetTop - this._element.offsetTop
	if (root.scrollTo) {
	root.scrollTo({ top: height })
	return
	}
	// Chrome 60 doesn't support `scrollTo`
	root.scrollTop = height
	}
	})
	}

changing to something like root.scrollTo({ top: height, behavior: 'smooth' }) and open a PR 😃

[SamuelMiller]

The documentation (https://getbootstrap.com/docs/5.2/components/scrollspy/) is not clear. It states that smooth scroll "enables smooth scrolling when a user clicks on a link that refers to ScrollSpy observables." The term "smooth scrolling" usually refers to the animated smooth scrolling effect when clicking on a link to a different part of the page. For an example, see https://codepen.io/prvnbist/pen/GQMPZq click on a top right menu item and see how the page slowly scrolls (animates scrolling) to the new section. If that's not the effect that enabling "smooth scroll" does in ScrollSpy bootstrap 5.2 then I suggest the term be changed.