Popover placement "right-start" doesn't display an arrow

[Jeff-Mott-OR]

Describe the bug

An overlay with a placement of "right-start" will not display an arrow.

To Reproduce

1. Go to https://react-bootstrap.github.io/components/overlays/#popovers
2. Edit code sample. Change "right" to "right-start"
3. See error

Screenshots

Environment (please complete the following information)

• Operating System: Win10
• Browser, Version: Chrome 75
• React-Bootstrap Version: 1.0.0-beta.9

[taion]

Bootstrap doesn't support right-start positioned popovers: https://getbootstrap.com/docs/4.3/components/popovers/#four-directions

You may be able to pass in the placement directly via popperConfig and override whatever is determined from placement as passed down to <Overlay>.

[Jeff-Mott-OR]

React-bootstrap docs say right-start is a supported placement. Am I misinterpreting? https://react-bootstrap.github.io/components/overlays/#overlay-props

[taion]

Would you care to send in a PR to update those docs, then? As you've noted, it won't work with anything other than the cardinal directions.

[Jeff-Mott-OR]

In terms of vertical alignment, right-start does work, and I presume the others do as well. The only issue is we don't get the arrow when using right-start. Is deleting it from the docs really the right thing to do?

[taion]

Well, it really varies. Maybe a better thing to do is to note that, for things like popovers, the diagonal placement options don't fully work.

But ultimately you can't render a <Popover placement="right-start">, so our docs should reflect that to some extent.

[bpas247]

I'm guessing we'd need to change the propTypes for Popover as well?

react-bootstrap/src/Popover.js

Line 36 in 49a4563

'right-start',

[taion]

Yes – it's that plus noting with <OverlayTrigger> that the placement specified must also be valid for the overlay you're mounting.

[hitbear518]

How to use popperConfig to make right-start work?
I tried popperConfig={{ placement: 'top-start' }} on Overlay and Tooltip, but doesn't work