Button: uniform text wrapping across variants

[ciampo]

It would be interesting to understand why the default button doesn't use white-space: nowrap while the primary, secondary, and tertiary variants do. I do understand the link variant should allow text to wrap, but why the default does? GIF to illustrate:
Cc @WordPress/gutenberg-components

Originally posted by @afercia in #65491 (comment)

Follow-ups

• Undo the temporary fix in Editor: Prevent wrapping text when showing icon labels in header #66038
• Look for more places where this change could cause regressions

[ciampo]

Moving the above conversation to a separate issue. We'd have to probably look into when the white-space: nowrap style was added to understand more about the need for such feature.

In theory we should be able to support such wrapping in the default button too, although as always when Button is involved, the implications of a small change can still be numerous.

@WordPress/gutenberg-design , can you think of a reason why we should not do this, at least in principle?

[jasmussen]

I sometimes use GitHub Lens to find context for a particular line of code. In this case, it takes me to #19058, which just suggests to me that it's a missing beat.

Edit: I see it was only added to .is-button though, and not added to .is-default, which may just be something that was missed.

[afercia]

I think white-space: nowrap was originally added in #6562 to avoid the component to rely on styles provided by Core. In fact, the Core buttons do use white-space: nowrap.

[tyxla]

In theory we should be able to support such wrapping in the default button too, although as always when Button is involved, the implications of a small change can still be numerous.

This. This could actually be considered a potentially breaking change.

[ciampo]

This could actually be considered a potentially breaking change.

Potentially, although we could apply the change at the start of a release process, giving folks ample time to test their UIs, and add a dev note about it too. Also, in a way this could be seen as a bug fix — we could argue that the Button component was always meant to have white-space: nowrap and that it was just missed on the default variant.

[tyxla]

This could actually be considered a potentially breaking change.

Potentially, although we could apply the change at the start of a release process, giving folks ample time to test their UIs, and add a dev note about it too. Also, in a way this could be seen as a bug fix — we could argue that the Button component was always meant to have white-space: nowrap and that it was just missed on the default variant.

I wouldn't be opposed to that 👍

[ciampo]

Tentative PR: #66068

Let's test extensively to understand the potential for any visible regressions