For those who fuss over spacing

I had hoped that the non-breaking thin space would change everything.

Here’s an italicized word in parentheses: (test).

Ugly, no?

Here’s the same text with the addition of a thin space —   — before the closing parenthesis: (test ).

Better, yes?

But the thin space functions like an ordinary space. With the insertion of a thin space, characters that should stay together can end up split across two lines, like so: (test 
).

That’s a faked example. But it does happen. You can guess how I know that.

Enter the non-breaking thin space —   or  . It’s slightly wider than a thin space, and it’s supposed to be, as its name suggests, unbreakable. But it breaks. You can guess how I know that too. Here’s what I saw as a Preview while working on an earlier post:

[That’s what I get for making a silly plural.]

I think that   and   are interchangeable, but I could be wrong. What I know is that they both break in Safari. So I’m still looking for a non-breaking thin space that does not break. And I’d like to know why the allegedly non-breaking thin space displays differently in macOS and iOS. On iOS devices, it’s indistinguishable from no-space.

[For collectors only: the ordinary non-breaking space is  . And if anyone wants to asks, “Who cares?” — I do.]