[Bug] <sup> for trace.name is not respected in hoverlabel

[Braintelligence]

Hello everyone.
If you provide a name for your trace containing <sup> it doesn't work for hoverlabels with hoverinfo containing name.

https://codepen.io/anon/pen/aPpmzw

As you can see, the legend is correct but the hoverlabel shows the number as if <sup> was never provided.

[Braintelligence]

Just to make sure: This bug is still true for 1.43.0.

[etpinard]

Thanks for the report

[Braintelligence]

@etpinard Did someone look at this bug yet? 😸 Need to know if this will be fixed within this quarter, so I can refactor some of the plots before we publish them with this bug.

[etpinard]

We currently strip out all pseudo-html tags for trace.name here:

plotly.js/src/components/fx/hover.js

Lines 927 to 937 in 51b5c25

	if(d.name) {
	// strip out our pseudo-html elements from d.name (if it exists at all)
	name = svgTextUtils.plainText(d.name || '');
	var nameLength = Math.round(d.nameLength);
	if(nameLength > -1 && name.length > nameLength) {
	if(nameLength > 3) name = name.substr(0, nameLength - 3) + '...';
	else name = name.substr(0, nameLength);
	}
	}

I don't remember why we do this. Maybe @alexcjohnson remembers?

[alexcjohnson]

I suspect we hadn't bothered figuring out vertical sizing of the name field, also we're often truncating the name and it could be weird to truncate in the middle of some pseudo-html. Probably wouldn't be too hard to resolve these issues and allow pseudo-html there though. I'm a bit concerned about color there though: it would be pretty easy to have colored text in the legend - either part or all of name - that would be ugly or even invisible in the hover label.

[Braintelligence]

Would it be viable to just allow <sup> for now?

EDIT: Truncating in the middle of the pseudo HTML would be really awful, though... This should be fixable by applying agnostic HTML tag regex I guess.