do not delete hoverlabel when hovertemplate is defined

[antoinerg]

Closes#3478

[etpinard]

Nice!

It might be nice to add a few more test cases 🔒 ing down this fix. Maybe one for scattergeo, one for scatterpolar, one for scatterternary and one scattermapbox? That is, one test for each subtype type supported by hovertemplate.

[antoinerg]

Just for future reference, problem #3418 fixed by the current PR will arise for any trace types that do not append anything to variable text after going through:

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

Lines 934 to 965 in 58bf5bb

	if(d.zLabel!==undefined){
	if(d.xLabel!==undefined)text+='x: '+d.xLabel+'<br>';
	if(d.yLabel!==undefined)text+='y: '+d.yLabel+'<br>';
	text+=(text ? 'z: ' : '')+d.zLabel;
	}
	elseif(showCommonLabel&&d[hovermode+'Label']===t0){
	text=d[(hovermode==='x' ? 'y' : 'x')+'Label']||'';
	}
	elseif(d.xLabel===undefined){
	if(d.yLabel!==undefined)text=d.yLabel;
	}
	elseif(d.yLabel===undefined)text=d.xLabel;
	elsetext='('+d.xLabel+', '+d.yLabel+')';
	if((d.text||d.text===0)&&!Array.isArray(d.text)){
	text+=(text ? '<br>' : '')+d.text;
	}
	// used by other modules (initially just ternary) that
	// manage their own hoverinfo independent of cleanPoint
	// the rest of this will still apply, so such modules
	// can still put things in (x|y|z)Label, text, and name
	// and hoverinfo will still determine their visibility
	if(d.extraText!==undefined)text+=(text ? '<br>' : '')+d.extraText;
	// if 'text' is empty at this point,
	// put 'name' in main label and don't show secondary label
	if(text===''){
	// if 'name' is also empty, remove entire label
	if(name==='')g.remove();
	text=name;
	}

[etpinard]

@antoinerg can you try to add tests for scatterternary and scattermapbox at some point today? I'd like to include this PR in today's (or tomorrow's 😏 ) v1.44.2. Thanks!

[antoinerg]

@antoinerg can you try to add tests for scatterternary and scattermapbox at some point today? I'd like to include this PR in today's (or tomorrow's ) v1.44.2. Thanks!

This is now done in 7bff254. Sorry for the slow reply: I initially struggled to reproduce the issue for scatterternary and scattermapbox before realizing the existing tests didn't actually check the content or the existence of hover labels on the page.

[etpinard]

Thanks 💃 !