test: handle trace with no points, resulting in invisible trace and node3 undefined

Author: monfera

src/traces/choropleth/select.js

@@ -47,7 +47,7 @@ module.exports = function selectPoints(searchInfo, polygon) {
     }
 
     if(node3) {
-        node3.selectAll('path').style('opacity', function (d) {
+        node3.selectAll('path').style('opacity', function(d) {
             return d.dim ? DESELECTDIM : 1;
         });
     }

test/jasmine/tests/select_test.js

@@ -687,6 +687,12 @@ describe('Test select box and lasso per trace:', function() {
         fig.layout.dragmode = 'select';
         fig.layout.geo.scope = 'europe';
 
+        // add a trace with no locations which will then make trace invisible, lacking DOM elements
+        fig.data.push(Lib.extendDeep({}, fig.data[0]));
+        fig.data[1].text = [];
+        fig.data[1].locations = [];
+        fig.data[1].z = [];
+
         Plotly.plot(gd, fig)
         .then(function() {
             return _run(