warn + exit early when Fx.hover is called w/ unrecognized subplot id

Author: etpinard

src/components/fx/hover.js

@@ -235,13 +235,15 @@ function _hover(gd, evt, subplot, noHoverEvent) {
 
             xaArray[i] = Axes.getFromId(gd, plotObj.xaxis._id);
             yaArray[i] = Axes.getFromId(gd, plotObj.yaxis._id);
-            continue;
+        } else if(fullLayout[spId] && fullLayout[spId]._subplot) {
+            // other subplot types
+            var _subplot = fullLayout[spId]._subplot;
+            xaArray[i] = _subplot.xaxis;
+            yaArray[i] = _subplot.yaxis;
+        } else {
+            Lib.warn('Unrecognized subplot: ' + spId);
+            return;
         }
-
-        // other subplot types
-        var _subplot = fullLayout[spId]._subplot;
-        xaArray[i] = _subplot.xaxis;
-        yaArray[i] = _subplot.yaxis;
     }
 
     var hovermode = evt.hovermode || fullLayout.hovermode;

test/jasmine/tests/hover_label_test.js

@@ -36,6 +36,41 @@ function touch(path, options) {
     return;
 }
 
+describe('Fx.hover:', function() {
+    var gd;
+
+    beforeEach(function() { gd = createGraphDiv(); });
+
+    afterEach(destroyGraphDiv);
+
+    it('should warn when passing subplot ids that are not part of the graph', function(done) {
+        spyOn(Lib, 'warn');
+
+        var data = [
+            {y: [1], hoverinfo: 'y'}
+        ];
+
+        var layout = {
+            xaxis: {domain: [0, 0.5]},
+            xaxis2: {anchor: 'y2', domain: [0.5, 1]},
+            yaxis2: {anchor: 'x2'},
+            width: 400,
+            height: 200,
+            margin: {l: 0, t: 0, r: 0, b: 0},
+            showlegend: false
+        };
+
+        Plotly.plot(gd, data, layout)
+        .then(function() {
+            Fx.hover(gd, {xpx: 300, ypx: 100}, 'x2y2');
+            expect(gd._hoverdata).toBe(undefined, 'did not generate hoverdata');
+            expect(Lib.warn).toHaveBeenCalledWith('Unrecognized subplot: x2y2');
+        })
+        .catch(failTest)
+        .then(done);
+    });
+});
+
 describe('hover info', function() {
     'use strict';
 
@@ -2150,7 +2185,6 @@ describe('hover info on stacked subplots', function() {
     });
 });
 
-
 describe('hover on many lines+bars', function() {
     'use strict';