Do not attempt to re-hover on exiting subplots

src/components/fx/hover.js

@@ -224,24 +224,20 @@ function _hover(gd, evt, subplot, noHoverEvent) {
     for(var i = 0; i < len; i++) {
         var spId = subplots[i];
 
-        // 'cartesian' case
-        var plotObj = plots[spId];
-        if(plotObj) {
+        if(plots[spId]) {
+            // 'cartesian' case
             supportsCompare = true;
-
-            // TODO make sure that fullLayout_plots axis refs
-            // get updated properly so that we don't have
-            // to use Axes.getFromId in general.
-
-            xaArray[i] = Axes.getFromId(gd, plotObj.xaxis._id);
-            yaArray[i] = Axes.getFromId(gd, plotObj.yaxis._id);
-            continue;
+            xaArray[i] = plots[spId].xaxis;
+            yaArray[i] = plots[spId].yaxis;
+        } 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;

src/plots/cartesian/graph_interact.js

@@ -59,7 +59,7 @@ exports.initInteractions = function initInteractions(gd) {
                 // This is on `gd._fullLayout`, *not* fullLayout because the reference
                 // changes by the time this is called again.
                 gd._fullLayout._rehover = function() {
-                    if(gd._fullLayout._hoversubplot === subplot) {
+                    if((gd._fullLayout._hoversubplot === subplot) && gd._fullLayout._plots[subplot]) {
                         Fx.hover(gd, evt, subplot);
                     }
                 };

src/plots/mapbox/mapbox.js

@@ -475,7 +475,7 @@ proto.initFx = function(calcData, fullLayout) {
         self.yaxis.p2c = function() { return evt.lngLat.lat; };
 
         gd._fullLayout._rehover = function() {
-            if(gd._fullLayout._hoversubplot === self.id) {
+            if(gd._fullLayout._hoversubplot === self.id && gd._fullLayout[self.id]) {
                 Fx.hover(gd, evt, self.id);
             }
         };

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';
 
@@ -2607,6 +2641,56 @@ describe('hover updates', function() {
         })
         .then(done);
     });
+
+    it('should not attempt to rehover over exiting subplots', function(done) {
+        spyOn(Fx, 'hover').and.callThrough();
+
+        var data = [
+            {y: [1], hoverinfo: 'y'},
+            {y: [2], hoverinfo: 'y', xaxis: 'x2', yaxis: 'y2'}
+        ];
+
+        var data2 = [
+            {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
+        };
+
+        var gd = createGraphDiv();
+        var onPt2 = [300, 100];
+        var offPt2 = [250, 100];
+
+        Plotly.react(gd, data, layout)
+        .then(function() {
+            assertLabelsCorrect(onPt2, [303, 100], '2', 'after 1st draw [on-pt]');
+            assertLabelsCorrect(offPt2, null, null, 'after 1st draw [off-pt]');
+            expect(Fx.hover).toHaveBeenCalledTimes(2);
+        })
+        .then(function() {
+            var promise = Plotly.react(gd, data2, layout);
+            assertLabelsCorrect(onPt2, null, null, '2', 'before react() resolves [on-pt]');
+            assertLabelsCorrect(offPt2, null, null, 'before react() resolves [off-pt]');
+            // N.B. no calls from Plots.rehover() as x2y2 subplot got removed!
+            expect(Fx.hover).toHaveBeenCalledTimes(2);
+            return promise;
+        })
+        .then(function() {
+            expect(Fx.hover).toHaveBeenCalledTimes(2);
+            assertLabelsCorrect(onPt2, null, null, '2', 'after react() resolves [on-pt]');
+            assertLabelsCorrect(offPt2, null, null, 'after react() resolves [off-pt]');
+            expect(Fx.hover).toHaveBeenCalledTimes(2);
+        })
+        .catch(failTest)
+        .then(done);
+    });
 });
 
 describe('Test hover label custom styling:', function() {

test/jasmine/tests/mapbox_test.js

@@ -1,5 +1,6 @@
 var Plotly = require('@lib');
 var Lib = require('@src/lib');
+var Fx = require('@src/components/fx');
 
 var constants = require('@src/plots/mapbox/constants');
 var supplyLayoutDefaults = require('@src/plots/mapbox/layout_defaults');
@@ -1155,6 +1156,38 @@ describe('@noCI, mapbox plots', function() {
         .then(done);
     }, LONG_TIMEOUT_INTERVAL);
 
+    it('@gl should not attempt to rehover over exiting subplots', function(done) {
+        spyOn(Fx, 'hover').and.callThrough();
+
+        function countHoverLabels() {
+            return d3.select('.hoverlayer').selectAll('g').size();
+        }
+
+        Promise.resolve()
+        .then(function() {
+            return _mouseEvent('mousemove', pointPos, function() {
+                expect(countHoverLabels()).toEqual(1);
+                expect(Fx.hover).toHaveBeenCalledTimes(1);
+                expect(Fx.hover.calls.argsFor(0)[2]).toBe('mapbox');
+                Fx.hover.calls.reset();
+            });
+        })
+        .then(function() { return Plotly.deleteTraces(gd, [0, 1]); })
+        .then(delay(10))
+        .then(function() {
+            return _mouseEvent('mousemove', pointPos, function() {
+                expect(countHoverLabels()).toEqual(0);
+                // N.B. no additional calls from Plots.rehover()
+                // (as 'mapbox' subplot is gone),
+                // just one on the fallback xy subplot
+                expect(Fx.hover).toHaveBeenCalledTimes(1);
+                expect(Fx.hover.calls.argsFor(0)[2]).toBe('xy');
+            });
+        })
+        .catch(failTest)
+        .then(done);
+    }, LONG_TIMEOUT_INTERVAL);
+
     it('@gl should respond drag / scroll / double-click interactions', function(done) {
         var relayoutCnt = 0;
         var doubleClickCnt = 0;