sankey: test to 🔒 down grouping via mouse selection

Author: antoinerg

src/traces/sankey/base_plot.js

@@ -57,6 +57,8 @@ function subplotUpdateFx(gd, index) {
     var cursor = fullLayout.dragmode === 'pan' ? 'move' : 'crosshair';
     var bgRect = trace._bgRect;
 
+    if(dragMode === 'pan' || dragMode === 'zoom') return;
+
     setCursor(bgRect, cursor);
 
     var xaxis = {

test/jasmine/tests/select_test.js

@@ -2666,6 +2666,47 @@ describe('Test select box and lasso per trace:', function() {
         .catch(failTest)
         .then(done);
     });
+
+    it('@flaky should work on sankey traces', function(done) {
+        var fig = Lib.extendDeep({}, require('@mocks/sankey_circular.json'));
+        fig.layout.dragmode = 'select';
+        var dblClickPos = [250, 400];
+        var opts = {};
+
+        Plotly.plot(gd, fig)
+        .then(function() {
+            // No groups initially
+            expect(gd._fullData[0].node.groups).toEqual([]);
+
+            opts.element = document.elementFromPoint(400, 400);
+        })
+        .then(function() {
+            // Grouping the two nodes on the top right
+            return _run(
+                [[640, 130], [400, 450]],
+                function() {
+                    expect(gd._fullData[0].node.groups).toEqual([[2, 3]]);
+                },
+                dblClickPos, BOXEVENTS, 'for top right nodes #2 and #3'
+            );
+        })
+        .then(function() {
+            // Grouping node #4 and the previous group
+            drag([[715, 400], [300, 110]], opts);
+        })
+        .then(function() {
+            expect(gd._fullData[0].node.groups).toEqual([[4, 3, 2]]);
+        })
+        .then(function() {
+            // Grouping node #0 and #1 on the left side
+            drag([[160, 110], [200, 590]], opts);
+        })
+        .then(function() {
+            expect(gd._fullData[0].node.groups).toEqual([[4, 3, 2], [0, 1]]);
+        })
+        .catch(failTest)
+        .then(done);
+    });
 });
 
 describe('Test that selections persist:', function() {