Zoom: Add test while scrolling

Author: mdtusz

test/jasmine/assets/mouse_event.js

@@ -10,7 +10,14 @@ module.exports = function(type, x, y, opts) {
         fullOpts.buttons = opts.buttons;
     }
 
-    var el = document.elementFromPoint(x, y);
-    var ev = new window.MouseEvent(type, fullOpts);
+    var el = document.elementFromPoint(x, y),
+        ev;
+
+    if(type === 'scroll') {
+        ev = new window.WheelEvent('wheel', opts);
+    } else {
+        ev = new window.MouseEvent(type, fullOpts);
+    }
+
     el.dispatchEvent(ev);
 };

test/jasmine/tests/click_test.js

@@ -711,6 +711,37 @@ describe('Test click interactions:', function() {
         });
     });
 
+    describe('scroll zoom interactions', function() {
+
+        beforeEach(function(done) {
+            Plotly.plot(gd, mockCopy.data, mockCopy.layout, { scrollZoom: true }).then(done);
+        });
+
+        it('zooms in on scroll up', function() {
+
+            var plot = gd._fullLayout._plots.xy.plot;
+
+            mouseEvent('mousemove', 400, 250);
+            mouseEvent('scroll', 400, 250, { deltaX: 0, deltaY: -1000 });
+
+            var transform = plot.attr('transform');
+
+            console.log(transform);
+
+            var mockEl = {
+                attr: function() {
+                    return transform;
+                }
+            };
+
+            var translate = Lib.getTranslate(mockEl),
+                scale = Lib.getScale(mockEl);
+
+            expect([translate.x, translate.y]).toBeCloseToArray([62.841, 99.483]);
+            expect([scale.x, scale.y]).toBeCloseToArray([1.221, 1.221]);
+        });
+    });
+
     describe('pan interactions', function() {
         beforeEach(function(done) {
             mockCopy.layout.dragmode = 'pan';
@@ -745,7 +776,7 @@ describe('Test click interactions:', function() {
             mouseEvent('mousedown', start, start);
             mouseEvent('mousemove', end, end);
 
-            expect(plot.attr('transform')).toBe('translate(250, 280)');
+            expect(plot.attr('transform')).toBe('translate(250, 280) scale(1, 1)');
 
             mouseEvent('mouseup', end, end);
         });