add double click test

Author: etpinard

test/jasmine/tests/click_test.js

@@ -1,5 +1,6 @@
 var Plotly = require('@lib/index');
 var Lib = require('@src/lib');
+var DBLCLICKDELAY = require('@src/plots/cartesian/constants').DBLCLICKDELAY;
 
 var createGraphDiv = require('../assets/create_graph_div');
 var destroyGraphDiv = require('../assets/destroy_graph_div');
@@ -22,6 +23,14 @@ describe('click event', function() {
         mouseEvent('mouseup', clientX, clientY);
     }
 
+    function doubleClick(cb) {
+        click();
+        setTimeout(function() {
+            click();
+            cb();
+        }, DBLCLICKDELAY / 2);
+    }
+
     beforeEach(function(done) {
         gd = createGraphDiv();
 
@@ -51,8 +60,16 @@ describe('click event', function() {
         expect(pt.y).toEqual(2.125);
     });
 
+    it('should trigger double click if two clicks are \'close\' together', function(done) {
+        var futureData;
 
+        gd.on('plotly_doubleclick', function(data) {
+            futureData = data;
+        });
 
+        doubleClick(function() {
+            expect(futureData).toBe(null);
+            done();
         });
     });
 });