set plotlyServerUrl default to blank string

Author: archmoj

src/plot_api/plot_config.js

@@ -32,7 +32,7 @@ var configAttributes = {
 
     plotlyServerURL: {
         valType: 'string',
-        dflt: 'https://plot.ly',
+        dflt: '',
         description: [
             'Sets base URL for the \'Edit in Chart Studio\' (aka sendDataToCloud) mode bar button',
             'and the showLink/sendData on-graph link'
@@ -261,10 +261,10 @@ var configAttributes = {
         dflt: false,
         description: [
             'Should we include a ModeBar button, labeled "Edit in Chart Studio",',
-            'that sends this chart to plot.ly or another plotly server as specified',
-            'by `plotlyServerURL` for editing, export, etc? Prior to version 1.43.0',
+            'that sends this chart to plotly.com (formerly plot.ly) or another plotly server',
+            'as specified by `plotlyServerURL` for editing, export, etc? Prior to version 1.43.0',
             'this button was included by default, now it is opt-in using this flag.',
-            'Note that this button can (depending on `plotlyServerURL`) send your data',
+            'Note that this button can (depending on `plotlyServerURL` being set) send your data',
             'to an external server. However that server does not persist your data',
             'until you arrive at the Chart Studio and explicitly click "Save".'
         ].join(' ')

test/jasmine/tests/config_test.js

@@ -501,13 +501,30 @@ describe('config argument', function() {
 
         afterEach(destroyGraphDiv);
 
-        it('should default to plotly cloud', function(done) {
+        it('should not default to an external plotly cloud', function(done) {
             Plotly.plot(gd, [], {})
             .then(function() {
-                expect(gd._context.plotlyServerURL).toBe('https://plot.ly');
+                expect(gd._context.plotlyServerURL).not.toBe('https://plot.ly');
+                expect(gd._context.plotlyServerURL).not.toBe('https://plotly.com');
+                expect(gd._context.plotlyServerURL).toBe('');
 
                 Plotly.Plots.sendDataToCloud(gd);
-                expect(form.action).toBe('https://plot.ly/external');
+                expect(form.action.substring(0, 17)).toBe('http://localhost:');
+                expect(form.method).toBe('post');
+            })
+            .catch(failTest)
+            .then(done);
+        });
+
+        it('should be able to connect to plotly cloud when set to https://plotly.com', function(done) {
+            Plotly.plot(gd, [], {}, {
+                plotlyServerURL: 'https://plotly.com'
+            })
+            .then(function() {
+                expect(gd._context.plotlyServerURL).toBe('https://plotly.com');
+
+                Plotly.Plots.sendDataToCloud(gd);
+                expect(form.action).toBe('https://plotly.com/external');
                 expect(form.method).toBe('post');
             })
             .catch(failTest)