add test for isSafari downloadImag logic

Author: etpinard

src/snapshot/filesaver.js

@@ -38,8 +38,8 @@ function fileSaver(url, name, format) {
         // Safari doesn't allow downloading of blob urls
         if(Lib.isSafari()) {
             var prefix = format === 'svg' ? ',' : ';base64,';
-            document.location.href = 'data:application/octet-stream' + prefix + encodeURIComponent(url);
-            return resolve();
+            helpers.octetStream(prefix + encodeURIComponent(url));
+            return resolve(name);
         }
 
         // IE 10+ (native saveAs)

src/snapshot/helpers.js

@@ -55,6 +55,10 @@ exports.createBlob = function(url, format) {
     }
 };
 
+exports.octetStream = function(s) {
+    document.location.href = 'data:application/octet-stream' + s;
+};
+
 // Taken from https://bl.ocks.org/nolanlawson/0eac306e4dac2114c752
 function fixBinary(b) {
     var len = b.length;

test/jasmine/tests/download_test.js

@@ -1,11 +1,13 @@
 var Plotly = require('@lib/index');
+var Lib = require('@src/lib');
+
+var helpers = require('@src/snapshot/helpers');
+
 var createGraphDiv = require('../assets/create_graph_div');
 var destroyGraphDiv = require('../assets/destroy_graph_div');
-var textchartMock = require('@mocks/text_chart_arrays.json');
 var failTest = require('../assets/fail_test');
 
-var Lib = require('@src/lib');
-
+var textchartMock = require('@mocks/text_chart_arrays.json');
 var LONG_TIMEOUT_INTERVAL = 2 * jasmine.DEFAULT_TIMEOUT_INTERVAL;
 
 describe('Plotly.downloadImage', function() {
@@ -136,6 +138,26 @@ describe('Plotly.downloadImage', function() {
         .catch(failTest)
         .then(done);
     }, LONG_TIMEOUT_INTERVAL);
+
+    it('should produce right output in Safari', function(done) {
+        spyOn(Lib, 'isSafari').and.callFake(function() { return true; });
+        spyOn(helpers, 'octetStream');
+
+        Plotly.plot(gd, textchartMock.data, textchartMock.layout)
+        .then(function() { return Plotly.downloadImage(gd, {format: 'svg'}); })
+        .then(function() { return Plotly.downloadImage(gd, {format: 'png'}); })
+        .then(function() { return Plotly.downloadImage(gd, {format: 'jpeg'}); })
+        .then(function() { return Plotly.downloadImage(gd, {format: 'webp'}); })
+        .then(function() {
+            var args = helpers.octetStream.calls.allArgs();
+            expect(args[0][0].slice(0, 15)).toBe(',%3Csvg%20class', 'format:svg');
+            expect(args[1][0].slice(0, 8)).toBe(';base64,', 'format:png');
+            expect(args[2][0].slice(0, 8)).toBe(';base64,', 'format:jpeg');
+            expect(args[3][0].slice(0, 8)).toBe(';base64,', 'format:webp');
+        })
+        .catch(failTest)
+        .then(done);
+    });
 });
 
 function downloadTest(gd, format) {