Fixes allowedFileType JS problem with unit test

src/Umbraco.Web.UI.Client/test/unit/common/services/media-helper.spec.js

@@ -0,0 +1,39 @@
+describe('mediaHelper service tests', function () {
+    var mediaHelper;
+
+    beforeEach(module('umbraco.services'));
+
+    beforeEach(inject(function ($injector) {
+        mediaHelper = $injector.get('mediaHelper');
+    }));
+
+    describe('formatFileTypes', function () {
+
+        it('will ignore any empty strings passed as arguments', function () {
+            
+            var result = mediaHelper.formatFileTypes("");
+            expect(result.length).toBe(0);
+
+            result = mediaHelper.formatFileTypes(" ");
+            expect(result.length).toBe(0);
+
+            result = mediaHelper.formatFileTypes("  ");
+            expect(result.length).toBe(0);
+
+            result = mediaHelper.formatFileTypes("  , ");
+            expect(result.length).toBe(0);
+
+            result = mediaHelper.formatFileTypes("  , ,,");
+            expect(result.length).toBe(0);
+
+        });
+
+        it('includes prefixed dot when formatting', function () {
+
+            var result = mediaHelper.formatFileTypes(".jpg, .png, gif");
+            expect(result).toBe(".jpg,.png,.gif");
+
+        });
+
+    });
+});