stringToBlob method extracted

frontend-js/src/test/js/gui/AddOverlayDialog-test.js

 "use strict";
 
-var Readable = require('stream').Readable;
-var toBlob = require('stream-to-blob');
-
 require("../mocha-config");
 var $ = require('jquery');
 
@@ -64,7 +61,6 @@ describe('AddOverlayDialog', function () {
   describe('processFile', function () {
     it('set default type', function () {
       var dialog;
-      var file;
       return ServerConnector.getProject().then(function (project) {
         dialog = createDialog(project);
         return dialog.init();
@@ -73,19 +69,8 @@ describe('AddOverlayDialog', function () {
         dialog.setType("GENETIC_VARIANT");
         assert.equal("GENETIC_VARIANT", dialog.getType());
 
-        var stream = new Readable;
-        stream.push("s1\n");
-        stream.push(null);
-
-        return new Promise(function (resolve, reject) {
-          toBlob(stream, function (err, blob) {
-            if (err) return reject(err.message);
-            file = blob;
-            file.name = "test.txt";
-            resolve(blob);
-          })
-        });
-      }).then(function () {
+        return helper.stringToBlob("s1\n");
+      }).then(function (file) {
         return dialog.processFile(file);
       }).then(function () {
         assert.equal("GENERIC", dialog.getType());

frontend-js/src/test/js/helper.js

 "use strict";
 
+var Readable = require('stream').Readable;
+var toBlob = require('stream-to-blob');
+
 require("./mocha-config");
 var $ = require('jquery');
 
@@ -643,6 +646,25 @@ Helper.prototype.createGoogleCanvas = function () {
   });
 };
 
+/**
+ *
+ * @param {string} content
+ * @return {Promise<Blob>}
+ */
+Helper.prototype.stringToBlob = function (content) {
+  var stream = new Readable;
+  stream.push(content);
+  stream.push(null);
+
+  return new Promise(function (resolve, reject) {
+    toBlob(stream, function (err, blob) {
+      if (err) return reject(err.message);
+      blob.name = "test.txt";
+      resolve(blob);
+    })
+  });
+};
+
 /**
  *
  * @type {number}