fix(ios): updated Ti.Blob.toString() behaviour to original (#11421)

Fixes TIMOB-27350

common/Resources/ti.internal/extensions/ti/ti.blob.js

@@ -9,6 +9,7 @@ if (Ti.Platform.osname === 'iphone' || Ti.Platform.osname === 'ipad') {
 	const buffer = Ti.createBuffer({ value: '' });
 	const blob = buffer.toBlob();
 	blob.constructor.prototype.toString = function () {
-		return this.text;
+		const value = this.text;
+		return (value === undefined) ? '[object TiBlob]' :  value;
 	};
 }

tests/Resources/ti.blob.addontest.js

@@ -0,0 +1,30 @@
+/*
+ * Appcelerator Titanium Mobile
+ * Copyright (c) 2011-Present by Appcelerator, Inc. All Rights Reserved.
+ * Licensed under the terms of the Apache Public License
+ * Please see the LICENSE included with this distribution for details.
+ */
+/* eslint-env mocha */
+/* eslint no-unused-expressions: "off" */
+'use strict';
+const should = require('./utilities/assertions');
+
+describe('Titanium.Blob', function () {
+	describe('#toString()', function () {
+		it('binary content', function () {
+			const blob = Ti.Filesystem.getFile('SmallLogo.png').read();
+			should(blob.toString()).eql('[object TiBlob]');
+		});
+
+		it('empty string', function () {
+			const blob = Ti.createBuffer({ value: '' }).toBlob();
+			should(blob.toString()).eql('');
+		});
+
+		it('text content', function () {
+			const blob = Ti.createBuffer({ value: 'test toString()' }).toBlob();
+			should(blob.toString()).eql('test toString()');
+		});
+
+	});
+});