[TIMOB-26179] iOS: Property check on proxy always returns true

GitHub Issue	n/a
Type	Bug
Priority	Critical
Status	Closed
Resolution	Fixed
Resolution Date	2018-08-24T17:24:12.000+0000
Affected Version/s	Release 7.2.0
Fix Version/s	Release 7.5.0
Components	iOS
Labels	n/a
Reporter	Jan Vennemann
Assignee	Jan Vennemann
Created	2018-07-03T12:23:29.000+0000
Updated	2019-04-26T19:03:53.000+0000

Description

Checking for property existence on Titanium proxy objects always returns true, ignoring if a property really exists or not. Various aspects of Vue/Angular and module bundling with Rollup/Webpack rely on proper existence checks for properties on our proxies. *Steps to reproduce the behavior* Run the following example code in a Titanium app which compares the behavior to a plain JavaScript object.

const win = Ti.UI.createWindow();
const plainObject = {
	prop: 'bar',
	func: () => {}
};

Ti.API.debug('### hasProperty check ###');
Ti.API.debug('non-existing property');
Ti.API.debug(proxy: ${'foo' in win});
Ti.API.debug(plain: ${'foo' in plainObject});
Ti.API.debug('existing property');
Ti.API.debug(proxy: ${'children' in win});
Ti.API.debug(plain: ${'prop' in plainObject});

*Actual behavior* The property check returns true for non-existing properties on the Ti.UI.Window object. *Expected behavior* The property check should return true only for existing properties and false otherwise.

Comments

Jan Vennemann 2018-07-03

PR: https://github.com/appcelerator/titanium_mobile/pull/10150

Samir Mohammed 2018-07-18

*Closing ticket*, Verified fix in SDK Version: 7.4.0.v20180717131401 *FR Passed (Test Steps):*

Created a titanium Application

Added the following code in the description in to the `app.js`

Ran the program

Following was seen in the console (Proxy for non-existing property no longer always set to true):

   [DEBUG] :  ### hasProperty check ###
   [DEBUG] :  non-existing property
   [DEBUG] :  proxy: false
   [DEBUG] :  plain: false
   [DEBUG] :  existing property
   [DEBUG] :  proxy: true
   [DEBUG] :  plain: true

*Test Environment*

   APPC Studio: 5.0.0.201712081732
   APPC CLI: 7.0.4
   iPhone 6 simulator (11.2)
   Operating System Name: Mac OS High Sierra
   Operating System Version: 10.13
   Node.js Version: 8.9.1
   Xcode 9.2

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