Bug 54289 – Object.defineProperty does not override existing properties

• Component: JavaScriptCore
• Status: RESOLVED WORKSFORME

[Jürg Lehni]

Even if configurable: true was provided at definition time:

var obj = {};

Object.defineProperty(obj, 'test', { value: 10, configurable: true });

alert(obj.test); // 10

Object.defineProperty(obj, 'test', { value: 20, configurable: true });

alert(obj.test); // Should be 20, is still 10

The workaround is to call delete before the 2nd definition:

delete obj.test;

But it seems this contradicts the specifications. Or am I misinterpreting them?

[Jürg Lehni]

Created attachment 82140 [details]
Code to replicate behavior.

[Jürg Lehni]

Here the link to the same bug over at the Chromium site:

http://code.google.com/p/chromium/issues/detail?id=72736

[Gavin Barraclough]

This works in ToT, a lot of defineOwnProperty bugs were fixed lately so it'll be hard to track down exactly which revision!  Please reopen if you are still seeing any issues.

cheers, G.