934309 - Web Audio Node properties don't respond to "hasOwnProperty"

Status: RESOLVED INVALID

(Core :: Web Audio, defect)

Description

[stuartmemo]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1690.2 Safari/537.36

Steps to reproduce:

Create oscillator like so...

var context = new AudioContext(),
    osc = context.createOscillator;

console.log(osc.context);
console.log(osc.hasOwnProperty('context');



Actual results:

console.log(osc.context); // logs context.
console.log(osc.hasOwnProperty('context')); // returns false


Expected results:

osc.hasOwnProperty('context') should return true as context property exists.

Comment 1

[stuartmemo]

Typos sorry, corrected code...

var context = new AudioContext(),
    osc = context.createOscillator();

console.log(osc.context);
console.log(osc.hasOwnProperty('context'));

Comment 2

[Karl Tomlinson (:karlt)]

|context| is a property of AudioNode.
Is hasOwnProperty('context') meant to return true for objects with derived interfaces?

Comment 3

[stuartmemo]

I believe hasOwnProperty should work regardless of the object. The fact that it's an object with that property is enough. Might be wrong though!

Comment 4

[Karl Tomlinson (:karlt)]

See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty#Example:_Direct_versus_inherited_properties

If osc.hasOwnProperty('type') returns true, then this is probably intended behavior.

Comment 5

[Karl Tomlinson (:karlt)]

Looking at that example, I don't even know whether osc.hasOwnProperty('type') should return true.

Comment 6

[stuartmemo]

I believe it should. I think it would be different if I were to create the oscillator node and have it inherit the properties of AudioNode in JavaScript. Because such nodes are native to the browser, hasOwnProperty('whatever') should return true.

Comment 7

[Masatoshi Kimura [:emk]]

No, the Web IDL spec is very clear about that. 
Why don't you use ('whatever' in osc)?

Comment 8

[stuartmemo]

Is this because osc.context can't be changed on creation of the oscillator?

Yeah, I can easily get around this, I just thought it was a bug as it behaves differently in Chrome. Will raise a bug over there :)