Shouldn't initialising a object prop with undefined fallback to its default?

[ruiramos]

Hey all,
Unlike all other types of props, if you initialise an object property that has a defined default value with undefined, the default value is not used and the object is set to null.

Example: http://requirebin.com/?gist=dda59c50c9326e84064b

Not sure if this a bug or by design but it does feel a bit weird.

This happens because undefined objects are converted null in the dataTypes object definition:
(lines 645, object.set)

if (newType !== 'object' && _.isUndefined(newVal)) {
    newVal = null;
    newType = 'object';
}

... but properties only gets the default value if the value is not undefined:
(lines 551 Object.defineProperty.get)

if (typeof result !== 'undefined') { 
    (...)
    return result
}

We could easily fix this by changing that first null to undefined so that undefined objects keep their undefined value, although I don't know if that would have any side effects in other parts of the code.

Thanks !
Rui

[cdaringe]

Hey @ruiramos. Clear fiddle. I agree, it does not produce naturally expected results.
This was a pretty early commit in the project that @HenrikJoreteg committed back in May last year. There are checks against null in the codebase which appear to be dependent on that null being set. Maybe you can test updating said checks and the blocks you pointed out, add test or two, and run the test suite?