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  • [[DefineOwnProperty]] (P, Desc)

[[DefineOwnProperty]] (P, Desc)

# Axel Rauschmayer (10 years ago)

people.mozilla.org/~jorendorff/es6-draft.html#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc

Quote (note typo in second item):

  1. A property cannot be added as or modified to be non-configurable, if it does not exists as a non-configurable own property of the target object.

  2. A property may not be non-configurable, if is corresponding configurable property of the target object exists.

Question: Doesn’t #1 imply #2?

# Tom Van Cutsem (10 years ago)

2014-11-27 12:05 GMT+01:00 Axel Rauschmayer <axel at rauschma.de>:

people.mozilla.org/~jorendorff/es6-draft.html#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc

Quote (note typo in second item):

  1. A property cannot be added as or modified to be non-configurable, if it does not exists as a non-configurable own property of the target object.

  2. A property may not be non-configurable, if is corresponding configurable property of the target object exists.

Question: Doesn’t #1 imply #2?

Hmm, I think you're right. It seems to me that #2 is more an invariant of [[GetOwnProperty]] than of [[DefineOwnProperty]]. Perhaps it's just a copy-paste remnant. Allen, can you clarify what you had in mind?