1453710 - Object.keys(localStorage) misses keys named "key" (same with sessionStorage)

Status: RESOLVED INVALID

(Core :: DOM: Core & HTML, defect, P2)

Description

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

STR:
localStorage.setItem("key", "value1")
localStorage.setItem("key2", "value2")
Object.keys(localStorage) // Only lists key2

Same issue with sessionStorage but other objects are okay.

Of course, localStorage.getItem("key") returns "value1".

Comment 1

[Mike Ratcliffe [:miker] [:mratcliffe] [:mikeratcliffe]]

This is because "key" is a method on the prototype.

localStorage.setItem("setItem", "value3") would cause a similar issue.

Comment 2

[Liqueur Librazy]

localStorage.setItem("clear", "value")
localStorage.setItem("constructor", "value")
Object.keys(localStorage) // There are neither "clear" nor "constructor" here. Same to all the properties that are on the prototype chain of localStorage.

Comment 3

[Liqueur Librazy]

Are there any specification about this behavior? IMO, the keys in Storage should be enumerable properties of it no matter whether the key can be found in prototype chain, and should be listed in Object.keys().

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

I think the following example helps to understand this
https://heycam.github.io/webidl/#example-9317c76c

https://heycam.github.io/webidl/#OverrideBuiltins
https://html.spec.whatwg.org/multipage/webstorage.html#the-storage-interface

But I don't know why OverrideBuiltins isn't use here.
File a spec bug if you want to change the behavior?
(though, I guess at least localStorage is somewhat deprecated, so not sure why that would need to be changed.)

Comment 5

[Liqueur Librazy]

https://github.com/whatwg/html/issues/183 It is discussed before and this behavior conforms to the spec. I'll do some cross-browser test and reopen the issue if majority of browsers threats localStorage as [OverrideBuiltins].