1135167 - Invalid scoping in «for (let i in/of expr)» blocks.

Status: RESOLVED DUPLICATE of bug 1069480

(Core :: JavaScript Engine, defect)

Description

[Сковорода Никита]

Attachment: #jsapi irc log

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.111 Safari/537.36

Steps to reproduce:

1) var i = [1, 2, 3]; for (let i of i) console.log(i);
2) var i = [1, 2, 3]; for (let i in i) console.log(i);
3) for (let i in/of a[i]/f[i]), anything where «expr» depends on «i».


Actual results:

1) 1 2 3
2) 0 1 2
3) When evaluting «expr», «i» is taken from outside of the scope.


Expected results:

1) Exception
2) Exception
3) Exception

See https://people.mozilla.org/~jorendorff/es6-draft.html#sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind-labelset

Comment 1

[Сковорода Никита]

Validated only in nightly-37, after updating to nightly-38 firefox somewhy fails to launch, so I can't check 38 now.

Comment 2

[Сковорода Никита]

Just verified in 38.0a1 (2015-02-20).