// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
description: >
Removal of lexical environment to serve as a temporal dead zone for the
statement's AssignmentExpresson
info: |
IterationStatement : for ( ForDeclaration of AssignmentExpression ) Statement
1. Let keyResult be the result of performing ?
ForIn/OfHeadEvaluation(BoundNames of ForDeclaration,
AssignmentExpression, iterate).
[...]
13.7.5.12 Runtime Semantics: ForIn/OfHeadEvaluation
[...]
2. If TDZnames is not an empty List, then
a. Assert: TDZnames has no duplicate entries.
b. Let TDZ be NewDeclarativeEnvironment(oldEnv).
c. Let TDZEnvRec be TDZ's EnvironmentRecord.
d. For each string name in TDZnames, do
i. Perform ! TDZEnvRec.CreateMutableBinding(name, false).
e. Set the running execution context's LexicalEnvironment to TDZ.
3. Let exprRef be the result of evaluating expr.
4. Set the running execution context's LexicalEnvironment to oldEnv.
[...]
features: [let]
---*/
let x = 'outside';
var probeDecl, probeExpr, probeBody;
for (
let [x, _ = probeDecl = function() { return x; }]
in
{ i: probeExpr = function() { typeof x; } }
)
probeBody = function() { return x; };
assert.throws(ReferenceError, probeExpr);
assert.sameValue(probeDecl(), 'i', 'reference from ForDeclaration');
assert.sameValue(probeBody(), 'i', 'reference from statement body');