v8/test/mjsunit/es6/block-eval-var-over-legacy-const.js
littledan 95145fa826 Ship ES2015 sloppy-mode const semantics
This patch moves the semantics of 'const' in sloppy mode to match those
in strict mode, that is, const makes lexical (let-like) bindings, must
have an initializer, and does not create properties of the global object.

R=adamk
LOG=Y
BUG=v8:3305
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1571873004

Cr-Commit-Position: refs/heads/master@{#33218}
2016-01-11 23:09:59 +00:00

87 lines
1.6 KiB
JavaScript

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --harmony-sloppy --harmony-sloppy-let --harmony-sloppy-function
// Flags: --legacy-const
// Legacy-const-let conflict in a function throws, even if the legacy const
// is in an eval
// Throws at the top level of a function
assertThrows(function() {
let x = 1;
eval('const x = 2');
}, TypeError);
// If the eval is in its own block scope, throws
assertThrows(function() {
let y = 1;
{ eval('const y = 2'); }
}, TypeError);
// If the let is in its own block scope, with the eval, throws
assertThrows(function() {
{
let x = 1;
eval('const x = 2');
}
}, TypeError);
// Legal if the let is no longer visible
assertDoesNotThrow(function() {
{
let x = 1;
}
eval('const x = 2');
});
// In global scope
let caught = false;
try {
let z = 1;
eval('const z = 2');
} catch (e) {
caught = true;
}
assertTrue(caught);
// Let declarations beyond a function boundary don't conflict
caught = false;
try {
let a = 1;
(function() {
eval('const a');
})();
} catch (e) {
caught = true;
}
assertFalse(caught);
// legacy const across with doesn't conflict
caught = false;
try {
(function() {
with ({x: 1}) {
eval("const x = 2;");
}
})();
} catch (e) {
caught = true;
}
assertFalse(caught);
// legacy const can still conflict with let across a with
caught = false;
try {
(function() {
let x;
with ({x: 1}) {
eval("const x = 2;");
}
})();
} catch (e) {
caught = true;
}
assertTrue(caught);