Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2015 Mike Pennisi. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
es6id: 8.1.1.2.1
description: >
True-coercing `Symbol.unscopables` properties block access to object environment record
info: |
[...]
6. If the withEnvironment flag of envRec is false, return true.
7. Let unscopables be Get(bindings, @@unscopables).
8. ReturnIfAbrupt(unscopables).
9. If Type(unscopables) is Object, then
a. Let blocked be ToBoolean(Get(unscopables, N)).
b. ReturnIfAbrupt(blocked).
c. If blocked is true, return false.
ES6: 13.11.7 (The `with` Statement) Runtime Semantics: Evaluation
[...]
6. Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
[...]
flags: [noStrict]
features: [Symbol.unscopables]
---*/
var x = 0;
var env = { x: 1 };
env[Symbol.unscopables] = { x: true };
with (env) {
assert.sameValue(x, 0, 'literal `true` value');
}
env[Symbol.unscopables].x = 'string';
with (env) {
assert.sameValue(x, 0, 'non-empty string values');
}
env[Symbol.unscopables].x = 86;
with (env) {
assert.sameValue(x, 0, 'non-zero number values');
}
env[Symbol.unscopables].x = {};
with (env) {
assert.sameValue(x, 0, 'object values');
}
env[Symbol.unscopables].x = Symbol.unscopables;
with (env) {
assert.sameValue(x, 0, 'Symbol values');
}
reportCompare(0, 0);