test262/test/language/statements/with/unscopables-not-referenced-for-undef.js

// Copyright 2015 Mike Pennisi. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
esid: sec-getidentifierreference
es6id: 8.1.2.1
description: >
  `Symbol.unscopables` is not referenced when environment record does not have
  requested property
info: |
  [...]
  2. Let envRec be lex's EnvironmentRecord.
  3. Let exists be ? envRec.HasBinding(name).

  8.1.1.2.1 HasBinding

  1. Let envRec be the object Environment Record for which the method was
     invoked.
  2. Let bindings be the binding object for envRec.
  3. Let foundBinding be ? HasProperty(bindings, N).
  4. If foundBinding is false, return false.

  13.11.7 (The `with` Statement) Runtime Semantics: Evaluation

  [...]
  5. Set the withEnvironment flag of newEnv’s EnvironmentRecord to true.
  [...]
flags: [noStrict]
features: [Symbol.unscopables]
---*/

var x = 0;
var env = {};
var callCount = 0;
Object.defineProperty(env, Symbol.unscopables, {
  get: function() {
    callCount += 1;
  }
});

with (env) {
  x;
}

assert.sameValue(callCount, 0);