v8/test/mjsunit/regress/regress-799761.js

// Copyright 2008 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
// met:
//
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//
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// Flags: --legacy-const

// const variables should be read-only
const c = 42;
c = 87;
assertEquals(42, c);


// const variables are not behaving like other JS variables when it comes
// to scoping - in fact they behave more sanely. Inside a 'with' they do
// not interfere with the 'with' scopes.

(function () {
  with ({ x: 42 }) {
    const x = 7;
  }
  x = 5;
  assertEquals(7, x);
})();


// const variables may be declared but never initialized, in which case
// their value is undefined.

(function (sel) {
  if (sel == 0)
    with ({ x: 42 }) {
    const x;
    }
  else
    x = 3;
  x = 5;
  assertTrue(typeof x == 'undefined');
})(1);


// const variables may be initialized to undefined.
(function () {
  with ({ x: 42 }) {
    const x = undefined;
  }
  x = 5;
  assertTrue(typeof x == 'undefined');
})();


// const variables may be accessed in inner scopes like any other variable.
(function () {
  function bar() {
    assertEquals(7, x);
  }
  with ({ x: 42 }) {
    const x = 7;
  }
  x = 5
  bar();
})();


// const variables may be declared via 'eval'
(function () {
  with ({ x: 42 }) {
    eval('const x = 7');
  }
  x = 5;
  assertEquals(7, x);
})();