src/third_party/mozjs-45/js/src/jit-test/tests/truthiness/equal-undefined.js

function f(v, value)
{
  var b = v == undefined;
  assertEq(b, value,
           "failed: " + v + " " + value);
}

f({}, false);
f({}, false);
f(null, true);
f(null, true);
f(undefined, true);
f(undefined, true);
f(objectEmulatingUndefined(), true);
f(objectEmulatingUndefined(), true);
f(Object.prototype, false);
f(Object.prototype, false);

function g(v, value)
{
  var b = v == undefined;
  assertEq(b, value,
           "failed: " + v + " " + value);
}

g({}, false);
g({}, false);

function h(v, value)
{
  var b = v == undefined;
  assertEq(b, value,
           "failed: " + v + " " + value);
}

h(objectEmulatingUndefined(), true);
h(objectEmulatingUndefined(), true);