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// When obj[@@unscopables].x changes, bindings appear and disappear accordingly.
let x = "global";
function getX() { return x; }
let unscopables = {x: true};
let obj = {x: "obj", [Symbol.unscopables]: unscopables};
with (obj) {
assertEq(x, "global");
x = "global-1";
assertEq(x, "global-1");
assertEq(obj.x, "obj");
unscopables.x = false; // suddenly x appears in the with-environment
assertEq(x, "obj");
x = "obj-1";
assertEq(getX(), "global-1"); // unchanged
assertEq(obj.x, "obj-1");
unscopables.x = true; // *poof*
assertEq(x, "global-1");
x = "global-2";
assertEq(getX(), "global-2");
assertEq(obj.x, "obj-1"); // unchanged
// The determination of which binding is assigned happens when the LHS of
// assignment is evaluated, before the RHS. This is observable if we make
// the binding appear or disappear during evaluation of the RHS, before
// assigning.
x = (unscopables.x = false, "global-3");
assertEq(getX(), "global-3");
assertEq(obj.x, "obj-1");
x = (unscopables.x = true, "obj-2");
assertEq(getX(), "global-3");
assertEq(obj.x, "obj-2");
}
assertEq(x, "global-3");
reportCompare(0, 0);
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