Source code
Revision control
Copy as Markdown
Other Tools
// Test when a declarative binding is deleted.
// ES2020, 8.1.1.1.5 SetMutableBinding ( N, V, S )
//
// 1. ...
// 2. If envRec does not have a binding for N, then
// a. ...
// b. Perform envRec.CreateMutableBinding(N, true).
// c. Perform envRec.InitializeBinding(N, V).
// d. Return NormalCompletion(empty).
// 3. ...
// AndAssignExpr
{
let a = 0;
let f = function() {
eval("var a = 1;");
a &&= (delete a, 2);
assertEq(a, 2);
}
f();
assertEq(a, 0);
}
// OrAssignExpr
{
let a = 1;
let f = function() {
eval("var a = 0;");
a ||= (delete a, 2);
assertEq(a, 2);
}
f();
assertEq(a, 1);
}
// CoalesceAssignExpr
{
let a = undefined;
let f = function() {
eval("var a = null;");
a ??= (delete a, 2);
assertEq(a, 2);
}
f();
assertEq(a, undefined);
}
if (typeof reportCompare === "function")
reportCompare(0, 0);