Type Alias BoxedSymbol

A purposely boxed Symbol object type, e.g., created via Object(Symbol('key')). This works perfectly fine when used as an object's symbol-key.

Consider the following example:

const mySymbolKey = Symbol('key');
const symbolObject = Object(mySymbolKey);

console.log('(mySymbolKey === symbolObject) ...', (mySymbolKey === symbolObject));  // false
console.log('(mySymbolKey == symbolObject) ...', (mySymbolKey == symbolObject));    // true

const myObject = { foo: 'Foo' };
myObject[mySymbolKey] = 'value set by `mySymbolKey`.';
//       ^^^^^^^^^^^

console.log({ myObject }); // { "myObject": { "foo": "Foo", Symbol(key): "value set by `mySymbolKey`." } }
console.log('myObject[symbolObject] ...', myObject[symbolObject]); // 'value set by `mySymbolKey`.'
//           ---------^^^^^^^^^^^^        ---------^^^^^^^^^^^^

myObject[symbolObject] = 'value overwritten by `symbolObject`.';
//       ^^^^^^^^^^^^

console.log({ myObject }); // { "myObject": { "foo": "Foo", Symbol(key): "value overwritten by `symbolObject`." } }
console.log('myObject[mySymbolKey] ...', myObject[mySymbolKey]); // 'value overwritten by `symbolObject`.'
//           ---------^^^^^^^^^^^        ---------^^^^^^^^^^^
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This demonstrates that, although the primitive symbol and its boxed object are not strictly equal (===), their loose equality (==) is enough for them to act as interchangeable property keys.