The guard a condition key offers besides a condition on its own value:
ForeignKeyGuard for a foreign key, nothing otherwise.
The guard refuses every operator key. An object literal is checked for
excess properties against the whole union a key accepts, so without this a
target written beside $beginsWith would satisfy the guard member and be
accepted; a key holds a value condition or a guard, never both.
The guard a condition key offers besides a condition on its own value: ForeignKeyGuard for a foreign key, nothing otherwise.
The guard refuses every operator key. An object literal is checked for excess properties against the whole union a key accepts, so without this a
targetwritten beside$beginsWithwould satisfy the guard member and be accepted; a key holds a value condition or a guard, never both.