toString method
The enum's own toString override when the script declares one, and
EnumName.valueName otherwise.
SCE116. The DEFAULT was already right — which is why this was easy to
miss: P.a is what a host wants and what Dart prints, so nothing looked
broken until a script overrode toString and the override was ignored.
Implementation
@override
String toString() => renderInterpretedToString(
target: this,
method: parentEnum.findInstanceMethod('toString'),
visitor: parentEnum.declaringVisitor,
fallback: () => '${parentEnum.name}.$name',
);