Pattern: Missing use of case clause
Issue: -
Switching on instances of enum-like classes should be exhaustive.
Enum-like classes are defined as concrete (non-abstract) classes that have:
- only private non-factory constructors
- two or more static const fields whose type is the enclosing class and
- no subclasses of the class in the defining library
DO define case clauses for all constants in enum-like classes.
Example of incorrect code:
class EnumLike {
final int i;
const E._(this.i);
static const e = E._(1);
static const f = E._(2);
static const g = E._(3);
}
void bad(EnumLike e) {
// Missing case.
switch(e) { // LINT
case E.e :
print('e');
break;
case E.f :
print('e');
break;
}
}Example of correct code:
class EnumLike {
final int i;
const E._(this.i);
static const e = E._(1);
static const f = E._(2);
static const g = E._(3);
}
void ok(E e) {
// All cases covered.
switch(e) { // OK
case E.e :
print('e');
break;
case E.f :
print('e');
break;
case E.g :
print('e');
break;
}
}