sort_unnamed_constructors_first   
              
Sort unnamed constructor declarations first.
Details
#DO sort unnamed constructor declarations first, before named ones.
BAD:
dart
class _PriorityItem {
  factory _PriorityItem.forName(bool isStatic, String name, _MemberKind kind) => ...
  _PriorityItem(this.isStatic, this.kind, this.isPrivate);
  ...
}GOOD:
dart
abstract class CancelableFuture<T> implements Future<T>  {
  factory CancelableFuture(computation()) => ...
  factory CancelableFuture.delayed(Duration duration, [computation()]) => ...
  ...
}
Enable
#To enable the sort_unnamed_constructors_first rule,
add sort_unnamed_constructors_first under linter > rules in your
analysis_options.yaml file:
analysis_options.yaml
yaml
linter:
  rules:
    - sort_unnamed_constructors_firstIf you're instead using the YAML map syntax to configure linter rules,
add sort_unnamed_constructors_first: true under linter > rules:
analysis_options.yaml
yaml
linter:
  rules:
    sort_unnamed_constructors_first: true