Arrow (=>) handling inconsistency between getter and switch expression (introduced in 3.9)

[chris-NR]

Formatted with ^3.6.0 specified in pubspec.yaml

class Report {
  final Event event;
  final List<Item> _items;
  Report(this.event, this._items);
  Iterable<Item> get all => _items;
  List<Relation> relations() => [Relation(_items[0], _items[1])]; // stub

  List<ItemDetail> get itemDetails => switch (event) {
        EventPartial _ => all
            .map(
              (item) => ItemDetail(
                item,
                relations()
                    .map(
                      (relation) => RelationDetail(
                        relation,
                        Details.getRelationText(relation),
                      ),
                    )
                    .toList(),
              ),
            )
            .toList(),
        _ => throw UnimplementedError(),
      };

  List<RelationDetail> get relationDetails => all
      .expand((item) => relations())
      .map(
        (relation) =>
            RelationDetail(relation, Details.getRelationText(relation)),
      )
      .toList();
}

Formatted with ^3.7.0 specified in pubspec.yaml

class Report {
  final Event event;
  final List<Item> _items;
  Report(this.event, this._items);
  Iterable<Item> get all => _items;
  List<Relation> relations() => [Relation(_items[0], _items[1])]; // stub

  List<ItemDetail> get itemDetails => switch (event) {
    EventPartial _ =>
      all
          .map(
            (item) => ItemDetail(
              item,
              relations()
                  .map(
                    (relation) => RelationDetail(
                      relation,
                      Details.getRelationText(relation),
                    ),
                  )
                  .toList(),
            ),
          )
          .toList(),
    _ => throw UnimplementedError(),
  };

  List<RelationDetail> get relationDetails =>
      all
          .expand((item) => relations())
          .map(
            (relation) =>
                RelationDetail(relation, Details.getRelationText(relation)),
          )
          .toList();
}

Formatted with ^3.9.0 specified in pubspec.yaml

class Report {
  final Event event;
  final List<Item> _items;
  Report(this.event, this._items);
  Iterable<Item> get all => _items;
  List<Relation> relations() => [Relation(_items[0], _items[1])]; // stub

  List<ItemDetail> get itemDetails => switch (event) {
    EventPartial _ =>
      all
          .map(
            (item) => ItemDetail(
              item,
              relations()
                  .map(
                    (relation) => RelationDetail(
                      relation,
                      Details.getRelationText(relation),
                    ),
                  )
                  .toList(),
            ),
          )
          .toList(),
    _ => throw UnimplementedError(),
  };

  List<RelationDetail> get relationDetails => all
      .expand((item) => relations())
      .map(
        (relation) =>
            RelationDetail(relation, Details.getRelationText(relation)),
      )
      .toList();
}

What output did you expect or want the formatter to produce?

The issue for me is the handling of the => in the switch expression. I prefer the output of v3.6.0 as the additional line break between the arrow "=>" and "all" is both jarring and creates an unnecessary extra level of indentation making it harder to read.