switch_on_type

Avoid switch statements on a 'Type'.

AVOID using switch on Type.

Switching on Type is not type-safe and can lead to bugs if the class hierarchy changes. Prefer to use pattern matching on the variable instead.

BAD:

void f(Object o) {
  switch (o.runtimeType) {
    case int:
      print('int');
    case String:
      print('String');
  }
}

GOOD:

void f(Object o) {
  switch(o) {
    case int():
      print('int');
    case String _:
      print('String');
    default:
      print('other');
  }
}

To enable the switch_on_type rule, add switch_on_type under linter > rules in your analysis_options.yaml file:

linter:
  rules:
    - switch_on_type

If you're instead using the YAML map syntax to configure linter rules, add switch_on_type: true under linter > rules:

linter:
  rules:
    switch_on_type: true

Unless stated otherwise, the documentation on this site reflects Dart 3.8.0. Page last updated on 2025-03-07. View source or report an issue.