always_require_non_null_named_parameters

Specify @required on named parameters without defaults.

NOTE: This rule is removed in Dart 3.3.0; it is no longer functional.

DO specify @required on named parameters without a default value on which an assert(param != null) is done.

BAD:

m1({a}) {
  assert(a != null);
}

GOOD:

m1({@required a}) {
  assert(a != null);
}

m2({a: 1}) {
  assert(a != null);
}

NOTE: Only asserts at the start of the bodies will be taken into account.

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

linter:
  rules:
    - always_require_non_null_named_parameters

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

linter:
  rules:
    always_require_non_null_named_parameters: true

Unless stated otherwise, the documentation on this site reflects Dart 3.6.0. Page last updated on 2025-01-27. View source or report an issue.