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prefer-typedefs-for-callbacks

added in: 1.11.0
style
⚙️
Pro+

Warns when a Function type is declared not as a typedef.

⚙️ Config​

Set ignore-fields (default is false) to exclude fields from the check.

Set ignore-parameters (default is false) to exclude parameters from the check.

Set ignore-type-arguments (default is false) to exclude type arguments from the check.

Set ignore-return-types (default is false) to exclude return types from the check.

dart_code_metrics:
  ...
  rules:
    ...
    - prefer-typedefs-for-callbacks:
        ignore-fields: false
        ignore-parameters: false
        ignore-type-arguments: false
        ignore-return-types: false

Example​

❌ Bad:

class SomeWidget {
  final void Function() onEnterButton; // LINT

  const SomeWidget(
    this.onEnterButton,
  );

  void another({
    void Function()? onRemoved, // LINT
  }) {}
}

✅ Good:

class SomeWidget {
  final VoidCallback onEnterButton;

  const SomeWidget(
    this.onEnterButton,
  );

  void another({
    VoidCallback? onRemoved,
  }) {}
}