avoid-unnecessary-type-casts

v1.6.0

warning

recommended

pro+

Warns about unnecessary use of the as operator and cast method.

Unnecessary type casts are either a sign of a bug (another type should be used instead or the type hierarchy should include the expected type) or are redundant and can simply be removed.

Example

❌ Bad:

class Example {
  final myList = <int>[1, 2, 3];

  void main() {
    // LINT: Avoid unnecessary 'as' type cast.
    final result = myList as List<int>;

    final animal = Animal();
    // LINT: Avoid unnecessary 'as' type cast.
    if (animal case HomeAnimal() as Animal) {}
  }
}

class Animal {}

class HomeAnimal extends Animal {}

✅ Good:

class Example {
  final myList = <int>[1, 2, 3];

  void main() {
    final result = myList;

    final animal = Animal();
    if (animal case HomeAnimal()) {}
  }
}

Additional Resources

• CWE-1164: Irrelevant Code

Related Rules

• avoid-unrelated-type-casts
• avoid-unnecessary-type-assertions