avoid-unnecessary-type-assertions

added in: 1.6.0

warning

Pro+

preset: recommended

Warns about unnecessary usage of the is operator, and whereType and whereNotNull methods.

Example

Example 1: check is same type

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

  void main() {
    final result = myList is List<int>; // LINT
    myList.whereType<int>();
  }
}

Example 2: whereType method

main(){
  ['1', '2'].whereType<String?>(); // LINT
}

Example 3: patterns

class Animal {}

class HomeAnimal extends Animal {}

void main() {
  final animal = Animal();

  if (animal case HomeAnimal result) {}
  if (animal case HomeAnimal()) {}

  if (animal case Animal result) {} // LINT
  if (animal case Animal()) {} // LINT
}