avoid-collection-mutating-methods

added in: 1.11.0

warning

⚙️

Warns when a mutating method is called on a collection.

By default this rule triggers on every method that has a void return type, as well as for methods in the methods config option.

⚙️ Config

Set ignore-local (default is true) to exclude local variables.

Set methods (default is [remove, removeAt, removeLast, putIfAbsent, update]) to override the list of methods to check.

Set additional-methods (default is empty) to add additional methods the list of methods to check.

dart_code_metrics:
  ...
  rules:
    ...
    - avoid-collection-mutating-methods:
        ignore-local: true
        additional-methods:
          - contains

Example

❌ Bad:

void main {
  final list = [1, 2, 3];

  list.remove(1); // LINT
  list.insert(0, 4); // LINT
  list.addAll([1, 2, 3]); // LINT
  list.removeAt(0); // LINT
  list.shuffle(); // LINT

  final primitiveMap = Map<int, String>();
  check(primitiveMap.addAll); // LINT
}

void check(void Function(Map<int, String>) callback) {}

✅ Good:

void main {
  final list = [1, 2, 3];

  final newList = [...list, ...[1, 2, 3]];
}