prefer-correct-mutated

v1.39.0

warning

effort: 2m

configurable

has IDE fix

has auto-fix

pro+

Warns when a parameter of the collection type (e.g. List or Set) is missing or has an unnecessary @mutated annotation.

@mutated is used to indicated parameters that are being mutated within the function/method body (e.g. .add(element)).

info

To use the @mutated annotation, install the dart-code-metrics-annotations package.

This annotation is used by avoid-mutating-parameters, avoid-collection-mutating-methods and avoid-not-assignable-collection-types rules.

⚙️ Config

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

analysis_options.yaml

dcm:
  rules:
    - prefer-correct-mutated:
        additional-methods:
          - customAddMethod

Example

❌ Bad:

// LINT: This parameter is mutated, but is not annotated with @mutated.
//  Try adding the annotation.
void _extractConditionTargetsMap(Map<String?, String?> targets) {
  targets['23'] = null;
}

// LINT: This parameter is mutated, but is not annotated with @mutated.
//  Try adding the annotation.
void _extractConditionTargets(Set<String?> targets) {
  targets.add(null);
}

// LINT: This parameter is annotated with @mutated, but is not mutated or passed to a @mutated argument.
//  Try removing the annotation.
void _withAnnotation(@mutated Set<String?> targets) {
  print(targets);
}

✅ Good:

void _extractConditionTargetsMap(@mutated Map<String?, String?> targets) {
  targets['23'] = null;
}

void _extractConditionTargets(@mutated Set<String?> targets) {
  targets.add(null);
}

void _withAnnotation(Set<String?> targets) {
  print(targets);
}

Related Rules

• avoid-mutating-parameters
• avoid-collection-mutating-methods
• avoid-not-assignable-collection-types