prefer_class_destructuring

v0.4.0WarningFixConfigurableCollection & Type

This rule is in the pedantic preset.

When you access three or more properties on the same object within a scope, Dart 3 class destructuring can consolidate those accesses into a single declaration. This makes the code more concise and groups related property extractions together.

Why use this rule

Repeated object.property accesses are verbose and scatter related logic across multiple lines. A single destructuring declaration like final MyClass(:name, :email, :age) = object; extracts all needed values at once, making it clear which properties are used in the current scope.

See also: Dart patterns | Destructuring

Don’t

class UserProfile {
  final String name;
  final String email;
  final int age;
  final String address;

  const UserProfile({
    required this.name,
    required this.email,
    required this.age,
    required this.address,
  });
}

// Accessing 3+ properties separately on the same variable
void displayUser(UserProfile user) {
  final greeting = 'Hello, ${user.name}';
  final contact = user.email;
  print('Age: ${user.age}');
}

Do

// Using class destructuring
void displayUser(UserProfile user) {
  final UserProfile(:name, :email, :age) = user;
  final greeting = 'Hello, $name';
  final contact = email;
  print('Age: $age');
}

// Only 2 property accesses (below threshold) — no warning
void showBasicInfo(UserProfile user) {
  print(user.name);
  print(user.email);
}

// Method calls are not counted as property accesses
void interactWithUser(UserProfile user) {
  print(user.name);
  print(user.email);
  user.toString();
}

Turning this rule off

This rule appears only in the pedantic preset because destructuring can obscure the relationship between a value and its properties.

many_lints.yaml

rules:
  prefer_class_destructuring: true

To turn it off again:

many_lints.yaml

rules:
  prefer_class_destructuring: false

To keep the rule on but skip certain paths, use per-rule exclude.

Options

analysis_options.yaml

analysis_options.yaml

many_lints:
  rules:
    prefer_class_destructuring:
      min_occurrences: 4
      ignored_types: [BuildContext, ThemeData]

many_lints.yaml

many_lints.yaml

rules:
  prefer_class_destructuring:
    min_occurrences: 4
    ignored_types: [BuildContext, ThemeData]

Option	Type	Default	Description
min_occurrences	int	3	Minimum number of distinct property accesses on the same variable before the rule reports
ignored_types	list of strings	[]	Type names never reported, for types where destructuring reads worse than repeated access

Related rules

• avoid_accessing_collections_by_constant_index — Avoid accessing a collection by a constant index inside a loop.
• avoid_collection_equality_checks — Avoid comparing collections with == or != as it checks reference equality, not contents.
• avoid_collection_methods_with_unrelated_types — Avoid calling collection methods with arguments whose types are unrelated to the collection’s type parameter.
• avoid_duplicate_collection_elements — Don’t repeat the same element in a collection literal.