list_all_equatable_fields

v0.4.0 Warning Fix Collection & Type

Classes that extend Equatable or use EquatableMixin must include all declared instance fields in the props getter. Missing fields means two instances with different values for those fields will be considered equal, leading to hard-to-find bugs.

Why use this rule

Forgetting to add a field to props silently breaks equality comparisons. Two objects that differ only in the missing field will appear equal, which can cause incorrect behavior in collections, state management, and testing.

See also: equatable package

Don’t

import 'package:equatable/equatable.dart';

// Missing 'age' from props
class BadPerson extends Equatable {
  const BadPerson(this.name, this.age);
  final String name;
  final int age;

  @override
  List<Object?> get props => [name];
}

// Missing all fields from props
class BadEmpty extends Equatable {
  const BadEmpty(this.x, this.y);
  final double x;
  final double y;

  @override
  List<Object?> get props => [];
}

// Using EquatableMixin with missing field
class BadMixinPerson with EquatableMixin {
  BadMixinPerson(this.name, this.email);
  final String name;
  final String email;

  @override
  List<Object?> get props => [name];
}

Do

import 'package:equatable/equatable.dart';

// All fields are listed in props
class GoodPerson extends Equatable {
  const GoodPerson(this.name, this.age);
  final String name;
  final int age;

  @override
  List<Object?> get props => [name, age];
}

// All fields listed with EquatableMixin
class GoodMixinPerson with EquatableMixin {
  GoodMixinPerson(this.name, this.email);
  final String name;
  final String email;

  @override
  List<Object?> get props => [name, email];
}

// Static fields are correctly excluded
class PersonWithStatic extends Equatable {
  const PersonWithStatic(this.name);
  final String name;
  static const maxNameLength = 100;

  @override
  List<Object?> get props => [name];
}

// No fields means empty props is fine
class EmptyEquatable extends Equatable {
  const EmptyEquatable();

  @override
  List<Object?> get props => [];
}

Configuration

To disable this rule:

plugins:
  many_lints:
    diagnostics:
      list_all_equatable_fields: false