fix: add @immutable to EquatableMixin

[felangel]

Status

READY

Breaking Changes

NO

Description

• fix: add @immutable to EquatableMixin

[bambinoua]

Why this? I have many entity classes which are mutable but use the equatable mixin for comparison. Now I need to fix more than 170 warnings (add ignore: must_be_immutable) or switch to the old version because of this change... :\

Could you please to explain how is the equatability related with immutability?

[felangel]

Why this? I have many entity classes which are mutable but use the equatable mixin for comparison. Now I need to fix more than 170 warnings (add ignore: must_be_immutable) or switch to the old version because of this change... :\

Could you please to explain how is the equatability related with immutability?

This is described in the README:

Note: Equatable is designed to only work with immutable objects so all member variables must be final (This is not just a feature of Equatable - overriding a hashCode with a mutable value can break hash-based collections).

[bambinoua]

Then the question is how to compare two entities which properties are mutable? Let's say I have to Customer objects and I need to do something only if changes are detected:

final customerBeforeChange = Customer(...);
final customerAfterChange = customerBeforeChange.copyWith(...);
if (customerBeforeChange != customerAfterChange) {
  // do save
}

Sure, I can compare them property-by-property, but if the classes have too many properties, enumerating them will take time. The single initialization of props in Equatable was saving me.

[BirjuVachhani]

This has so much impact on our codebase that we decided to lock down on version 2.0.5 just to have piece of mind.