Equatable

Equatable is a Dart library that provides a simple mechanism for value-based equality. It helps developers avoid boilerplate by letting a class define which of its fields should participate in equality comparisons, rather than relying on default identity semantics.

Typically, a class uses Equatable by extending the Equatable base class and overriding a single getter called props to list the fields that should be considered for equality. With this setup, the library implements operator == and hashCode in terms of the values returned by props. As a result, two instances with identical content are considered equal, even if they are distinct objects.

This approach is widely used in Flutter applications, especially with immutable state objects in patterns like Bloc or Cubit, where predictable and efficient equality checks are important for state management and UI updates.

Limitations and considerations include the fact that equality is only as strong as the fields included in props. If nested objects do not implement meaningful equality, you may obtain surprising results unless their own equality is well-defined. Equatable does not provide automatic serialization or deep structural comparisons beyond what is expressed in props. For complex data models, developers often pair Equatable with code-generation tools or other libraries, such as Freezed or built_value, to obtain richer immutability and boilerplate reduction.

In summary, Equatable offers a lightweight, explicit approach to value equality in Dart, balancing simplicity with the needs of common Flutter state-management patterns.