asyncredux-state-design

To design immutable AppState for AsyncRedux, use final fields, a static initialState() factory for defaults, and a copy() method to generate new instances without mutating the original state.

The copy() pattern for nested state objects in Flutter creates new parent and child instances during modifications, ensuring nested composition like User or TodoList inside AppState remains immutable.

The best way to manage collections in immutable Flutter AppState is using fast_immutable_collections, integrating IList, ISet, and IMap to efficiently handle collection updates without mutating existing state.

You do not need fast_immutable_collections to use AsyncRedux state design, as integration with IList, ISet, and IMap is optional, allowing final fields and copy() methods to manage state independently.

Use a static initialState() factory instead of a default constructor for AppState to provide standardized default values, ensuring the AsyncRedux store initializes with a clean, immutable state instance.