@ecosy/store

Lightweight state management with slices, reducers, and event-driven architecture for TypeScript applications.

Installation

npm install @ecosy/store
# or
yarn add @ecosy/store

Note: @ecosy/core is installed automatically as a dependency.

API

createSlice

Creates a state slice with auto-generated action creators, a reducer, and event channels.

import { createSlice, type PayloadAction } from "@ecosy/store";

const counterSlice = createSlice({
  name: "counter",
  initialState: { count: 0 },
  reducers: {
    increment: (state) => ({ ...state, count: state.count + 1 }),
    decrement: (state) => ({ ...state, count: state.count - 1 }),
    add: (state, action: PayloadAction<number>) => ({
      ...state,
      count: state.count + action.payload,
    }),
  },
});

// Auto-generated action creators
counterSlice.actions.increment();
// => { type: "$counter:increment" }

counterSlice.actions.add(5);
// => { type: "$counter:add", payload: 5 }

// Reducer
const next = counterSlice.reducer({ count: 0 }, counterSlice.actions.add(5));
// => { count: 5 }

// Event channels
counterSlice.events;
// => { counter: { increment: "$counter:increment", decrement: "$counter:decrement", add: "$counter:add" } }

createStore

Creates a store backed by a Subscriber instance with event wiring and typed actions.

import { createStore } from "@ecosy/store";

const { store, actions } = createStore({
  name: "app",
  initialState: { theme: "light" },
  reducers: {
    toggleTheme: (state) => ({
      ...state,
      theme: state.theme === "light" ? "dark" : "light",
    }),
  },
});

// Listen to state changes
store.onStateChange((state) => {
  console.log("Theme:", state.theme);
});

// Dispatch actions
actions.toggleTheme(); // logs "Theme: dark"

// Get current state
store.getState(); // { theme: "dark" }

Signals

Fire-and-forget events that don't modify state:

const { store, actions } = createStore({
  initialState: { count: 0 },
  reducers: {
    increment: (state) => ({ ...state, count: state.count + 1 }),
  },
  signals: ["reset", "sync"],
});

// Signals are available as actions
actions.signals.reset();
actions.signals.sync();

Types

| Type | Description | |--|--| | PayloadAction<P, T, M, D> | Action with optional payload, meta, and delta | | AnyAction | PayloadAction<any, any, any, any> | | Reducers<State, Action> | Map of reducer handlers | | Slice<State, R, N> | Return type of createSlice | | CreateStoreOptions | Options for createStore | | CreateStoreReturn | Return type of createStore |

getType(prefix, key)

Generates event channel strings:

import { getType } from "@ecosy/store";

getType("counter", "increment"); // "$counter:increment"

Related packages

| Package | Description | |--|--| | @ecosy/core | Types, utilities, and pub/sub subscriber | | @ecosy/react | React hooks for @ecosy/store |

License

MIT