Make usePortal initial state either a state or function of the state.

src/addons/withImplementation.ts

@@ -88,7 +88,7 @@ export function usePortalImplementation<
 
   /**
    * Return an array containing the current state and the setter function for state updates.
-   * @type {PortalState<S, A>}
+   * @type {PortalState<State>}
    */
   return [select(observable.value), observable.setter];
 }

src/component/usePortal.ts

@@ -7,7 +7,7 @@ import {
   UsePortal,
 } from "@/definition";
 import { usePortalImplementation } from "@/addons";
-import { getValue } from "@/utilities";
+import { getResolvedState, getValue } from "@/utilities";
 import { cookieStorage } from "./cookieStorage";
 
 /**
@@ -29,7 +29,7 @@ export function usePortal<
 >(path: Path, options?: PortalOptions<Store, State, Data>) {
   const initialState = options?.store
     ? getValue(options.store, path)
-    : options?.state;
+    : getResolvedState(options?.state);
 
   return usePortalImplementation<Store, Path, State, Data>({
     path,
@@ -63,7 +63,7 @@ function useLocal<
 
   const initialState = config?.store
     ? getValue(config.store, path)
-    : config?.state;
+    : getResolvedState(config?.state);
 
   return usePortalImplementation<Store, Path, State, Data>({
     path,
@@ -97,7 +97,7 @@ function useSession<
 
   const initialState = config?.store
     ? getValue(config.store, path)
-    : config?.state;
+    : getResolvedState(config?.state);
 
   return usePortalImplementation<Store, Path, State, Data>({
     path,
@@ -132,7 +132,7 @@ function useCookie<
 
   const initialState = config?.store
     ? getValue(config.store, path)
-    : config?.state;
+    : getResolvedState(config?.state);
 
   return usePortalImplementation<Store, Path, State, Data>({
     path,

src/definition/cookie.ts

@@ -47,8 +47,7 @@ export type CookieOptions = {
 };
 
 /**
- * Represents a cookie entry with additional properties for storing state data.
- * @template S The type of the state value to be stored in the cookie entry.
+ * Represents a cookie entry in the cookie storage.
  */
 export type CookieEntry = CookieOptions & {
   /**
@@ -103,4 +102,4 @@ export interface CookieStorage extends Storage {
    * @returns {string | null} The cookie value if found, or null if not found.
    */
   key: (index: number) => string | null;
-}
+}

src/definition/portal.ts

@@ -16,9 +16,11 @@ export type PortalOptions<Store, State, Data = State> = {
    * The initial value of the portal.
    *
    * @description
-   * If the `path` is defined within the portal, the state will be ignored.
+   * - This value is only used when the `path` is not defined within the portal.
+   * - This value will be overidden if the `get` method is defined.
+   * - It uses the `useState` hook internally.
    */
-  state?: State;
+  state?: State | (() => State);
 
   /**
    * Select the required data from the state.
@@ -43,9 +45,8 @@ export type PortalOptions<Store, State, Data = State> = {
    * Method to get the initial value.
    *
    * @description
-   * - When the `get` method is undefined, the initial value will be used.
-   * - If `override` is false, the value returned will not override the initial value.
-   * - This method is only called once, except when the `key` changes.
+   * - This method is only called when the `path` is not defined within the portal.
+   * - It uses the `useEffect` hook internally.
    */
   get?: GetState<State>;
 };
@@ -98,6 +99,14 @@ export type PortalValue<State> = {
   observable: BehaviorSubject<State>;
 };
 
+/**
+ * Represents the options for the usePortal hook.
+ * 
+ * @template State The type of the state.
+ * @template Path The type of the path.
+ * @template Store The type of the store.
+ * @template Data The type of the data.
+ */
 export interface UsePortalImplementation<
   Store extends Record<string, any>,
   Path extends Paths<Store>,
@@ -111,14 +120,14 @@ export interface UsePortalImplementation<
 
 /**
  * Represents a map of keys and values in the portal entries.
- * @template S The type of the store value.
- * @template A The type of the action for the reducer.
+ * @template State The type of the state.
+ * @template Path The type of the path.
  */
 export type PortalMap<State, Path> = Map<Path, PortalValue<State>>;
 
 /**
  * Represents the result of the usePortal hook.
- * @template State The type of the store value.
+ * @template State The type of the state.
  */
 export type PortalState<State, Data = State> = [
   Data,

src/subject/behaviorSubject.ts

@@ -3,15 +3,15 @@ import { isSetStateFunction } from "@/utilities";
 
 import type { Subscription } from "@/definition";
 
-abstract class Subject<S> {
-  abstract next(value: S): void;
-  abstract subscribe(observer: (value: S) => void): Subscription;
+abstract class Subject<State> {
+  abstract next(value: State): void;
+  abstract subscribe(observer: (value: State) => void): Subscription;
   abstract unsubscribe(): void;
 }
 
 /**
  * Represents a subject that maintains a current value and emits it to subscribers.
- * @template S The type of the initial and emitted values.
+ * @template State The type of the initial and emitted values.
  */
 export class BehaviorSubject<State> implements Subject<State> {
   private state: State;
@@ -51,15 +51,15 @@ export class BehaviorSubject<State> implements Subject<State> {
 
   /**
    * Returns the current value of the subject.
-   * @returns {S} The current value.
+   * @returns {State} The current value.
    */
   get value(): State {
     return this.state;
   }
 
   /**
    * Emits a new value to the subject and notifies subscribers.
-   * @param {S} value The new value to emit.
+   * @param {State} value The new value to emit.
    */
   next = (value: State) => {
     if (!Object.is(this.state, value)) {
@@ -69,17 +69,12 @@ export class BehaviorSubject<State> implements Subject<State> {
   };
 
   /**
-   * Update the state using the provided value or action.
+   * Update the state using the provided value.
+   * @description The updated state is emitted through the `observable.next()` method.
+   * 
    * @template State The type of the state.
    *
-   * @param {SetStateAction<S, A>} value Value or action to update the state with.
-   *
-   * @summary If a dispatch function is provided, it is used to process the state update based on the previous state and the value or action.
-   * @summary If the dispatch function is not provided and the value is a function, it is called with the previous state and the return value is used as the new state.
-   * @summary If neither a dispatch function is provided nor the value is a function, the value itself is used as the new state.
-   *
-   * @description The updated state is emitted through the observable.next() method.
-   *
+   * @param {SetStateAction<State>} value Value to update the state with.
    * @returns void
    */
   setter = (value: SetStateAction<State>) => {

src/subject/portal.ts

@@ -2,8 +2,6 @@ import { handleSSRError } from "@/utilities";
 import { cookieStorage } from "@/component";
 
 import type {
-  CookieEntry,
-  CookieOptions,
   PortalMap,
   PortalValue,
   SetStore,
@@ -35,7 +33,6 @@ class Portal {
    *
    * @param {string} path The path of the item to be retrieved.
    * @param {State} initialState The initial state of the item.
-   * @param {boolean} [override=false] Whether to override an existing item with the same path.
    *
    * @returns {PortalValue<State, Path>} The portal entry with the specified path, or a new portal entry if not found.
    */
@@ -51,6 +48,7 @@ class Portal {
       observable: new BehaviorSubject(initialState),
       storage: new Set<SetStore<State>>(),
     };
+
     this.portalMap.set(path, subject);
     return subject;
   };

src/utilities/getComputedState.ts

@@ -3,14 +3,14 @@ import { isSetStateFunction } from "./isSetStateFunction";
 
 /**
  * Gets the actual state value from the provided initial state.
- * @template S The type of the initial state value.
- * @param {S | ((prevState: S) => S)} initialState The initial state value or a function that returns the initial state.
- * @returns {S} The actual state value.
+ * @template State The type of the initial state value.
+ * @param {State | ((prevState: State) => State)} initialState The initial state value or a function that returns the initial state.
+ * @returns {State} The actual state value.
  */
-export function getComputedState<S>(
-  initialState: SetStateAction<S>,
-  previousState: S
-) {
+export function getComputedState<State>(
+  initialState: SetStateAction<State>,
+  previousState: State
+): State {
   if (isSetStateFunction(initialState)) return initialState(previousState);
   return initialState;
 }

src/utilities/getResolvedState.ts

@@ -0,0 +1,14 @@
+import { isFunction } from "./isFunction";
+
+/**
+ * Gets the actual state value from the provided initial state.
+ * @template State The type of the initial state value.
+ * @param {State | (() => State)} initialState The initial state value or a function that returns the initial state.
+ * @returns {State} The actual state value.
+ */
+export function getResolvedState<State>(
+  initialState: State | (() => State)
+): State {
+  if (isFunction(initialState)) return initialState();
+  return initialState;
+}

src/utilities/index.ts

@@ -1,4 +1,5 @@
 export * from "./getComputedState";
+export * from "./getResolvedState";
 export * from "./handleSSRError";
 export * from "./getValue";
 export * from "./isAtomStateFunction";

src/utilities/isSetStateFunction.ts

@@ -3,8 +3,8 @@ import { SetStateAction } from "react";
 /**
  * Type guard to check if a value is a SetStateAction function.
  *
- * @template S The type of the state.
- * @param {SetStateAction<S>} value The value to be checked.
+ * @template State The type of the state.
+ * @param {SetStateAction<State>} value The value to be checked.
  * @returns {boolean} `true` if the value is a SetStateAction function, otherwise `false`.
  */
 export function isSetStateFunction<State>(

src/utilities/objectToStringKey.ts

@@ -2,7 +2,7 @@ type Primitives = string | number | bigint | boolean | null | undefined;
 type ToString<T> = T extends Primitives ? `${T}` : Extract<T, string>;
 
 type ArrayToString<T extends any[]> = T extends [infer First, ...infer Rest]
-  ? `${ToString<First>}${Rest extends [] ? "" : ","}${ObjectToStringKey<Rest>}`
+  ? `${ToString<First>}${Rest extends [] ? "" : ","}${ArrayToString<Rest>}`
   : "";
 
 type UnionToIntersection<U> = (
@@ -25,8 +25,9 @@ type Construct<K extends keyof T, T> = ObjectToStringKey<T[K]> extends infer U
 
 type Flat<K, T> = UnionToTuple<K> extends [infer First, ...infer Rest]
   ? First extends keyof T
-    ? `${Construct<First, T>}${Rest extends [] ? "" : ";"}${ObjectToString<
-        Pick<T, Exclude<keyof T, First>>
+    ? `${Construct<First, T>}${Rest extends [] ? "" : ";"}${Flat<
+        Exclude<keyof T, First>,
+        T
       >}`
     : never
   : never;
@@ -37,30 +38,21 @@ type ObjectToString<T> = keyof T extends never
   ? Flat<K, T>
   : never;
 
-type ObjectToStringKey<T> = T extends any[]
+type ObjectToStringKey<T> = T extends string
+  ? T
+  : T extends any[]
   ? ArrayToString<T>
   : T extends object
   ? ObjectToString<T>
   : ToString<T>;
 
-type NestedObject<
-  T extends Record<string, any>,
-  P extends string[]
-> = P extends [infer First, ...infer Rest]
-  ? First extends string
-    ? Rest extends string[]
-      ? { [K in First]: NestedObject<T, Rest> }
-      : never
-    : never
-  : T;
-
 /**
  * Converts a reference type to a string representation that can be used as a key.
  *
  * @param {any} value The value to convert.
  * @returns {string} The string representation of the value.
  */
-export function objectToStringKey(value: any): string {
+export function objectToStringKey<T>(value: T): string {
   if (typeof value === "object" && value !== null) {
     if (Array.isArray(value)) {
       const arrayString = value.map(objectToStringKey).join(",");