import type { ActionMessage } from "../actions";
import type { State } from "./State";
/**
 * Check object shape to see if
 * its a valid ILeafReducer
 *
 * @param o
 * @returns {boolean}
 */
export declare function isLeafReducer(o: any): o is ILeafReducer<any, any>;
/**
 * S - type of State
 * T - type of actions/enum
 * M - type of message
 */
export interface ILeafReducer<S extends State, A extends ActionMessage<S> = ActionMessage<S>> {
    /**
     * The path to the leaf it handles
     */
    leaf(): string;
    /**
     * Get the default state
     */
    defaultState(o?: any): S;
    /**
     * Optional init function coverage
     *
     * @param state
     */
    init?: (state: S) => S;
    /**
     * Handle an incoming action
     * @param state
     * @param action
     */
    handle?: (state: S, action: A) => S;
    /**
     * Handle an error occurence
     *
     * @param state
     * @param action
     * @param error
     */
    handleError?: (state: S, action: A, error: Error) => S;
}