TypeScript Redux Sample Action & Reducer | https://github.com/codeBelt/typescript-hapi-react-hot-loader-example

IAction.ts

/**
 * https://github.com/acdlite/flux-standard-action
 */
export interface IAction<T> {
    type: string;
    payload?: T;
    error?: boolean;
    meta?: any;
}

ISampleReducerState.ts

export interface ISampleReducerState {
    readonly isLoading: boolean;
}

SampleAction.ts

import {IAction} from '../IAction';

export class SampleAction {

    public static readonly SET_LOADING: string = 'SampleAction.SET_LOADING';

    public static setLoading(isLoading: boolean): IAction<boolean> {
        return {
            type: SampleAction.SET_LOADING,
            payload: isLoading,
        };
    }

}

SampleReducer.ts

import {IAction} from '../IAction';
import {ISampleReducerState} from './ISampleReducerState';
import {SampleAction} from './SampleAction';

export class SampleReducer {

    private static readonly _initialState: ISampleReducerState = {
        isLoading: false,
    };

    public static reducer(state: ISampleReducerState = SampleReducer._initialState, action: IAction<any>): ISampleReducerState {
        switch (action.type) {
            case SampleAction.SET_LOADING:
                return SampleReducer._setLoading(state, action);
            default:
                return state;
        }
    }

    private static _setLoading(state: ISampleReducerState, action: IAction<boolean>): ISampleReducerState {
        return {
            ...state,
            isLoading: action.payload,
        };
    }

}