28줄의 코드로 redux 만들기

function createStore(reducer, initialState) {
    let state = initialState;

    function getState() {
        return state;
    }

    function dispatch(action) {
        state = reducer(state, action);
    }

    return { dispatch, getState };
}

function reducer(state = [], action) {
    switch (action.type) {
        case "add":
            return [...state, action.payload];
        default:
            return state;
    }
}

const store = createStore(reducer);
store.dispatch({ type: "add", payload: "learn to code" });
store.dispatch({ type: "add", payload: "react" });
store.getState();
//[ 'learn to code', 'react' ]