mutable helpers

import {useState, useReducer} from 'react';
// also add immer

const DEFAULT = 'DEFAULT';
export const ADD_MARKER_FEATURE = 'ADD_MARKER_FEATURE';
export const CREATE_FEATURES_LAYER = 'CREATE_FEATURES_LAYER';

export function useMutation(initialValue) {
    const [val, updateValue] = useState(initialValue);
    return [
        val,
        (updater) => {
            updateValue(updater);
        }
    ];
}

export function useMutableReducer(reducer, initialState) {
    return useReducer(reducer, initialState);
}

export function mutableReducer(draft, action) {
    const reducer = {
        ADD_MARKER_FEATURE: () => draft.push(action.markerFeature),
        DEFAULT: () => null
    };
    return (reducer[action.type] || reducer[DEFAULT])();
}