Store Directory Data for Mocking

First level directory to JSON.quokka.es6

// For Node.js

import fs from 'fs';
import path from 'path';
import vm from 'vm';

const vm_eval = (x)=>{
    return vm.runInNewContext(x);
};
const lambda = 'λ';
const basePath = '/home/grmartin';
const rooter = (next) => path.join(basePath, next);
const defn = (obj) => {
    const out = obj;
    const fn = function (x) { return `${lambda}/${x}`; };
    obj.isBlockDevice = fn(obj.isBlockDevice());
    obj.isCharacterDevice = fn(obj.isCharacterDevice());
    obj.isDirectory = fn(obj.isDirectory());
    obj.isFIFO = fn(obj.isFIFO());
    obj.isFile = fn(obj.isFile());
    obj.isSocket = fn(obj.isSocket());
    obj.isSymbolicLink = fn(obj.isSymbolicLink());
    return out;
};
const buildEntry = (filePath) => ({
    path: filePath,
    stat: defn(fs.statSync(filePath))
});
const pretty= (x) => JSON.stringify(x, null, ' ');

const parser = (x) => JSON.parse(x, (() => {
    const dt = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*))(?:Z|([+\-])([\d|:]*))?$/;
    const fn = RegExp(`^${lambda}\/(.*?)$`);

    const xforms = [
        (_, v) => (typeof v === 'string' && dt.test(v)) ? new Date(v) : v,
        (_, v) => (typeof v === 'string' && fn.test(v)) ? vm_eval(`()=>(${fn.exec(v)[1]})`) : v,
    ];

    return (key, value) => {
        for (let i = 0; i < xforms.length; i++) {
            let out = xforms[i](key, value);
            if (out !== value) {
                return out;
            }
        }
        return value;
    }
})());

const json = pretty(fs.readdirSync(basePath)
    .map(rooter)
    .map(buildEntry)) /*?*/

const out = parser(json) /*?*/

out[0].stat.isDirectory() /*?*/
out[0].stat.isFile() /*?*/