Fs-handy-wraps NPM

Handy Wraps for Node.js FS

A pretty simple library. It uses fs-extra under the hood.

Installation

npm i -S fs-handy-wraps or yarn add fs-handy-wraps

Constants

HOME is a path to the Home directory of the current OS user.

CWD is a path to the Current Working Directory.

fse is an object that exposes fs-extra functions as is.

Functions for Reading and Writing files

All the functions are promisified. Only first argument is required.

check (path, existCallback, absentCallback)

Checks the file existence. All arguments are required.

read (path, successCallback, errCallback)

Reads the file contents.

write (path, text, successCallback, errCallback)

Rewrites the file content by text or an empty string. Also may be used for a new file creation. If the target folder does not exist, it will be created.

rm (path)

Removes specified file of folder as it rm -rf does. Resolves to a true value if succeeded.

append (path, text, successCallback, errCallback)

Appends text or an empty string to the end of the file.

rom (path, make, readCallback)

Reads the file if it exists and calls readCallback then. Creates a new file if it does not exist. If argument make is not specified new file will be empty. If typeof make === string it will be the content of the new file. If typeof make === function it will be a callback with arguments: (resolve, reject). This callback should call resolve with a content for the new file. See examples below.

dir (path, successCallback, errCallback)

Creates a directory specified by path. This function is imported from fs-extra. Here is its documentation.

Read or Create a JSON config-file using simple CLI

getConfig (path, defProvider, CLIQuestions, successCallback, errCallback)

Reads the path file, checks if for JSON errors and calls successCallback (parsedConfig). If the file does not exist -- creates it according to default content provided by defProvider. defProvider may be: an object or a function that returns an object or a promise. If CLIQuestions specified, a simple CLI will be started. Example for CLIQuestions object:

const CLIQuestions_EXAMPLE = [
    { prop: 'pathToBase',     question: 'Full path to database file:' },
    { prop: 'pathToNotefile', question: 'Path to temp file:' },
    { prop: 'editor',         question: 'Command to open your text editor:' },
];

It asks CLIQuestions to user, then assigns received values to a default object. A callback successCallback (config) will be executed in the result.

Watching on file changes

Only for for testing purposes. In production, use chokidar instead.

This function cannot be promisified.

watch (path, callback)

Creates a Watcher that will call the callback every time a file specified by path is changed. There are a 30ms delay between the system event and the callback is called.

Usage example (with callbacks)

const FILE = require('fs-handy-wraps');
const configPath = '~/config.json';
const configDefaults = {
    base: '~/base.txt',
    name: 'My new Project'
};
const cli = [
    { prop: 'base', question: 'Where to store the database?' },
    { prop: 'name', question: 'What is the name of your Project?' },
];

start();

function start() {
    FILE.getConfig (configPath, configDefaults, cli, checkBase);
}
function checkBase (config) {
    FILE.rom (config.base, createNewBase, parseBase);
}
function parseBase (baseContent) {
    // do something with baseContent...
}
function createNewBase (resolve, reject) {
    // do something to get the new base content...
    resolve(content);
}

Usage with promises (async / await syntax)

const FILE = require('fs-handy-wraps');

const pathDefaultFile = 'fileDef.txt';
const pathFile = 'file.txt';

// if pathFile is already exists --> read it
// else --> create a new file based on the another one.
(async function start() {
    const content = await FILE.rom(pathFile, makeDefault);
    console.log(content);

    async function makeDefault(resolve, reject) {
        resolve(await FILE.read(pathDefaultFile));
    }
})()