Node Auto Loader (NAL)

Node Auto Loader (NAL) is a dependency free single file module auto loader. NAL is capable of automatically auto loading CommonJS (CJS) modules, ES6 (MJS) modules, and JSON files. You should consider using NAL if:

:heavy_check_mark:  You have a lot of modules to require/import at once.

:heavy_check_mark:  You want to modularize your application.

:heavy_check_mark:  You want to automate a process; auto loading many Express routes or MongoDB schemas for example.

Installation

Automatic

NAL can be installed with npm and will run in either CommonJS (CJS) or ES6 (MJS) projects. Add NAL as a dependency for your project with:

npm install node-auto-loader

Manual

NAL can be manually incorporated into your CommonJS projects by adding the auto-loader.js file into your project, and then requiring it where needed:

const AutoLoader = require('./auto-loader');

If you manually alter the auto-loader.js file and convert it into an ES6 (MJS) module, you can import it in ES6 projects:

import AutoLoader from './auto-loader.js';

NOTE: Manual installs are not recommended, use the automatic install instead to automatically receive updates.

Usage

NAL can be instantiated and run with various options. Here is a simple example of NAL being used to auto load modules from a fictional modules directory:

// CommonJS require:
const AutoLoader = require('node-auto-loader');
// OR ES6 import:
import AutoLoader from ('node-auto-loader');

// Get a new instance of AutoLoader and set it to load the modules directory.
const autoLoader = new AutoLoader('./modules');

/*
 * Modules are automatically loaded then passed to a callback function. You can
 * do whatever you need to in the callback function, like invoking a module, or
 * nothing if you just needed the module to be loaded; this is always required!
 */
function callback(module) { ... }

/*
 * Optional callback function that must return a true or false. This allows you
 * to decide if a module should be auto loaded (true) or skipped (false).
 */
function checkModuleFirst(pathToModule) { ... }

// What options to use when loading modules. If missing defaults will be used.
const options = {
    allowJSON: false,
    checkFirst: checkModuleFirst,
    recursive: true
}

/**
 * Load the modules automatically. You do not need to capture the results
 * unless you want to. The results object will let you know what was
 * successfully auto loaded and what errors may have occurred.
 */
let results = await autoLoader.loadModules(callback, options);

:bookmark: NAL Methods

getAllowed

• Returns an array of the autoLoader's allowed file types; usually ['.js', '.cjs', '.mjs'] if JSON was not allowed.

getDirectory

• Returns the absolute path to the directory autoLoader is currently configured to load; defaults to __dirname.

getType

• Returns the type of module autoLoader will attempt to load modules as; CommonJS (CJS) or ES6 (MJS) module.

loadModules(callback[, options])

• Returns a new Promise that will attempt to auto load all modules set by setDirectory or the directory autoLoader was instantiated with.
• callback is required. If you only need modules to auto load and do not need to invoke anything else, callback can be an empty function.
• options is an object that allows you to alter the way loadModules works; see next section for more information.

setType(type)

• type can be either CJS for CommonJS modules or MJS for ES6 modules.
• AutoLoader will detect the correct type for your project automatically, but you can use this to forcefully set the type.

setDirectory(pathToDir)

• pathToDir is a relative or absolute path to the directory to auto load.
• Allows changing the directory autoLoader uses after instantiation.

:bookmark: NAL loadModules Options

The loadModules method accepts an optional options object. You can uses this object to alter the way loadModules works:

allowJSON    default: false

• Set to true if you would like autoLoader to also auto load JSON files for you.
• JSON files are loaded with the node fs package, not required or import; this means they will not be cached.

checkFirst    default: null

• Set to a function that will be called before autoLoader attempts to load a module.
• Will receive a single argument filePath allowing you to determine if the module should be loaded (true) or not (false); must return a true or false value!

recursive    default: true

• Set to false if you do not want the autoLoader to recursively load modules.
• When false this will stop loadModules from recursively searching all directories under the configured directory for modules.

Changelog

The current changelog is here. All other changelogs are here.

Contributions

NAL is an open source community supported project, if you would like to help please consider tackling an issue or making a donation to keep the project alive.

Reminder: Before submitting new pull requests make sure to run npm test. If you add a new feature make sure it is covered by a new or existing test.