How to make a generic Node JS module?

Question

JavaScript

There is a database module

function createBD(){
    console.log('create BD');
};

exports.createBD = createBD;

The application is launched like this: node project.js
And declared in project.js: var bd = new bd.createBD();
Other modules are also connected in project.js, the question is how to use one created object (one module) in all connected modules, that is, not to create a new database object in each module (var bd = new bd.createBD() ;), but connect it once and use it in the connected modules of one project?

Answer 1

function createBD(){
console. log('create BD');
};
module.exports = new createDB();

Answer 2

var bd = new bd.createBD();
//update: SomeModule - загруженный через require модуль
var mModule = new SomeModule(bd);

--- any module that uses the bd object is styled like this ----
------- SomeModule ---------

var lDb = undefined;

module.exports = function(dbObject)
{
    // как-то проверяем значение dbObject. Если не допустимое значение - ошибка
    lDb = dbObject;// внутренний объект bd
    // тут объекты, методы текущего модуля
   ...
}

You can try like this.

Answer 3

Use the Global, Luke!

// In application entry point or framework
global.api = {};
api.fs = require('fs');
api.http = require('http');
require('./db');
require('./application');
global.db = new api.db.createDatabase();

// In DB module: db.js
api.db = {};
api.db.createDatabase = function() {
  console.log('Create DB');
};

// In any place and any applied module
db.select('.....or whatever you want');

It is also good to master sandboxes for escaping modules and application code in different globals: https://github.com/HowProgrammingWorks/InversionOf...