es6-class

I want to merge 2 classes or add all methods from 1 class to another. In the future It will be the more classes than just a (ContainerClient) class. Client and ContainerClient I tried this but I think It can be done even easier. for (var a of Object.getOwnPropertyNames(ContainerClient.prototype)) { Client.prototype[a] = ContainerClient.prototype[a]; } Principle: ContainerClient depends on Client Data.js class Data { constructor () { } } Client.js class Client extends Data { me () { return { id: '1', }; } } Container.js class Container extends Data { containers () { return [ { clientId: '1', id

I am trying to create a simple logger class with Winston . I created two loggers named Logger and Error which extends from Logger . The Logger class by default creates all the logs in al-logs.log and Error class when extending from Logger adds an additional transport to create all error logs inside error-logs.log . But no logs are created inside error-logs.log . What am I missing? Here is what I did: First, I created the Logger class: class Logger { constructor(serviceName, label = "") { this.logger = winston.createLogger({ level: "debug", format: winston.format.combine( winston.format.label({

I am trying to set an eslint rule for methods in class that are never used. Like in the following react component I have a method unUsedMethod which is never used, but eslint does not show an error for it. class Sample extends Component { unUsedMethod() { console.log('I am never used'); } render() { return 'Hello!'; } } My eslint file looks like this { "parser": "babel-eslint", "env": { "browser": true, "es6": true, "node": true }, "extends": ["eslint:recommended", "plugin:react/recommended"], "parserOptions": { "ecmaFeatures": { "experimentalObjectRestSpread": true, "jsx": true, "sourceType":

There are many ways one can declare a function in javascript. One of the ways is declaring a class and a static function inside is as showed below. class className { static fucntionName() { } } another way of is declaring is through the tradition javascript style as showed below. export function functionName() { } I would like to know the advantages/disadvantages of using either of the cases. Is there any specific use cases for the static methods, why declare a class(we know that in javascript there is no need to instantiate the class in order to access the static function). Why not just use

This question already has answers here : How to access the correct `this` inside a callback? (10 answers) Closed 3 years ago . I am making an app using Node.js, Express.js and MongoDB. I am using a MVC pattern and also have separate file for routes. I am trying me make a Controller class, in which a method calls another method declared within it. But I cannot seem to be able to do this. I get "Cannot read property '' of undefined". index.js file let express = require('express'); let app = express(); let productController = require('../controllers/ProductController'); app.post('/product',