sequelizs-db-conn.js

const DbConfig = require('../config');
const Sequelize = require('sequelize');

class DatabaseConfig {
  
  /**
   * @type {import('sequelize').Sequelize}
   */
  databaseClient = {};

  constructor() {

    switch(DbConfig.environment.toLocaleLowerCase()) {
      case 'development':
        this.databaseClient = new Sequelize(
          DbConfig.development.database,
          DbConfig.development.username,
          DbConfig.development.password,
          DbConfig.development
        );
        break;
      case 'test':
        this.databaseClient = new Sequelize(
          DbConfig.test.database,
          DbConfig.test.username,
          DbConfig.test.password,
          DbConfig.test
        );
        break;
      case 'production':
        this.databaseClient = new Sequelize(
          DbConfig.production.database,
          DbConfig.production.username,
          DbConfig.production.password,
          DbConfig.production
        );
        break;
      default:
        this.databaseClient = new Sequelize(
          DbConfig.development.database,
          DbConfig.development.username,
          DbConfig.development.password,
          DbConfig.development
        );
        break;
    }
  }
}

module.exports = new DatabaseConfig().databaseClient;