facade_pattern.js

// Here AccountManager is responsible to create new account of type 
// Savings or Current with the unique account number
let currentAccountNumber = 0;

class AccountManager {
 createAccount(type, details) {
   const accountNumber = AccountManager.getUniqueAccountNumber();
   let account;
   if (type === 'current') {
     account = new CurrentAccount();
   } else {
     account = new SavingsAccount();
   }
   return account.addAccount({ accountNumber, details });
 }
 
 static getUniqueAccountNumber() {
   return ++currentAccountNumber;
 }
}


// class Accounts maintains the list of all accounts created
class Accounts {
 constructor() {
   this.accounts = [];
 }
 
 addAccount(account) {
   this.accounts.push(account);
   return this.successMessage(complaint);
 }
 
 getAccount(accountNumber) {
   return this.accounts.find(account => account.accountNumber === accountNumber);
 }
 
 successMessage(account) {}
}

// CurrentAccounts extends the implementation of Accounts for providing more specific success messages on successful account creation
class CurrentAccounts extends Accounts {
 constructor() {
   super();
   if (CurrentAccounts.exists) {
     return CurrentAccounts.instance;
   }
   CurrentAccounts.instance = this;
   CurrentAccounts.exists = true;
   return this;
 }
 
 successMessage({ accountNumber, details }) {
   return `Current Account created with ${details}. ${accountNumber} is your account number.`;
 }
}
 
// Same here, SavingsAccount extends the implementation of Accounts for providing more specific success messages on successful account creation
class SavingsAccount extends Accounts {
 constructor() {
   super();
   if (SavingsAccount.exists) {
     return SavingsAccount.instance;
   }
   SavingsAccount.instance = this;
   SavingsAccount.exists = true;
   return this;
 }
 
 successMessage({ accountNumber, details }) {
   return `Savings Account created with ${details}. ${accountNumber} is your account number.`;
 }
}
 
// usage
// Here we are hiding the complexities of creating account
const accountManager = new AccountManager();
 
const currentAccount = accountManager.createAccount('current', { name: 'John Snow', address: 'pune' });
 
const savingsAccount = accountManager.createAccount('savings', { name: 'Petter Kim', address: 'mumbai' });