fp-sucks-imperative.js

class CountryUserSelectionStrategy {
  constructor(country) {
    this.country = country;
  }
  
  isMatch(user) {
    return user.country === this.country;
  }
}

class UserSelector {
  constructor(repository, userSelectionStrategy) {
    this.repository = repository;
    this.userSelectionStrategy = userSelectionStrategy;
  }
  
  selectUser() {    
    let user = null;

    for (const u in users) {
      if ( this.userSelectionStrategy.isMatch(u) ) {
        user = u;
        break;
      }
    }
    
    return user;
  }
}

const userRepository = new UserRepository();
const userInitializer = new UserInitializer();
userInitializer.initialize(userRepository);

const americanSelectionStrategy = new CountryUserSelectionStrategy('USA');
const americanUserSelector = new UserSelector(userRepository, americanSelectionStrategy);

const american = americanUserSelector.selectUser();

console.log('American', american);