PaymentsRepositoryHelper2.js

import {when} from "jest-when";

export function stub(paymentsRepository) {
  const monthPaymentsBuilder = {
    inMonth: inMonth
  };

  return knowingThat;

  function knowingThat() {
    return monthPaymentsBuilder;
  }

  function inMonth(month) {
    return {
      userWith: (userId) => {
        return {
          hasPaid: (payments) => {
            when(paymentsRepository.find).calledWith(userId, month)
              .mockReturnValue(payments);
            return {
              andThat: knowingThat
            };
          }
        };
      }
    };
  }
}