tewtutin_4.ts

// ...
async makeRemittance(fromId: number, toId: number, sum: number, withError = false, transaction = true): Promise<RemittanceResultDto> {  
  const fromUser = await this.userRepository.findOne(fromId, { transaction });  
  const toUser = await this.userRepository.findOne(toId, { transaction });  
  if (fromUser === undefined) {  
    throw new Error(NOT_FOUND_USER_WITH_ID(fromId));  
  }  
  if (toUser === undefined) {  
    throw new Error(NOT_FOUND_USER_WITH_ID(toId));  
  }  
  if (fromUser.defaultPurseId === null) {  
    throw new Error(USER_DOES_NOT_HAVE_PURSE(fromId));  
  }  
  if (toUser.defaultPurseId === null) {  
    throw new Error(USER_DOES_NOT_HAVE_PURSE(toId));  
  }  
  const fromPurse = await this.purseRepository.findOne(fromUser.defaultPurseId, { transaction });  
  const toPurse = await this.purseRepository.findOne(toUser.defaultPurseId, { transaction });  
  const modalSum = Math.abs(sum);  
  if (fromPurse.balance < modalSum) {  
    throw new Error(NOT_ENOUGH_MONEY(fromId));  
  }  
  fromPurse.balance -= sum;  
  toPurse.balance += sum;  
  await this.purseRepository.save(fromPurse, { transaction });  
  if (withError) {  
    throw new Error('Unexpectable error was thrown while remittance');  
  }  
  await this.purseRepository.save(toPurse, { transaction });  
  const remittance = new RemittanceResultDto();  
  remittance.fromId = fromId;  
  remittance.toId = toId;  
  remittance.fromBalance = fromPurse.balance;  
  remittance.sum = sum;  
  return remittance;  
}
// ...