go_workshop/chapter_06/activity_6.03/main.go

package main

import (
  "errors"
  "fmt"
  "strings"
)

type directDeposit struct {
  lastName      string
  firstName     string
  bankName      string
  routingNumber int
  accountNumber int
}

var (
  ErrInvalidLastName      = errors.New("invalid last name")
  ErrInvalidRoutingNumber = errors.New("invalid routing number")
)

func (d *directDeposit) validateRoutingNumber() error {

  if d.routingNumber < 100 {
    panic(ErrInvalidRoutingNumber)
  }
  return nil

}

func (d *directDeposit) validateLastName() error {

  d.lastName = strings.TrimSpace(d.lastName)
  if len(d.lastName) == 0 {
    return ErrInvalidLastName
  }
  return nil

}

func (d *directDeposit) report() {

  fmt.Println(strings.Repeat("*", 40))
  fmt.Println("Last Name:     ", d.lastName)
  fmt.Println("First Name:    ", d.firstName)
  fmt.Println("Bank Name:     ", d.bankName)
  fmt.Println("Routing Number:", d.routingNumber)
  fmt.Println("Account Number:", d.accountNumber)

}

func main() {

  dp := directDeposit{
    "",
    "Abe",
    "XYZ Inc",
    17,
    1809,
  }

  _ = dp.validateRoutingNumber()
  if err := dp.validateLastName(); err != nil {
    fmt.Println(err)
  }
  dp.report()

}