• 減少review code time
• 降低別人動你code 的錯誤機會
• code quality

car.go

package car

import "errors"

// Car struct
type Car struct {
	Name  string
	Price float32
}

// SetName set car name
func (c *Car) SetName(name string) string {
	if name != "" {
		c.Name = name
	}

	return c.Name
}

// New Object
func New(name string, price float32) (*Car, error) {
	if name == "" {
		return nil, errors.New("missing name")
	}

	return &Car{
		Name:  name,
		Price: price,
	}, nil
}

car_test.go

package car

import (
	"testing"
)

// Simple testing what different between Fatal and Error
func TestNew(t *testing.T) {
	c, err := New("", 100)
	if err != nil {
		t.Error("got errors:", err)
	}

	if c == nil {
		t.Error("car should be nil")
	}
}

下command

go test -v