嵌套结构体无法使用copier:"-"忽略复制

[liushuai05]

Reproducible Example

https://go.dev/play/p/tZZ6N4beaTV

Description

嵌套结构体无法使用copier:"-"忽略复制，不嵌套的情况下是可以的参考上面的demo或如下代码片，不知道实现难度如何，但这个可能很有必要大佬，因为很多人写结构体对应数据库都是CreatedAt和UpdateAt什么的只写一次然后采用gorm自动维护，其他地方嵌套进去，但是gorm自动维护好像得是nil才行

这种情况无法忽略，会把source.CreatedAt 复制给target
package main

import (
	"fmt"
	"time"

	"github.com/jinzhu/copier"
)
 
type Timestamps struct {
	CreatedAt *time.Time `gorm:"type:datetime;not null;default:CURRENT_TIMESTAMP" copier:"-"`
}

type Source struct {
	Timestamps
	Name   string
	Secret string // We do not want this to be copied.
}

type Target struct {
	Timestamps
	Name   string
	Secret string `copier:"-"`
}

func main() {
	var source Source
	source.Name = "John"
	source.Secret = "so_secret"

	times := time.Now()
	source.CreatedAt = &times

	target := Target{}

	copier.Copy(&target, &source)
	fmt.Printf("Name: %s, Secret: '%s' ,CreatedAt:'%s'\n", target.Name, target.Secret, target.CreatedAt)
	// Output: Name: John, Secret: '' ,CreatedAt:'2024-11-07 10:17:43.180809558 +0800 CST m=+0.000030354'
}

下面这种情况就很好

package main

import (
	"fmt"
	"time"

	"github.com/jinzhu/copier"
)

type Source struct {
	CreatedAt *time.Time `gorm:"type:datetime;not null;default:CURRENT_TIMESTAMP" copier:"-"`
	Name   string
	Secret string // We do not want this to be copied.
}

type Target struct {
	CreatedAt *time.Time `gorm:"type:datetime;not null;default:CURRENT_TIMESTAMP" copier:"-"`
	Name   string
	Secret string `copier:"-"`
}

func main() {
	var source Source
	source.Name = "John"
	source.Secret = "so_secret"

	times := time.Now()
	source.CreatedAt = &times

	target := Target{}

	copier.Copy(&target, &source)
	fmt.Printf("Name: %s, Secret: '%s' ,CreatedAt:'%s'\n", target.Name, target.Secret, target.CreatedAt)
	// Output: Name: John, Secret: '' ,CreatedAt:'<nil>'
}