refactor🎨: move app/demo onto the generic actions

The five routes use actions.Index, View, Create, Update and Delete. The
control request's GenerateM becomes ToModel, returning the model type
itself, and the Generate methods on the model and the three request
types go, along with the tests that held them to returning copies:
nothing calls them any more.

Recorded before the change and replayed after it, the same 18 requests
- creates, lists with filters and paging, details, updates and deletes,
found and missing - get byte-identical responses.

app/demo/models/demo_product.go

@@ -25,13 +25,6 @@ func (DemoProduct) TableName() string {
 	return "demo_product"
 }
 
-// Generate 返回副本，供通用 Action 使用。
-// 必须返回新实例：Action 在并发请求间复用同一个模型指针，就地返回会串数据。
-func (e *DemoProduct) Generate() models.ActiveRecord {
-	o := *e
-	return &o
-}
-
 func (e *DemoProduct) GetId() interface{} {
 	return e.Id
 }

app/demo/router/demo_product.go

@@ -29,21 +29,12 @@ func registerDemoProductRouter(v1 *gin.RouterGroup, authMiddleware *jwt.GinJWTMi
 		Use(authMiddleware.MiddlewareFunc()). // JWT 认证
 		Use(middleware.AuthCheckRole())       // Casbin 鉴权
 	{
-		m := &models.DemoProduct{}
-
 		// actions.PermissionAction() 注入数据权限上下文，
 		// 列表与详情缺少它会绕过 DataScope 过滤
-		r.GET("", actions.PermissionAction(), actions.IndexAction(m, new(dto.DemoProductSearch), func() interface{} {
-			list := make([]models.DemoProduct, 0)
-			return &list
-		}))
-
-		r.GET("/:id", actions.PermissionAction(), actions.ViewAction(new(dto.DemoProductById), func() interface{} {
-			return &models.DemoProduct{}
-		}))
-
-		r.POST("", actions.CreateAction(new(dto.DemoProductControl)))
-		r.PUT("/:id", actions.PermissionAction(), actions.UpdateAction(new(dto.DemoProductControl)))
-		r.DELETE("", actions.PermissionAction(), actions.DeleteAction(new(dto.DemoProductById)))
+		r.GET("", actions.PermissionAction(), actions.Index[models.DemoProduct, dto.DemoProductSearch]())
+		r.GET("/:id", actions.PermissionAction(), actions.View[models.DemoProduct, dto.DemoProductById]())
+		r.POST("", actions.Create[models.DemoProduct, dto.DemoProductControl]())
+		r.PUT("/:id", actions.PermissionAction(), actions.Update[models.DemoProduct, dto.DemoProductControl]())
+		r.DELETE("", actions.PermissionAction(), actions.Delete[models.DemoProduct, dto.DemoProductById]())
 	}
 }

app/demo/service/dto/demo_product.go

@@ -36,15 +36,10 @@ func (m *DemoProductSearch) Bind(ctx *gin.Context) error {
 	return ctx.ShouldBind(m)
 }
 
-func (m *DemoProductSearch) Generate() dto.Index {
-	o := *m
-	return &o
-}
-
-// DemoProductControl 新增与修改共用的入参
+// DemoProductControl is the request body of both create and update.
 //
-// 通用 Action（Create / Update）通过 GenerateM 拿到落库对象，
-// 因此这里不直接暴露 Model，字段校验用 validate tag 声明。
+// actions.Create / actions.Update get the row to write from ToModel, so the
+// model itself is not exposed; field rules are declared with validate tags.
 type DemoProductControl struct {
 	Id     int     `json:"id" comment:"主键"`
 	Name   string  `json:"name" comment:"名称" validate:"required"`
@@ -58,16 +53,9 @@ func (s *DemoProductControl) Bind(ctx *gin.Context) error {
 	return ctx.ShouldBind(s)
 }
 
-func (s *DemoProductControl) Generate() dto.Control {
-	o := *s
-	return &o
-}
-
-func (s *DemoProductControl) GetId() interface{} { return s.Id }
-
-// GenerateM 组装落库对象。CreateBy / UpdateBy 由通用 Action 在此之后注入，
-// 此处不要手动赋值。
-func (s *DemoProductControl) GenerateM() (common.ActiveRecord, error) {
+// ToModel builds the row to write. The actions set CreateBy / UpdateBy
+// afterwards, so do not set them here.
+func (s *DemoProductControl) ToModel() (*models.DemoProduct, error) {
 	return &models.DemoProduct{
 		Model:  common.Model{Id: s.Id},
 		Name:   s.Name,
@@ -85,12 +73,3 @@ type DemoProductById struct {
 
 // Bind 与 GetId 由内嵌的 dto.ObjectById 提供：它已处理好 uri 绑定、
 // DELETE 时的批量 ids 合并与参数校验，无需在此重复实现。
-
-func (s *DemoProductById) Generate() dto.Control {
-	o := *s
-	return &o
-}
-
-func (s *DemoProductById) GenerateM() (common.ActiveRecord, error) {
-	return &models.DemoProduct{}, nil
-}

app/demo/service/dto/demo_product_test.go

@@ -4,83 +4,21 @@ import (
 	"testing"
 
 	"go-admin/app/demo/models"
-	"go-admin/common/dto"
-	common "go-admin/common/models"
 )
 
-// 通用 Action 依赖 DTO 与 Model 实现一组接口。这些约束在编译期无法完全覆盖
-// （接口是在路由注册处才被要求的），因此用测试锁定，避免改动后在运行时才暴露。
-
-func TestImplementsIndexInterface(t *testing.T) {
-	var _ dto.Index = (*DemoProductSearch)(nil)
-}
-
-func TestImplementsControlInterface(t *testing.T) {
-	var _ dto.Control = (*DemoProductControl)(nil)
-	var _ dto.Control = (*DemoProductById)(nil)
-}
-
-func TestModelImplementsActiveRecord(t *testing.T) {
-	var _ common.ActiveRecord = (*models.DemoProduct)(nil)
-}
-
-// Generate 必须返回副本：通用 Action 在并发请求间复用同一个实例，
-// 就地返回会导致请求之间串数据。
-func TestGenerateReturnsCopy(t *testing.T) {
-	src := &DemoProductControl{Id: 1, Name: "原始"}
-	got := src.Generate().(*DemoProductControl)
-
-	if got == src {
-		t.Fatal("Generate 返回了同一指针，应返回副本")
-	}
-	got.Name = "被修改"
-	if src.Name != "原始" {
-		t.Errorf("修改副本影响了原对象：src.Name = %q", src.Name)
-	}
-}
-
-func TestSearchGenerateReturnsCopy(t *testing.T) {
-	src := &DemoProductSearch{Name: "原始"}
-	got := src.Generate().(*DemoProductSearch)
-
-	if got == src {
-		t.Fatal("Generate 返回了同一指针，应返回副本")
-	}
-	got.Name = "被修改"
-	if src.Name != "原始" {
-		t.Errorf("修改副本影响了原对象：src.Name = %q", src.Name)
-	}
-}
-
-func TestModelGenerateReturnsCopy(t *testing.T) {
-	src := &models.DemoProduct{Name: "原始"}
-	got := src.Generate().(*models.DemoProduct)
-
-	if got == src {
-		t.Fatal("Generate 返回了同一指针，应返回副本")
-	}
-	got.Name = "被修改"
-	if src.Name != "原始" {
-		t.Errorf("修改副本影响了原对象：src.Name = %q", src.Name)
-	}
-}
-
-// GenerateM 组装落库对象，主键需正确传递，否则更新会退化成插入。
-func TestGenerateMCarriesId(t *testing.T) {
+// ToModel builds the row to write; the key has to reach it, or an update
+// matches no row.
+func TestToModelCarriesId(t *testing.T) {
 	c := &DemoProductControl{Id: 42, Name: "示例", Code: "P-42", Price: 9.9}
-	m, err := c.GenerateM()
+	p, err := c.ToModel()
 	if err != nil {
-		t.Fatalf("GenerateM 返回错误: %v", err)
-	}
-	p, ok := m.(*models.DemoProduct)
-	if !ok {
-		t.Fatalf("GenerateM 返回类型错误: %T", m)
+		t.Fatalf("ToModel: %v", err)
 	}
 	if p.Id != 42 {
-		t.Errorf("主键未传递: got %d, want 42", p.Id)
+		t.Errorf("key not carried: got %d, want 42", p.Id)
 	}
 	if p.Name != "示例" || p.Code != "P-42" || p.Price != 9.9 {
-		t.Errorf("字段映射有误: %+v", p)
+		t.Errorf("fields mapped wrongly: %+v", p)
 	}
 }