Add validation for user fields

Integrated validation for "name" and "email" fields in user models. Updated the UserHandler to register custom validators using go-playground/validator. Added custom error messages for validation to improve clarity for users.

cmd/api/main.go

@@ -41,7 +41,7 @@ func main() {
 
 	// User
 	userService := usr.NewUserService(db, env)
-	user.NewUserHandler(s, "/user", userService)
+	user.NewUserHandler(s, "/user", userService, validate)
 
 	// Restaurant
 	restaurantService := restro.NewRestaurantService(db, env)

pkg/database/models/user/user.go

@@ -1,16 +1,19 @@
 package user
 
 import (
+	"errors"
+	"github.com/go-playground/validator/v10"
 	"github.com/uptrace/bun"
 	"golang.org/x/crypto/bcrypt"
 	"log"
+	"regexp"
 )
 
 type User struct {
 	bun.BaseModel `bun:"table:users"`
 	ID            int64  `bun:",pk,autoincrement" json:"id"`
-	Name          string `bun:",notnull" json:"name"`
-	Email         string `bun:",unique,notnull" json:"email"`
+	Name          string `bun:",notnull" json:"name" validate:"name"`
+	Email         string `bun:",unique,notnull" json:"email" validate:"email"`
 	Password      string `bun:",notnull" json:"password"`
 }
 
@@ -30,3 +33,39 @@ func (u *User) HashPassword() {
 func (l *LoginUser) CheckPassword(hashPassword string) error {
 	return bcrypt.CompareHashAndPassword([]byte(hashPassword), []byte(l.Password))
 }
+
+func NameValidator(fl validator.FieldLevel) bool {
+	str, ok := fl.Field().Interface().(string)
+	return ok && str != ""
+}
+
+func EmailValidator(fl validator.FieldLevel) bool {
+	email, ok := fl.Field().Interface().(string)
+	if !ok {
+		return false
+	}
+	// Basic email regex pattern
+	re := regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`)
+	return re.MatchString(email)
+}
+
+func UserValidationError(err error) map[string]string {
+	var validationErrors validator.ValidationErrors
+	if !errors.As(err, &validationErrors) {
+		return map[string]string{"error": "Unknown error"}
+	}
+
+	errorsMap := make(map[string]string)
+	for _, e := range validationErrors {
+		field := e.Field()
+		switch e.Tag() {
+		case "name":
+			errorsMap[field] = "Provide your full name"
+		case "email":
+			errorsMap[field] = "Provide valid email address"
+		default:
+			errorsMap[field] = "Invalid"
+		}
+	}
+	return errorsMap
+}

pkg/handler/user/service.go

@@ -1,26 +1,36 @@
 package user
 
 import (
+	userValidate "Go_Food_Delivery/pkg/database/models/user"
 	"Go_Food_Delivery/pkg/handler"
 	"Go_Food_Delivery/pkg/service/user"
 	"github.com/gin-gonic/gin"
+	"github.com/go-playground/validator/v10"
 )
 
 type UserHandler struct {
-	Serve   *handler.Server
-	group   string
-	router  *gin.RouterGroup
-	service *user.UsrService
+	Serve    *handler.Server
+	group    string
+	router   *gin.RouterGroup
+	service  *user.UsrService
+	validate *validator.Validate
 }
 
-func NewUserHandler(s *handler.Server, groupName string, service *user.UsrService) {
+func NewUserHandler(s *handler.Server, groupName string, service *user.UsrService, validate *validator.Validate) {
 
 	usrHandler := &UserHandler{
 		s,
 		groupName,
 		&gin.RouterGroup{},
 		service,
+		validate,
 	}
 	usrHandler.router = usrHandler.registerGroup()
 	usrHandler.routes()
+	usrHandler.registerValidator()
+}
+
+func (s *UserHandler) registerValidator() {
+	_ = s.validate.RegisterValidation("name", userValidate.NameValidator)
+	_ = s.validate.RegisterValidation("email", userValidate.EmailValidator)
 }

pkg/handler/user/user.go

@@ -20,6 +20,12 @@ func (s *UserHandler) addUser(c *gin.Context) {
 		return
 	}
 
+	if err := s.validate.Struct(user); err != nil {
+		validationError := userModel.UserValidationError(err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": validationError})
+		return
+	}
+
 	_, err := s.service.Add(ctx, &user)
 	if err != nil {
 		c.AbortWithStatusJSON(http.StatusNotFound, gin.H{"error": err.Error()})