fix: 🐛 embedded struct test failed with custom datatypes (#6311)

* fix: 🐛 embedded struct test failed with custom datatypes

Fix the pointer embedded struct within custom datatypes and *time.time
should be nil issue.

* fix: 🐛 change test case to avoid mssql driver issue

change test cases from bytes to string to avoid mssql driver issue

schema/field.go

@@ -846,7 +846,7 @@ func (field *Field) setupValuerAndSetter() {
 			field.Set = func(ctx context.Context, value reflect.Value, v interface{}) error {
 				switch data := v.(type) {
 				case **time.Time:
-					if data != nil {
+					if data != nil && *data != nil {
 						field.ReflectValueOf(ctx, value).Set(reflect.ValueOf(*data))
 					}
 				case time.Time:
@@ -882,14 +882,12 @@ func (field *Field) setupValuerAndSetter() {
 					reflectV := reflect.ValueOf(v)
 					if !reflectV.IsValid() {
 						field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
+					} else if reflectV.Kind() == reflect.Ptr && reflectV.IsNil() {
+						return
 					} else if reflectV.Type().AssignableTo(field.FieldType) {
 						field.ReflectValueOf(ctx, value).Set(reflectV)
 					} else if reflectV.Kind() == reflect.Ptr {
-						if reflectV.IsNil() || !reflectV.IsValid() {
-							field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
-						} else {
-							return field.Set(ctx, value, reflectV.Elem().Interface())
-						}
+						return field.Set(ctx, value, reflectV.Elem().Interface())
 					} else {
 						fieldValue := field.ReflectValueOf(ctx, value)
 						if fieldValue.IsNil() {
@@ -910,14 +908,12 @@ func (field *Field) setupValuerAndSetter() {
 					reflectV := reflect.ValueOf(v)
 					if !reflectV.IsValid() {
 						field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
+					} else if reflectV.Kind() == reflect.Ptr && reflectV.IsNil() {
+						return
 					} else if reflectV.Type().AssignableTo(field.FieldType) {
 						field.ReflectValueOf(ctx, value).Set(reflectV)
 					} else if reflectV.Kind() == reflect.Ptr {
-						if reflectV.IsNil() || !reflectV.IsValid() {
-							field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
-						} else {
-							return field.Set(ctx, value, reflectV.Elem().Interface())
-						}
+						return field.Set(ctx, value, reflectV.Elem().Interface())
 					} else {
 						if valuer, ok := v.(driver.Valuer); ok {
 							v, _ = valuer.Value()

tests/embedded_struct_test.go

@@ -4,7 +4,9 @@ import (
 	"database/sql/driver"
 	"encoding/json"
 	"errors"
+	"reflect"
 	"testing"
+	"time"
 
 	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
@@ -104,10 +106,14 @@ func TestEmbeddedPointerTypeStruct(t *testing.T) {
 	}
 
 	type Author struct {
-		ID    string
-		Name  string
-		Email string
-		Age   int
+		ID          string
+		Name        string
+		Email       string
+		Age         int
+		Content     Content
+		ContentPtr  *Content
+		Birthday    time.Time
+		BirthdayPtr *time.Time
 	}
 
 	type HNPost struct {
@@ -135,6 +141,48 @@ func TestEmbeddedPointerTypeStruct(t *testing.T) {
 	if hnPost.Author != nil {
 		t.Errorf("Expected to get back a nil Author but got: %v", hnPost.Author)
 	}
+
+	now := time.Now().Round(time.Second)
+	NewPost := HNPost{
+		BasePost: &BasePost{Title: "embedded_pointer_type2"},
+		Author: &Author{
+			Name:        "test",
+			Content:     Content{"test"},
+			ContentPtr:  nil,
+			Birthday:    now,
+			BirthdayPtr: nil,
+		},
+	}
+	DB.Create(&NewPost)
+
+	hnPost = HNPost{}
+	if err := DB.First(&hnPost, "title = ?", NewPost.Title).Error; err != nil {
+		t.Errorf("No error should happen when find embedded pointer type, but got %v", err)
+	}
+
+	if hnPost.Title != NewPost.Title {
+		t.Errorf("Should find correct value for embedded pointer type")
+	}
+
+	if hnPost.Author.Name != NewPost.Author.Name {
+		t.Errorf("Expected to get Author name %v but got: %v", NewPost.Author.Name, hnPost.Author.Name)
+	}
+
+	if !reflect.DeepEqual(NewPost.Author.Content, hnPost.Author.Content) {
+		t.Errorf("Expected to get Author content %v but got: %v", NewPost.Author.Content, hnPost.Author.Content)
+	}
+
+	if hnPost.Author.ContentPtr != nil {
+		t.Errorf("Expected to get nil Author contentPtr but got: %v", hnPost.Author.ContentPtr)
+	}
+
+	if NewPost.Author.Birthday.UnixMilli() != hnPost.Author.Birthday.UnixMilli() {
+		t.Errorf("Expected to get Author birthday with %+v but got: %+v", NewPost.Author.Birthday, hnPost.Author.Birthday)
+	}
+
+	if hnPost.Author.BirthdayPtr != nil {
+		t.Errorf("Expected to get nil Author birthdayPtr but got: %+v", hnPost.Author.BirthdayPtr)
+	}
 }
 
 type Content struct {
@@ -142,18 +190,26 @@ type Content struct {
 }
 
 func (c Content) Value() (driver.Value, error) {
-	return json.Marshal(c)
+	// mssql driver with issue on handling null bytes https://github.com/denisenkom/go-mssqldb/issues/530,
+	b, err := json.Marshal(c)
+	return string(b[:]), err
 }
 
 func (c *Content) Scan(src interface{}) error {
-	b, ok := src.([]byte)
-	if !ok {
-		return errors.New("Embedded.Scan byte assertion failed")
-	}
-
 	var value Content
-	if err := json.Unmarshal(b, &value); err != nil {
-		return err
+	str, ok := src.(string)
+	if !ok {
+		byt, ok := src.([]byte)
+		if !ok {
+			return errors.New("Embedded.Scan byte assertion failed")
+		}
+		if err := json.Unmarshal(byt, &value); err != nil {
+			return err
+		}
+	} else {
+		if err := json.Unmarshal([]byte(str), &value); err != nil {
+			return err
+		}
 	}
 
 	*c = value