Merge pull request #3 from azumads/master

support copy slice with ptr struct

copier.go

@@ -4,10 +4,12 @@ import "reflect"
 
 func Copy(copy_to interface{}, copy_from interface{}) (err error) {
 	var (
-		is_slice    bool
-		from_typ    reflect.Type
-		to_typ      reflect.Type
-		elem_amount int
+		is_slice        bool
+		from_typ        reflect.Type
+		is_from_typ_ptr bool
+		to_typ          reflect.Type
+		is_to_typ_ptr   bool
+		elem_amount     int
 	)
 
 	from := reflect.ValueOf(copy_from)
@@ -19,13 +21,22 @@ func Copy(copy_to interface{}, copy_from interface{}) (err error) {
 		is_slice = true
 		if from_elem.Kind() == reflect.Slice {
 			from_typ = from_elem.Type().Elem()
+			if from_typ.Kind() == reflect.Ptr {
+				from_typ = from_typ.Elem()
+				is_from_typ_ptr = true
+			}
 			elem_amount = from_elem.Len()
 		} else {
 			from_typ = from_elem.Type()
 			elem_amount = 1
 		}
 
 		to_typ = to_elem.Type().Elem()
+		if to_typ.Kind() == reflect.Ptr {
+			to_typ = to_typ.Elem()
+			is_to_typ_ptr = true
+		}
+
 	} else {
 		from_typ = from_elem.Type()
 		to_typ = to_elem.Type()
@@ -37,6 +48,9 @@ func Copy(copy_to interface{}, copy_from interface{}) (err error) {
 		if is_slice {
 			if from_elem.Kind() == reflect.Slice {
 				source = from_elem.Index(e)
+				if is_from_typ_ptr {
+					source = source.Elem()
+				}
 			} else {
 				source = from_elem
 			}
@@ -84,7 +98,12 @@ func Copy(copy_to interface{}, copy_from interface{}) (err error) {
 		}
 
 		if is_slice {
-			to_elem.Set(reflect.Append(to_elem, dest))
+			if is_to_typ_ptr {
+				to_elem.Set(reflect.Append(to_elem, dest.Addr()))
+			} else {
+				to_elem.Set(reflect.Append(to_elem, dest))
+			}
+
 		}
 	}
 	return

copier_test.go

@@ -135,6 +135,68 @@ func TestCopySlice(t *testing.T) {
 	}
 }
 
+func TestCopySliceWithPtr(t *testing.T) {
+	user := User{Name: "Jinzhu", Age: 18, Role: "Admin", Notes: []string{"hello world"}}
+	user2 := &User{Name: "jinzhu 2", Age: 30, Role: "Dev"}
+	users := []*User{user2}
+	employees := []*Employee{}
+
+	Copy(&employees, &user)
+	if len(employees) != 1 {
+		t.Errorf("Should only have one elem when copy struct to slice")
+	}
+
+	Copy(&employees, &users)
+	if len(employees) != 2 {
+		t.Errorf("Should have two elems when copy additional slice to slice")
+	}
+
+	if employees[0].Name != "Jinzhu" {
+		t.Errorf("Name haven't been copied correctly.")
+	}
+	if employees[0].Age != 18 {
+		t.Errorf("Age haven't been copied correctly.")
+	}
+	if employees[0].DoubleAge != 36 {
+		t.Errorf("Copy copy from method doesn't work")
+	}
+	if employees[0].SuperRule != "Super Admin" {
+		t.Errorf("Copy Attributes should support copy to method")
+	}
+
+	if employees[1].Name != "jinzhu 2" {
+		t.Errorf("Name haven't been copied correctly.")
+	}
+	if employees[1].Age != 30 {
+		t.Errorf("Age haven't been copied correctly.")
+	}
+	if employees[1].DoubleAge != 60 {
+		t.Errorf("Copy copy from method doesn't work")
+	}
+	if employees[1].SuperRule != "Super Dev" {
+		t.Errorf("Copy Attributes should support copy to method")
+	}
+
+	employee := employees[0]
+	user.Notes = append(user.Notes, "welcome")
+	if !reflect.DeepEqual(user.Notes, []string{"hello world", "welcome"}) {
+		t.Errorf("User's Note should be changed")
+	}
+
+	if !reflect.DeepEqual(employee.Notes, []string{"hello world"}) {
+		t.Errorf("Employee's Note should not be changed")
+	}
+
+	employee.Notes = append(employee.Notes, "golang")
+	if !reflect.DeepEqual(employee.Notes, []string{"hello world", "golang"}) {
+		t.Errorf("Employee's Note should be changed")
+	}
+
+	if !reflect.DeepEqual(user.Notes, []string{"hello world", "welcome"}) {
+		t.Errorf("Employee's Note should not be changed")
+	}
+}
+
 func BenchmarkCopyStruct(b *testing.B) {
 	user := User{Name: "Jinzhu", Age: 18, Role: "Admin", Notes: []string{"hello world"}}
 	for x := 0; x < b.N; x++ {