From 2701698e6e91e6130de5bf17ac93c6eec85eb652 Mon Sep 17 00:00:00 2001
From: 5aaee9 <7685264+5aaee9@users.noreply.github.com>
Date: Wed, 7 Jun 2023 06:07:14 +0000
Subject: [PATCH] objects: add RemarshJSONReflect

---
 pkgs/objects/json.go      | 44 ++++++++++++++++++++++++++++++++++++++-
 pkgs/objects/json_test.go | 19 +++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/pkgs/objects/json.go b/pkgs/objects/json.go
index 012d0e4..b18eb5c 100644
--- a/pkgs/objects/json.go
+++ b/pkgs/objects/json.go
@@ -1,6 +1,10 @@
 package objects
 
-import "encoding/json"
+import (
+	"encoding/json"
+	"errors"
+	"reflect"
+)
 
 func RemarshJSON[T any](input any) (*T, error) {
 	bytes, err := json.Marshal(input)
@@ -15,3 +19,41 @@ func RemarshJSON[T any](input any) (*T, error) {
 
 	return r, nil
 }
+
+var ErrTypeError = errors.New("type error")
+
+func RemarshJSONReflect[T any](input any, kind reflect.Type) (*T, error) {
+	data, err := json.Marshal(input)
+	if err != nil {
+		return nil, err
+	}
+
+	if kind.Kind() == reflect.Ptr {
+		typ := kind.Elem()
+		dst := reflect.New(typ).Elem()
+		err := json.Unmarshal(data, dst.Addr().Interface())
+		if err != nil {
+			return nil, err
+		}
+
+		res, ok := dst.Addr().Interface().(*T)
+		if !ok {
+			return nil, ErrTypeError
+		}
+
+		return res, nil
+	}
+
+	dst := reflect.New(kind).Elem()
+	err = json.Unmarshal(data, dst.Addr().Interface())
+	if err != nil {
+		return nil, err
+	}
+
+	res, ok := dst.Interface().(T)
+	if !ok {
+		return nil, ErrTypeError
+	}
+
+	return &res, nil
+}
diff --git a/pkgs/objects/json_test.go b/pkgs/objects/json_test.go
index ad74df8..f1538ba 100644
--- a/pkgs/objects/json_test.go
+++ b/pkgs/objects/json_test.go
@@ -1,6 +1,7 @@
 package objects_test
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/5aaee9/utils/pkgs/json"
@@ -20,3 +21,21 @@ func TestRemarshJSON(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, out.Data, "data test #1")
 }
+
+func TestRemarshJSONReflect(t *testing.T) {
+	out, err := objects.RemarshJSONReflect[TestStruct](json.JSON{
+		"test": "data test #1",
+	}, reflect.TypeOf(TestStruct{}))
+
+	assert.NoError(t, err)
+	assert.Equal(t, out.Data, "data test #1")
+
+	ptr := new(TestStruct)
+
+	out, err = objects.RemarshJSONReflect[TestStruct](json.JSON{
+		"test": "data test #1",
+	}, reflect.ValueOf(ptr).Type())
+	assert.NoError(t, err)
+	assert.Equal(t, out.Data, "data test #1")
+	assert.Equal(t, ptr.Data, "")
+}