From be3229dfd12a79f742330d6a5d1e760fbf230807 Mon Sep 17 00:00:00 2001
From: Tom Bevan <tom.bevan@r3labs.io>
Date: Thu, 16 Dec 2021 12:09:57 +0000
Subject: [PATCH] fix pointers when convert types is enabled

---
 change_value.go | 25 ++++++++++++++++++++-----
 patch_test.go   | 30 ++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/change_value.go b/change_value.go
index 156b6aa..529554b 100644
--- a/change_value.go
+++ b/change_value.go
@@ -118,12 +118,27 @@ func (c *ChangeValue) Set(value reflect.Value, convertCompatibleTypes bool) {
 		}
 
 		if convertCompatibleTypes {
-			if !value.Type().ConvertibleTo(c.target.Type()) {
-				c.AddError(fmt.Errorf("Value of type %s is not convertible to %s", value.Type().String(), c.target.Type().String()))
-				c.SetFlag(FlagFailed)
-				return
+			if c.target.Kind() == reflect.Ptr && value.Kind() != reflect.Ptr {
+				if !value.Type().ConvertibleTo(c.target.Elem().Type()) {
+					c.AddError(fmt.Errorf("Value of type %s is not convertible to %s", value.Type().String(), c.target.Type().String()))
+					c.SetFlag(FlagFailed)
+					return
+				}
+
+				fmt.Println(c.target.Elem().Type())
+
+				tv := reflect.New(c.target.Elem().Type())
+				tv.Elem().Set(value.Convert(c.target.Elem().Type()))
+				c.target.Set(tv)
+			} else {
+				if !value.Type().ConvertibleTo(c.target.Type()) {
+					c.AddError(fmt.Errorf("Value of type %s is not convertible to %s", value.Type().String(), c.target.Type().String()))
+					c.SetFlag(FlagFailed)
+					return
+				}
+
+				c.target.Set(value.Convert(c.target.Type()))
 			}
-			c.target.Set(value.Convert(c.target.Type()))
 		} else {
 			if value.IsValid() {
 				if c.target.Kind() == reflect.Ptr && value.Kind() != reflect.Ptr {
diff --git a/patch_test.go b/patch_test.go
index 63fd69a..bb69e7a 100644
--- a/patch_test.go
+++ b/patch_test.go
@@ -1,6 +1,7 @@
 package diff_test
 
 import (
+	"encoding/json"
 	"testing"
 	"time"
 
@@ -303,3 +304,32 @@ func TestPatchPointer(t *testing.T) {
 	patchLog := diff.Patch(changelog, &t1)
 	assert.False(t, patchLog.HasErrors())
 }
+
+func TestPatchPointerConvertTypes(t *testing.T) {
+	type tps struct {
+		S *int
+	}
+
+	val1 := 1
+	val2 := 2
+
+	t1 := tps{S: &val1}
+	t2 := tps{S: &val2}
+
+	changelog, err := diff.Diff(t1, t2)
+	assert.NoError(t, err)
+
+	js, err := json.Marshal(changelog)
+	assert.NoError(t, err)
+
+	assert.NoError(t, json.Unmarshal(js, &changelog))
+
+	d, err := diff.NewDiffer(diff.ConvertCompatibleTypes())
+	assert.NoError(t, err)
+
+	assert.Equal(t, 1, *t1.S)
+
+	patchLog := d.Patch(changelog, &t1)
+	assert.False(t, patchLog.HasErrors())
+	assert.Equal(t, 2, *t1.S)
+}