From 6ea332de897903e19d7750dd28256d864426f9f0 Mon Sep 17 00:00:00 2001
From: spetrunin <neyasut@gmail.com>
Date: Thu, 14 Nov 2024 23:35:51 +0200
Subject: [PATCH] fix: fix merging of response nodes of enum type

---
 .../engine/postprocess/merge_fields_test.go   | 108 +++++++++++++++++-
 v2/pkg/engine/resolve/node_enum.go            |   9 +-
 2 files changed, 112 insertions(+), 5 deletions(-)

diff --git a/v2/pkg/engine/postprocess/merge_fields_test.go b/v2/pkg/engine/postprocess/merge_fields_test.go
index ee0a666657..948f84c94c 100644
--- a/v2/pkg/engine/postprocess/merge_fields_test.go
+++ b/v2/pkg/engine/postprocess/merge_fields_test.go
@@ -4,16 +4,17 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/engine/resolve"
 )
 
 func TestMergeFields_Process(t *testing.T) {
 
-	runTest := func(in, out resolve.Node) func(t *testing.T) {
+	runTest := func(in, expected resolve.Node) func(t *testing.T) {
 		return func(t *testing.T) {
 			m := &mergeFields{}
 			m.Process(in)
-			assert.Equal(t, out, in)
+			assert.Equal(t, expected, in)
 		}
 	}
 
@@ -43,6 +44,109 @@ func TestMergeFields_Process(t *testing.T) {
 		},
 	))
 
+	t.Run("merge enum fields", runTest(
+		&resolve.Object{
+			Fields: []*resolve.Field{
+				{
+					Name: []byte(`interfaceField`),
+					Value: &resolve.Object{
+						Fields: []*resolve.Field{
+							{
+								Name: []byte(`enumField`),
+								Value: &resolve.Enum{
+									Values:             []string{`a`},
+									InaccessibleValues: []string{},
+									TypeName:           `Enum`,
+								},
+							},
+						},
+					},
+					OnTypeNames: [][]byte{[]byte(`A`), []byte(`B`)},
+				},
+				{
+					Name: []byte(`interfaceField`),
+					Value: &resolve.Object{
+						Fields: []*resolve.Field{
+							{
+								Name:  []byte(`stringField`),
+								Value: &resolve.String{},
+							},
+						},
+					},
+					OnTypeNames: [][]byte{[]byte(`A`), []byte(`B`)},
+				},
+			},
+		},
+		&resolve.Object{
+			Fields: []*resolve.Field{
+				{
+					Name: []byte(`interfaceField`),
+					Value: &resolve.Object{
+						Fields: []*resolve.Field{
+							{
+								Name: []byte(`enumField`),
+								Value: &resolve.Enum{
+									Values:             []string{`a`},
+									InaccessibleValues: []string{},
+									TypeName:           `Enum`,
+								},
+								ParentOnTypeNames: []resolve.ParentOnTypeNames{
+									{
+										Depth: 1,
+										Names: [][]byte{[]byte(`A`)},
+									},
+								},
+							},
+							{
+								Name:  []byte(`stringField`),
+								Value: &resolve.String{},
+								ParentOnTypeNames: []resolve.ParentOnTypeNames{
+									{
+										Depth: 1,
+										Names: [][]byte{[]byte(`A`)},
+									},
+								},
+							},
+						},
+					},
+					OnTypeNames: [][]byte{[]byte(`A`)},
+				},
+				{
+					Name: []byte(`interfaceField`),
+					Value: &resolve.Object{
+						Fields: []*resolve.Field{
+							{
+								Name: []byte(`enumField`),
+								Value: &resolve.Enum{
+									Values:             []string{`a`},
+									InaccessibleValues: []string{},
+									TypeName:           `Enum`,
+								},
+								ParentOnTypeNames: []resolve.ParentOnTypeNames{
+									{
+										Depth: 1,
+										Names: [][]byte{[]byte(`B`)},
+									},
+								},
+							},
+							{
+								Name:  []byte(`stringField`),
+								Value: &resolve.String{},
+								ParentOnTypeNames: []resolve.ParentOnTypeNames{
+									{
+										Depth: 1,
+										Names: [][]byte{[]byte(`B`)},
+									},
+								},
+							},
+						},
+					},
+					OnTypeNames: [][]byte{[]byte(`B`)},
+				},
+			},
+		},
+	))
+
 	t.Run("merge fields at the end of an object reverse", runTest(
 		&resolve.Object{
 			Fields: []*resolve.Field{
diff --git a/v2/pkg/engine/resolve/node_enum.go b/v2/pkg/engine/resolve/node_enum.go
index 9843fd6ee2..926a6e0c3f 100644
--- a/v2/pkg/engine/resolve/node_enum.go
+++ b/v2/pkg/engine/resolve/node_enum.go
@@ -17,9 +17,12 @@ func (_ *Enum) NodeKind() NodeKind {
 
 func (e *Enum) Copy() Node {
 	return &Enum{
-		Path:     e.Path,
-		Nullable: e.Nullable,
-		Export:   e.Export,
+		Path:               e.Path,
+		Nullable:           e.Nullable,
+		Export:             e.Export,
+		TypeName:           e.TypeName,
+		Values:             e.Values,
+		InaccessibleValues: e.InaccessibleValues,
 	}
 }