From c15ac5010d38d6ac483fa22275c08e8790c45951 Mon Sep 17 00:00:00 2001
From: Kostiantyn Masliuk <1pkg@protonmail.com>
Date: Mon, 5 Apr 2021 15:33:00 +0200
Subject: [PATCH] use type for embedded fields sorting

---
 fmtio/ast.go         | 23 ++++++++++++++++-------
 fmtio/ast_test.go    | 10 ++++++++++
 walkers/wast_test.go |  8 ++++----
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/fmtio/ast.go b/fmtio/ast.go
index a9f892d..5a0dbda 100644
--- a/fmtio/ast.go
+++ b/fmtio/ast.go
@@ -119,17 +119,18 @@ func fpadfilter(ts *ast.TypeSpec, st gopium.Struct) error {
 }
 
 // shuffle helps to sort fields list
-// for ast type spec accordingly to result struct,
-//
-// note shuffle works properly on structs with
-// one or less embedded fields
+// for ast type spec accordingly to result struct
 func shuffle(ts *ast.TypeSpec, st gopium.Struct) error {
 	// collect fields indexes
 	tts := ts.Type.(*ast.StructType)
 	fields := make(map[string]int, len(st.Fields))
-	// in case struct have two or more embedded fields
-	// this solution will not work as expected
+	// in case of embedded fields
+	// use types to uniquely discern them
 	for i, f := range st.Fields {
+		if f.Name == "" {
+			fields[f.Type] = i
+			continue
+		}
 		fields[f.Name] = i
 	}
 	// shuffle fields list
@@ -138,13 +139,21 @@ func shuffle(ts *ast.TypeSpec, st gopium.Struct) error {
 		// for flat structure non embedded
 		// ast's i-th and j-th fields
 		// in case fields are embedded
-		// use empty name by default
+		// use type instead if possible
 		var ni, nj string
 		if fni := tts.Fields.List[i]; len(fni.Names) == 1 {
 			ni = fni.Names[0].Name
+		} else if len(fni.Names) == 0 {
+			if it, ok := fni.Type.(*ast.Ident); ok {
+				ni = it.Name
+			}
 		}
 		if fnj := tts.Fields.List[j]; len(fnj.Names) == 1 {
 			nj = fnj.Names[0].Name
+		} else if len(fnj.Names) == 0 {
+			if it, ok := fnj.Type.(*ast.Ident); ok {
+				nj = it.Name
+			}
 		}
 		// prepare comparison indexes
 		// and search for them in resulted structure
diff --git a/fmtio/ast_test.go b/fmtio/ast_test.go
index 5cd42b6..50e390b 100644
--- a/fmtio/ast_test.go
+++ b/fmtio/ast_test.go
@@ -114,6 +114,11 @@ func TestAst(t *testing.T) {
 									Value: "embedded",
 								},
 							},
+							{
+								Type: &ast.Ident{
+									Name: "int64",
+								},
+							},
 						},
 					},
 				},
@@ -144,6 +149,10 @@ func TestAst(t *testing.T) {
 						Name: "test-5",
 						Type: "int64",
 					},
+					{
+						Type:     "int64",
+						Embedded: true,
+					},
 					{
 						Type:     "float32",
 						Embedded: true,
@@ -158,6 +167,7 @@ test struct {
 	test-4 int64
 	test-5 int64// random
 	// random
+	int64
 	float32 embedded
 }
 `),
diff --git a/walkers/wast_test.go b/walkers/wast_test.go
index 67f1bb3..497c51b 100644
--- a/walkers/wast_test.go
+++ b/walkers/wast_test.go
@@ -243,10 +243,10 @@ type ze interface {
 }
 
 type Zeze struct {
-	ze
-	D
 	AZ
+	D
 	AWA D
+	ze
 }
 
 // test comment
@@ -332,10 +332,10 @@ type ze interface {
 }
 
 type Zeze struct {
-	ze
-	D
 	AZ
+	D
 	AWA D
+	ze
 }
 
 // test comment