Fix unexported fields

Author: roman.atachiants@careem.com

scanner.go

@@ -131,18 +131,19 @@ func scanType(t reflect.Type) (Codec, error) {
 
 	case reflect.Struct:
 		s := scanStruct(t)
-		v := make(reflectStructCodec, len(s.fields))
+		v := make(reflectStructCodec, 0, len(s.fields))
 		for _, i := range s.fields {
 			field := t.Field(i)
 			codec, err := scanType(field.Type)
 			if err != nil {
 				return nil, err
 			}
 
-			v[i] = fieldCodec{
+			// Append since unexported fields are skipped
+			v = append(v, fieldCodec{
 				Index: i,
 				Codec: codec,
-			}
+			})
 		}
 
 		return &v, nil

scanner_test.go

@@ -6,6 +6,7 @@ package binary
 import (
 	"bytes"
 	"reflect"
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -28,8 +29,6 @@ func TestScanner(t *testing.T) {
 	e := NewEncoder(&b)
 	err = codec.EncodeTo(e, reflect.Indirect(reflect.ValueOf(s0v)))
 	assert.NoError(t, err)
-
-	//e.Flush()
 	assert.Equal(t, s0b, b.Bytes())
 }
 
@@ -40,3 +39,22 @@ func TestScanner_Custom(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotNil(t, codec)
 }
+
+func TestScannerComposed(t *testing.T) {
+	codec, err := scan(reflect.TypeOf(Partition{}))
+	assert.NoError(t, err)
+	assert.NotNil(t, codec)
+}
+
+type Partition struct {
+	Strings
+	Filters map[uint32][]uint64
+}
+
+type Strings struct {
+	lock sync.Mutex `binary:"-"`
+	Key  string
+	Fill []uint64
+	Hash []uint32
+	Data map[uint64][]byte
+}