fix: ParseJsonBody error when request has []byte field zeromicro#4450

--bug=4450

core/mapping/unmarshaler.go

@@ -2,6 +2,7 @@ package mapping
 
 import (
 	"encoding"
+	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -737,7 +738,15 @@ func (u *Unmarshaler) processFieldTextUnmarshaler(fieldType reflect.Type, value
 			return true, tval.UnmarshalText(mv)
 		}
 	}
-
+	//[]byte
+	if fieldType.Kind() == reflect.Slice && fieldType.Elem().Kind() == reflect.Uint8 {
+		b, err := base64.StdEncoding.DecodeString(mapValue.(string))
+		if err != nil {
+			return false, err
+		}
+		value.SetBytes(b)
+		return true, nil
+	}
 	return false, nil
 }
 

rest/httpx/requests_test.go

@@ -2,6 +2,7 @@ package httpx
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
 	"net/http"
 	"net/http/httptest"
@@ -350,6 +351,25 @@ func TestParseJsonBody(t *testing.T) {
 		assert.Equal(t, "apple", v[0].Name)
 		assert.Equal(t, 18, v[0].Age)
 	})
+	t.Run("bytes field", func(t *testing.T) {
+		type v struct {
+			Signature []byte `json:"signature,optional"`
+		}
+		v1 := v{
+			Signature: []byte{0x01, 0xff, 0x00},
+		}
+		body, _ := json.Marshal(v1)
+		t.Logf("body:%s", string(body))
+		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(string(body)))
+		r.Header.Set(ContentType, header.JsonContentType)
+		var v2 v
+		err := ParseJsonBody(r, &v2)
+		if assert.NoError(t, err) {
+			assert.Greater(t, len(v2.Signature), 0)
+		}
+		t.Logf("%x", v2.Signature)
+		assert.EqualValues(t, v1.Signature, v2.Signature)
+	})
 }
 
 func TestParseRequired(t *testing.T) {