Merge pull request #222 from ydb-platform/json-unmarshaler

Json unmarshaler

Author: asmyasnikov

CHANGELOG.md

@@ -1,4 +1,5 @@
-* Reimplement sugar.DSN with net/url
+* Supported `json.Unmarshaler` type for scanning row to values 
+* Reimplement `sugar.DSN` with `net/url`
 
 ## v3.21.0
 * Fixed gtrace tool generation code style bug with leading spaces

internal/table/scanner/scanner.go

@@ -3,6 +3,7 @@ package scanner
 import (
 	"bytes"
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"io"
 	"math"
@@ -717,6 +718,7 @@ func (s *scanner) trySetByteArray(v interface{}, optional bool, def bool) bool {
 	return true
 }
 
+// nolint: gocyclo
 func (s *scanner) scanRequired(value interface{}) {
 	switch v := value.(type) {
 	case *bool:
@@ -771,6 +773,19 @@ func (s *scanner) scanRequired(value interface{}) {
 		if err != nil {
 			_ = s.errorf(0, "sql.Scanner error: %w", err)
 		}
+	case json.Unmarshaler:
+		var err error
+		switch s.getType() {
+		case types.TypeJSON:
+			err = v.UnmarshalJSON(s.converter.JSON())
+		case types.TypeJSONDocument:
+			err = v.UnmarshalJSON(s.converter.JSONDocument())
+		default:
+			_ = s.errorf(0, "ydb required type %T not unsupported for applying to json.Unmarshaler", s.getType())
+		}
+		if err != nil {
+			_ = s.errorf(0, "json.Unmarshaler error: %w", err)
+		}
 	default:
 		ok := s.trySetByteArray(v, false, false)
 		if !ok {
@@ -949,6 +964,20 @@ func (s *scanner) scanOptional(value interface{}, defaultValueForOptional bool)
 		if err != nil {
 			_ = s.errorf(0, "sql.Scanner error: %w", err)
 		}
+	case json.Unmarshaler:
+		s.unwrap()
+		var err error
+		switch s.getType() {
+		case types.TypeJSON:
+			err = v.UnmarshalJSON(s.converter.JSON())
+		case types.TypeJSONDocument:
+			err = v.UnmarshalJSON(s.converter.JSONDocument())
+		default:
+			_ = s.errorf(0, "ydb optional type %T not unsupported for applying to json.Unmarshaler", s.getType())
+		}
+		if err != nil {
+			_ = s.errorf(0, "json.Unmarshaler error: %w", err)
+		}
 	default:
 		s.unwrap()
 		ok := s.trySetByteArray(v, true, false)
@@ -1013,6 +1042,11 @@ func (s *scanner) setDefaultValue(dst interface{}) {
 		if err != nil {
 			_ = s.errorf(0, "ydb.Scanner error: %w", err)
 		}
+	case json.Unmarshaler:
+		err := v.UnmarshalJSON(nil)
+		if err != nil {
+			_ = s.errorf(0, "json.Unmarshaler error: %w", err)
+		}
 	default:
 		ok := s.trySetByteArray(v, false, true)
 		if !ok {

internal/table/scanner/scanner_test.go

@@ -2,6 +2,7 @@ package scanner
 
 import (
 	"encoding/binary"
+	"encoding/json"
 	"math"
 	"strconv"
 	"testing"
@@ -595,3 +596,112 @@ func TestScanNamed(t *testing.T) {
 		})
 	}
 }
+
+type jsonUnmarshaller struct {
+	bytes []byte
+}
+
+func (json *jsonUnmarshaller) UnmarshalJSON(bytes []byte) error {
+	json.bytes = bytes
+	return nil
+}
+
+var _ json.Unmarshaler = &jsonUnmarshaller{}
+
+func TestScanToJsonUnmarshaller(t *testing.T) {
+	s := initScanner()
+	for _, test := range []struct {
+		name    string
+		count   int
+		columns []*column
+		values  []indexed.RequiredOrOptional
+	}{
+		{
+			name:  "<optional JSONDocument, required JSON> to json.Unmarshaller",
+			count: 2,
+			columns: []*column{{
+				name:     "jsondocument",
+				typeID:   Ydb.Type_JSON_DOCUMENT,
+				optional: true,
+			}, {
+				name:   "json",
+				typeID: Ydb.Type_JSON,
+			}},
+			values: []indexed.RequiredOrOptional{
+				new(jsonUnmarshaller),
+				new(jsonUnmarshaller),
+			},
+		}, {
+			name:  "<required JSONDocument, optional JSON> to json.Unmarshaller",
+			count: 2,
+			columns: []*column{{
+				name:   "jsondocument",
+				typeID: Ydb.Type_JSON_DOCUMENT,
+			}, {
+				name:     "json",
+				typeID:   Ydb.Type_JSON,
+				optional: true,
+			}},
+			values: []indexed.RequiredOrOptional{
+				new(jsonUnmarshaller),
+				new(jsonUnmarshaller),
+			},
+		}, {
+			name:  "<optional JSONDocument, optional JSON> to json.Unmarshaller",
+			count: 2,
+			columns: []*column{{
+				name:     "jsondocument",
+				typeID:   Ydb.Type_JSON_DOCUMENT,
+				optional: true,
+			}, {
+				name:     "json",
+				typeID:   Ydb.Type_JSON,
+				optional: true,
+			}},
+			values: []indexed.RequiredOrOptional{
+				new(jsonUnmarshaller),
+				new(jsonUnmarshaller),
+			},
+		}, {
+			name:  "<required JSONDocument, required JSON> to json.Unmarshaller",
+			count: 2,
+			columns: []*column{{
+				name:   "jsondocument",
+				typeID: Ydb.Type_JSON_DOCUMENT,
+			}, {
+				name:   "json",
+				typeID: Ydb.Type_JSON,
+			}},
+			values: []indexed.RequiredOrOptional{
+				new(jsonUnmarshaller),
+				new(jsonUnmarshaller),
+			},
+		},
+	} {
+		set, _ := getResultSet(test.count, test.columns)
+		s.reset(set)
+		for s.NextRow() {
+			values := make([]indexed.RequiredOrOptional, 0, len(test.values))
+			for i, col := range test.columns {
+				if col.optional {
+					values = append(
+						values,
+						indexed.Optional(
+							test.values[i],
+						),
+					)
+				} else {
+					values = append(
+						values,
+						indexed.Required(
+							test.values[i],
+						),
+					)
+				}
+			}
+			if err := s.Scan(values...); err != nil {
+				t.Fatalf("test: %s; error: %s", test.name, err)
+			}
+		}
+	}
+}

table/result/indexed/indexed.go

@@ -5,7 +5,7 @@ package indexed
 //
 // This is a proxy type for preparing go1.18 type set constrains such as
 //   type Required interface {
-//     *int8 | *int64 | *string | types.Scanner
+//     *int8 | *int64 | *string | types.Scanner | json.Unmarshaler
 //   }
 type Required interface{}
 
@@ -14,7 +14,7 @@ type Required interface{}
 //
 // This is a proxy type for preparing go1.18 type set constrains such as
 //   type Optional interface {
-//     **int8 | **int64 | **string | types.Scanner
+//     **int8 | **int64 | **string | types.Scanner | json.Unmarshaler
 //   }
 // or alias such as
 //   type Optional *Required

table/result/result.go

@@ -92,7 +92,7 @@ type result interface {
 	//   time.Time
 	//   time.Duration
 	//   ydb.Value
-	// For custom types implement sql.Scanner interface.
+	// For custom types implement sql.Scanner or json.Unmarshaler interface.
 	// For optional types use double pointer construction.
 	// For unknown types use interface types.
 	// Supported scanning byte arrays of various length.