Fix SQL visibility page token deserializer (#4074)

common/persistence/visibility/store/sql/pagination_token.go

@@ -38,7 +38,7 @@ type (
 )
 
 func deserializePageToken(data []byte) (*pageToken, error) {
-	if data == nil {
+	if len(data) == 0 {
 		return nil, nil
 	}
 	var token *pageToken

common/persistence/visibility/store/sql/pagination_token_test.go

@@ -0,0 +1,74 @@
+// The MIT License
+//
+// Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
+//
+// Copyright (c) 2020 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package sql
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSerializePageToken(t *testing.T) {
+	s := assert.New(t)
+
+	token := pageToken{
+		CloseTime: time.Date(2023, 3, 21, 14, 20, 32, 0, time.UTC),
+		StartTime: time.Date(2023, 3, 21, 14, 10, 32, 0, time.UTC),
+		RunID:     "test-run-id",
+	}
+	data, err := serializePageToken(&token)
+	s.NoError(err)
+	s.Equal(
+		[]byte(`{"CloseTime":"2023-03-21T14:20:32Z","StartTime":"2023-03-21T14:10:32Z","RunID":"test-run-id"}`),
+		data,
+	)
+}
+
+func TestDeserializePageToken(t *testing.T) {
+	s := assert.New(t)
+
+	token, err := deserializePageToken(nil)
+	s.NoError(err)
+	s.Nil(token)
+
+	token, err = deserializePageToken([]byte{})
+	s.NoError(err)
+	s.Nil(token)
+
+	token, err = deserializePageToken(
+		[]byte(`{"CloseTime":"2023-03-21T14:20:32Z","StartTime":"2023-03-21T14:10:32Z","RunID":"test-run-id"}`),
+	)
+	s.NoError(err)
+	s.NotNil(token)
+	s.Equal(
+		pageToken{
+			CloseTime: time.Date(2023, 3, 21, 14, 20, 32, 0, time.UTC),
+			StartTime: time.Date(2023, 3, 21, 14, 10, 32, 0, time.UTC),
+			RunID:     "test-run-id",
+		},
+		*token,
+	)
+}