loader/syncer: fix bug in #355 (#381)

* fix situations when there is extra msg in error.Error

* add deal for zap.Error and add UT

pkg/log/log.go

@@ -16,7 +16,9 @@ package log
 import (
 	"context"
 	"fmt"
+	"strings"
 
+	"github.com/pingcap/errors"
 	pclog "github.com/pingcap/log"
 	"github.com/pingcap/tidb/util/logutil"
 	"go.uber.org/zap"
@@ -76,8 +78,16 @@ func (l Logger) WithFields(fields ...zap.Field) Logger {
 // ErrorFilterContextCanceled wraps Logger.Error() and will filter error log when error is context.Canceled
 func (l Logger) ErrorFilterContextCanceled(msg string, fields ...zap.Field) {
 	for _, field := range fields {
-		if field.Key == "error" && field.String == context.Canceled.Error() {
-			return
+		switch field.Type {
+		case zapcore.StringType:
+			if field.Key == "error" && strings.Contains(field.String, context.Canceled.Error()) {
+				return
+			}
+		case zapcore.ErrorType:
+			err, ok := field.Interface.(error)
+			if ok && errors.Cause(err) == context.Canceled {
+				return
+			}
 		}
 	}
 	l.Logger.Error(msg, fields...)

pkg/log/log_test.go

@@ -0,0 +1,67 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package log
+
+import (
+	"context"
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+
+	. "github.com/pingcap/check"
+	"github.com/pingcap/errors"
+)
+
+func TestLog(t *testing.T) {
+	TestingT(t)
+}
+
+type testLogSuite struct{}
+
+var _ = Suite(&testLogSuite{})
+
+func (s *testLogSuite) TestTestLogger(c *C) {
+	logger, buffer := makeTestLogger()
+	logger.Warn("the message", zap.Int("number", 123456), zap.Ints("array", []int{7, 8, 9}))
+	c.Assert(
+		buffer.Stripped(), Equals,
+		`{"$lvl":"WARN","$msg":"the message","number":123456,"array":[7,8,9]}`,
+	)
+	buffer.Reset()
+	logger.ErrorFilterContextCanceled("the message", zap.Int("number", 123456),
+		zap.Ints("array", []int{7, 8, 9}), zap.Error(context.Canceled))
+	c.Assert(buffer.Stripped(), Equals, "")
+	buffer.Reset()
+	logger.ErrorFilterContextCanceled("the message", zap.Int("number", 123456),
+		zap.Ints("array", []int{7, 8, 9}), ShortError(errors.Annotate(context.Canceled, "extra info")))
+	c.Assert(buffer.Stripped(), Equals, "")
+}
+
+// makeTestLogger creates a Logger instance which produces JSON logs.
+func makeTestLogger() (Logger, *zaptest.Buffer) {
+	buffer := new(zaptest.Buffer)
+	logger := zap.New(zapcore.NewCore(
+		zapcore.NewJSONEncoder(zapcore.EncoderConfig{
+			LevelKey:       "$lvl",
+			MessageKey:     "$msg",
+			EncodeLevel:    zapcore.CapitalLevelEncoder,
+			EncodeDuration: zapcore.StringDurationEncoder,
+		}),
+		buffer,
+		zap.DebugLevel,
+	))
+	return Logger{Logger: logger}, buffer
+}