Add tests for error in InfoS

Author: tahsinrahman

klog.go

@@ -802,7 +802,7 @@ func kvListFormat(b *bytes.Buffer, keysAndValues ...interface{}) {
 		b.WriteByte(' ')
 
 		switch v.(type) {
-		case string:
+		case string, error:
 			b.WriteString(fmt.Sprintf("%s=%q", k, v))
 		default:
 			if _, ok := v.(fmt.Stringer); ok {

klog_test.go

@@ -18,6 +18,7 @@ package klog
 
 import (
 	"bytes"
+	"errors"
 	"flag"
 	"fmt"
 	"io/ioutil"
@@ -792,6 +793,16 @@ func TestInfoS(t *testing.T) {
 			format:     "I0102 15:04:05.067890    1234 klog_test.go:%d] \"test\" replicaNum=20\n",
 			keysValues: []interface{}{"replicaNum", 20},
 		},
+		{
+			msg:        "test",
+			format:     "I0102 15:04:05.067890    1234 klog_test.go:%d] \"test\" err=\"test error\"\n",
+			keysValues: []interface{}{"err", errors.New("test error")},
+		},
+		{
+			msg:        "test",
+			format:     "I0102 15:04:05.067890    1234 klog_test.go:%d] \"test\" err=\"test error\"\n",
+			keysValues: []interface{}{"err", errors.New("test error")},
+		},
 	}
 
 	for _, data := range testDataInfo {