fix golint issues in formatters

formatter.go

@@ -2,7 +2,7 @@ package logrus
 
 import "time"
 
-const DefaultTimestampFormat = time.RFC3339
+const defaultTimestampFormat = time.RFC3339
 
 // The Formatter interface is used to implement a custom Formatter. It takes an
 // `Entry`. It exposes all the fields, including the default ones:

json_formatter.go

@@ -6,8 +6,11 @@ import (
 )
 
 type fieldKey string
+
+// FieldMap allows customization of the key names for default fields.
 type FieldMap map[fieldKey]string
 
+// Default key names for the default fields
 const (
 	FieldKeyMsg   = "msg"
 	FieldKeyLevel = "level"
@@ -22,6 +25,7 @@ func (f FieldMap) resolve(key fieldKey) string {
 	return string(key)
 }
 
+// JSONFormatter formats logs into parsable json
 type JSONFormatter struct {
 	// TimestampFormat sets the format used for marshaling timestamps.
 	TimestampFormat string
@@ -29,7 +33,7 @@ type JSONFormatter struct {
 	// DisableTimestamp allows disabling automatic timestamps in output
 	DisableTimestamp bool
 
-	// FieldMap allows users to customize the names of keys for various fields.
+	// FieldMap allows users to customize the names of keys for default fields.
 	// As an example:
 	// formatter := &JSONFormatter{
 	//   	FieldMap: FieldMap{
@@ -41,6 +45,7 @@ type JSONFormatter struct {
 	FieldMap FieldMap
 }
 
+// Format renders a single log entry
 func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 	data := make(Fields, len(entry.Data)+3)
 	for k, v := range entry.Data {
@@ -57,7 +62,7 @@ func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 
 	timestampFormat := f.TimestampFormat
 	if timestampFormat == "" {
-		timestampFormat = DefaultTimestampFormat
+		timestampFormat = defaultTimestampFormat
 	}
 
 	if !f.DisableTimestamp {

text_formatter.go

@@ -26,6 +26,7 @@ func init() {
 	baseTimestamp = time.Now()
 }
 
+// TextFormatter formats logs into text
 type TextFormatter struct {
 	// Set to true to bypass checking for a TTY before outputting colors.
 	ForceColors bool
@@ -64,6 +65,7 @@ func (f *TextFormatter) init(entry *Entry) {
 	}
 }
 
+// Format renders a single log entry
 func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 	var b *bytes.Buffer
 	keys := make([]string, 0, len(entry.Data))
@@ -88,7 +90,7 @@ func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 
 	timestampFormat := f.TimestampFormat
 	if timestampFormat == "" {
-		timestampFormat = DefaultTimestampFormat
+		timestampFormat = defaultTimestampFormat
 	}
 	if isColored {
 		f.printColored(b, entry, keys, timestampFormat)