Make sure timestamp is formatted as a float

json_codec_test.go

@@ -36,3 +36,10 @@ func (s *JsonCodecSuite) TestJsonCodec(c *C) {
 		c.Check(string(m), Matches, fmt.Sprintf(`{.*"%s":.*}`, f))
 	}
 }
+
+func (s *JsonCodecSuite) TestTimestampIsFormattedAsFloat(c *C) {
+	r := NewRecord("source", LOG_INFO, "Hello world", nil)
+	m, err := s.EncodeRecord(r)
+	c.Assert(err, IsNil)
+	c.Assert(string(m), Matches, `.*"timestamp":\d{10}\.\d{9},.*`)
+}

json_prettifier.go

@@ -76,7 +76,7 @@ func encodeLevel(level LogLevel) string {
 	return fmt.Sprintf("%s ", strings.ToUpper(level.String()))
 }
 
-func encodeTimestamp(t float64) string {
+func encodeTimestamp(t RecordTimestamp) string {
 	ut := time.Unix(int64(t), 0)
 	return fmt.Sprintf("%s ", ut.Format("2006-01-02 15:04:05"))
 }

record.go

@@ -1,14 +1,21 @@
 package steno
 
 import (
+	"fmt"
 	"os"
 	"runtime"
 	"strings"
 	"time"
 )
 
+type RecordTimestamp float64
+
+func (t RecordTimestamp) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf("%.9f", t)), nil
+}
+
 type Record struct {
-	Timestamp float64                `json:"timestamp"`
+	Timestamp RecordTimestamp        `json:"timestamp"`
 	Pid       int                    `json:"process_id"`
 	Source    string                 `json:"source"`
 	Level     LogLevel               `json:"log_level"`
@@ -27,7 +34,7 @@ func init() {
 
 func NewRecord(s string, l LogLevel, m string, d map[string]interface{}) *Record {
 	r := &Record{
-		Timestamp: float64(time.Now().UnixNano()) / 1000000000,
+		Timestamp: RecordTimestamp(time.Now().UnixNano()) / 1000000000,
 		Pid:       pid,
 		Source:    s,
 		Level:     l,