Add RFC3339NanoFormatter and UnixNanoFormatter (#276)

json_options.go

@@ -59,6 +59,14 @@ func EpochFormatter(key string) TimeFormatter {
 	})
 }
 
+// UnixNanoFormatter encodes the entry time as a single int64 with nanosecond
+// precision under the provided key.
+func UnixNanoFormatter(key string) TimeFormatter {
+	return TimeFormatter(func(t time.Time) Field {
+		return Int64(key, t.UnixNano())
+	})
+}
+
 // RFC3339Formatter encodes the entry time as an RFC3339-formatted string under
 // the provided key.
 func RFC3339Formatter(key string) TimeFormatter {
@@ -67,6 +75,14 @@ func RFC3339Formatter(key string) TimeFormatter {
 	})
 }
 
+// RFC3339NanoFormatter encodes the entry time as an RFC3339-formatted string
+// with nanosecond precision under the provided key.
+func RFC3339NanoFormatter(key string) TimeFormatter {
+	return TimeFormatter(func(t time.Time) Field {
+		return String(key, t.Format(time.RFC3339Nano))
+	})
+}
+
 // NoTime drops the entry time altogether. It's often useful in testing, since
 // it removes the need to stub time.Now.
 func NoTime() TimeFormatter {

json_options_test.go

@@ -22,6 +22,7 @@ package zap
 
 import (
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -60,6 +61,23 @@ func TestTimeFormatters(t *testing.T) {
 	}
 }
 
+func TestNanoTimeFormatters(t *testing.T) {
+	testtime := time.Date(2017, time.February, 4, 18, 48, 2, 300537459, time.UTC)
+
+	tests := []struct {
+		name      string
+		formatter TimeFormatter
+		expected  Field
+	}{
+		{"UnixNanoFormatter", UnixNanoFormatter("the-time"), Int64("the-time", 1486234082300537459)},
+		{"RFC3339Nano", RFC3339NanoFormatter("ts"), String("ts", "2017-02-04T18:48:02.300537459Z")},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(t, tt.expected, tt.formatter(testtime), "Unexpected output from TimeFormatter %s.", tt.name)
+	}
+}
+
 func TestLevelFormatters(t *testing.T) {
 	const lvl = InfoLevel
 	tests := []struct {