Add time (#7)

encode.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"time"
 )
 
 // Encoder writes BSON values to an output stream.
@@ -55,6 +56,11 @@ func (e *Encoder) marshal(v any) error {
 		e.buf.Write([]byte(v))
 		e.buf.WriteByte(0)
 
+	case time.Time:
+		var b [8]byte
+		binary.LittleEndian.PutUint64(b[:], uint64(v.UnixMilli()))
+		e.buf.Write(b[:])
+
 	case int32:
 		var b [4]byte
 		binary.LittleEndian.PutUint32(b[:], uint32(v))

encode_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"math"
 	"testing"
+	"time"
 )
 
 func TestEncode(t *testing.T) {
@@ -92,3 +93,27 @@ func TestEncodeNumbers(t *testing.T) {
 	wantBytes(t, buf.Bytes(), "713d0ad7a3104540")
 	buf.Reset()
 }
+
+func TestEncodeTime(t *testing.T) {
+	var err error
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+
+	var ts time.Time
+	err = enc.Encode(ts)
+	mustOk(t, err)
+	wantBytes(t, buf.Bytes(), "0028d3ed7cc7ffff")
+	buf.Reset()
+
+	ts = time.Unix(0, 0)
+	err = enc.Encode(ts)
+	mustOk(t, err)
+	wantBytes(t, buf.Bytes(), "0000000000000000")
+	buf.Reset()
+
+	ts = time.Date(2023, 8, 17, 10, 20, 30, 0, time.UTC)
+	err = enc.Encode(ts)
+	mustOk(t, err)
+	wantBytes(t, buf.Bytes(), "b0cd02038a010000")
+	buf.Reset()
+}