add now and nil test to marshal for timestamp

pkg/timestamp/timestamp.go

@@ -2,6 +2,7 @@ package timestamp
 
 import (
 	_ "embed"
+	"time"
 
 	"golang.org/x/exp/constraints"
 )
@@ -18,6 +19,8 @@ type T struct{ N uint64 }
 
 func New[V constraints.Integer](n V) *T { return &T{uint64(n)} }
 
+func Now() *T { return New(time.Now().Unix()) }
+
 func (n *T) Uint64() uint64 { return n.N }
 func (n *T) Int64() int64   { return int64(n.N) }
 func (n *T) Uint16() uint16 { return uint16(n.N) }
@@ -33,7 +36,11 @@ var powers = []*T{
 const zero = '0'
 const nine = '9'
 
-func (n *T) Marshal(dst []byte) (b []byte) {
+func (n *T) Marshal(dst []byte) (b []byte, err error) {
+	if n == nil {
+		err = errorf.E("cannot marshal nil timestamp")
+		return
+	}
 	nn := n.N
 	b = dst
 	if n.N == 0 {

pkg/timestamp/timestamp_test.go

@@ -15,7 +15,9 @@ func TestMarshalUnmarshal(t *testing.T) {
 	var err error
 	for _ = range 10000000 {
 		n = New(uint64(frand.Intn(math.MaxInt64)))
-		b = n.Marshal(b)
+		if b, err = n.Marshal(b); chk.E(err) {
+			t.Fatal(err)
+		}
 		m := New(0)
 		if rem, err = m.Unmarshal(b); chk.E(err) {
 			t.Fatal(err)
@@ -42,7 +44,7 @@ func BenchmarkByteStringToInt64(bb *testing.B) {
 		bb.ReportAllocs()
 		for i = 0; i < bb.N; i++ {
 			n := testInts[i%10000]
-			b = n.Marshal(b)
+			b, _ = n.Marshal(b)
 			b = b[:0]
 		}
 	})
@@ -60,7 +62,7 @@ func BenchmarkByteStringToInt64(bb *testing.B) {
 		m := New(0)
 		for i = 0; i < bb.N; i++ {
 			n := testInts[i%10000]
-			b = m.Marshal(b)
+			b, _ = m.Marshal(b)
 			_, _ = n.Unmarshal(b)
 			b = b[:0]
 		}