fix(proto): DateTime/DateTime64 with '1970-01-01 00:00:00 UTC'

proto/datetime.go

@@ -15,9 +15,6 @@ func ToDateTime(t time.Time) DateTime {
 
 // Time returns DateTime as time.Time.
 func (d DateTime) Time() time.Time {
-	if d == 0 {
-		return time.Time{}
-	}
 	// https://clickhouse.com/docs/en/sql-reference/data-types/datetime/#usage-remarks
 	// ClickHouse stores UTC timestamps that are timezone-agnostic.
 	return time.Unix(int64(d), 0)

proto/datetime64.go

@@ -57,9 +57,6 @@ func ToDateTime64(t time.Time, p Precision) DateTime64 {
 
 // Time returns DateTime64 as time.Time.
 func (d DateTime64) Time(p Precision) time.Time {
-	if d == 0 {
-		return time.Time{}
-	}
 	nsec := int64(d) * p.Scale()
 	return time.Unix(nsec/1e9, nsec%1e9)
 }

proto/datetime64_test.go

@@ -18,7 +18,7 @@ func TestDateTime64_Time(t *testing.T) {
 	} {
 		t.Run(p.Duration().String(), func(t *testing.T) {
 			for _, v := range []time.Time{
-				{}, // zero time
+				time.Unix(0, 0).UTC(), // zero time
 				time.Unix(1546290000, 0).UTC(),
 			} {
 				d := ToDateTime64(v, p)
@@ -28,6 +28,21 @@ func TestDateTime64_Time(t *testing.T) {
 				assert.True(t, p.Valid())
 			}
 		})
+
+		t.Run("Zero_"+p.Duration().String(), func(t *testing.T) {
+			t1 := time.Time{}
+			t2 := time.Unix(0, 0).UTC()
+			d1 := ToDateTime64(t1, p)
+			d2 := ToDateTime64(t2, p)
+			vt1 := d1.Time(p)
+			vt2 := d2.Time(p)
+
+			assert.True(t, t1.IsZero())
+			assert.False(t, t2.IsZero())
+			assert.Equal(t, d1, d2)
+			assert.Equal(t, vt1.Unix(), int64(0))
+			assert.Equal(t, vt2.Unix(), int64(0))
+		})
 	}
 	t.Run("Duration", func(t *testing.T) {
 		assert.Equal(t, time.Second, PrecisionSecond.Duration(), "sec")

proto/datetime_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestDateTime_Time(t *testing.T) {
+func TestDateTime_ToDateTime(t *testing.T) {
 	t.Run("Ok", func(t *testing.T) {
 		v := time.Unix(1546290000, 0).UTC()
 		d := ToDateTime(v)
@@ -19,3 +19,22 @@ func TestDateTime_Time(t *testing.T) {
 		assert.Equal(t, int32(0), int32(d))
 	})
 }
+
+func TestDateTime_Time(t *testing.T) {
+	t.Run("OK", func(t *testing.T) {
+		d := DateTime(1546290000)
+		assert.Equal(t, d.Time().Unix(), int64(1546290000))
+	})
+
+	t.Run("Zero", func(t *testing.T) {
+		d := DateTime(0)
+		assert.Equal(t, d.Time().Unix(), int64(0))
+	})
+
+	t.Run("IsZero", func(t *testing.T) {
+		d1 := DateTime(0)
+		d2 := time.Time{}
+		assert.Equal(t, d1.Time().IsZero(), false)
+		assert.Equal(t, d2.IsZero(), true)
+	})
+}