add a NullSnowflake implementation

null_snowflake.go

@@ -0,0 +1,74 @@
+package snowflake
+
+import (
+	"bytes"
+	"database/sql/driver"
+	"encoding/json"
+)
+
+var nullBytes = []byte("null")
+
+// NullSnowflake is a nullable Snowflake
+type NullSnowflake struct {
+	Snowflake Snowflake
+	Valid     bool
+}
+
+// NewNullSnowflake creates a new NullSnowflake
+func NewNullSnowflake(s Snowflake, valid bool) NullSnowflake {
+	return NullSnowflake{
+		Snowflake: s,
+		Valid:     valid,
+	}
+}
+
+// Scan implements sql.Scanner interface
+func (s *NullSnowflake) Scan(value any) error {
+	if value == nil {
+		s.Snowflake, s.Valid = Snowflake(0), false
+		return nil
+	}
+	s.Valid = true
+	return (&s.Snowflake).Scan(value)
+}
+
+// Value implements driver.Valuer interface
+func (s NullSnowflake) Value() (driver.Value, error) {
+	if !s.Valid {
+		return nil, nil
+	}
+	return s.Snowflake.Value()
+}
+
+// ValueOrZero returns the inner value if valid, otherwise zero.
+func (s NullSnowflake) ValueOrZero() Snowflake {
+	if !s.Valid {
+		return Snowflake(0)
+	}
+	return s.Snowflake
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *NullSnowflake) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		s.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &s.Snowflake); err != nil {
+		return err
+	}
+
+	s.Valid = true
+
+	return nil
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s NullSnowflake) MarshalJSON() ([]byte, error) {
+	if !s.Valid {
+		return nullBytes, nil
+	}
+
+	return s.Snowflake.MarshalJSON()
+}