Add `date` and `timestamp` types for postgres

extras/drift_postgres/lib/postgres.dart

@@ -16,12 +16,24 @@ typedef UuidColumn = Column<UuidValue>;
 typedef IntervalColumn = Column<Duration>;
 typedef JsonColumn = Column<Object>;
 typedef PointColumn = Column<PgPoint>;
+typedef TimestampColumn = Column<PgDateTime>;
+typedef PgDateColumn = Column<PgDate>;
 
 final class PgTypes {
   PgTypes._();
 
   static const CustomSqlType<UuidValue> uuid = UuidType();
   static const CustomSqlType<Duration> interval = IntervalType();
+  static const CustomSqlType<PgDate> date = DateType(
+    PgDataType.date,
+    'date',
+    PgDate.fromDateTime,
+  );
+  static const CustomSqlType<PgDateTime> timestampNoTimezone = DateType(
+    PgDataType.timestampWithoutTimezone,
+    'timestamp without time zone',
+    PgDateTime.new,
+  );
   static const CustomSqlType<Object> json =
       PostgresType(type: PgDataType.json, name: 'json');
   static const CustomSqlType<Object> jsonb =
@@ -29,6 +41,67 @@ final class PgTypes {
   static const CustomSqlType<PgPoint> point = PointType();
 }
 
+/// A wrapper for values with the Postgres `timestamp without timezone` and
+/// `timestamp with timezone` types.
+///
+/// We can't use [DateTime] directly because drift expects to store them as
+/// unix timestamp or text.
+final class PgDateTime implements PgTimeValue {
+  final DateTime dateTime;
+
+  PgDateTime(this.dateTime);
+
+  @override
+  int get hashCode => dateTime.hashCode;
+
+  @override
+  bool operator ==(Object other) {
+    return other is PgDateTime && other.dateTime == dateTime;
+  }
+
+  @override
+  DateTime toDateTime() => dateTime;
+
+  @override
+  String toString() => dateTime.toString();
+}
+
+/// A wrapper for the Postgres `date` type, which stores dates (year, month,
+/// days).
+final class PgDate implements PgTimeValue {
+  final int year, month, day;
+  final DateTime _dateTime;
+
+  PgDate({required this.year, required this.month, required this.day})
+      : _dateTime = DateTime(year, month, day);
+
+  PgDate.fromDateTime(DateTime dateTime)
+      : _dateTime = dateTime,
+        year = dateTime.year,
+        month = dateTime.month,
+        day = dateTime.day;
+
+  @override
+  int get hashCode => Object.hash(year, month, day);
+
+  @override
+  bool operator ==(Object other) {
+    return other is PgDate &&
+        other.year == year &&
+        other.month == month &&
+        other.day == day;
+  }
+
+  @override
+  String toString() =>
+      '${year.toString().padLeft(4, '0')}-${month.toString().padLeft(2, '0')}-${day.toString().padLeft(2, '0')}';
+
+  @override
+  DateTime toDateTime() {
+    return _dateTime;
+  }
+}
+
 /// Calls the `gen_random_uuid` function in postgres.
 Expression<UuidValue> genRandomUuid() {
   return FunctionCallExpression('gen_random_uuid', []);

extras/drift_postgres/lib/src/types.dart

@@ -65,3 +65,32 @@ class IntervalType extends PostgresType<Duration> {
     return "'${dartValue.inMicroseconds} microseconds'::interval";
   }
 }
+
+abstract interface class PgTimeValue {
+  DateTime toDateTime();
+}
+
+class DateType<T extends PgTimeValue> extends PostgresType<T> {
+  final T Function(DateTime) _fromDateTime;
+
+  const DateType(
+    PgDataType type,
+    String name,
+    this._fromDateTime,
+  ) : super(type: type, name: name);
+
+  @override
+  String mapToSqlLiteral(T dartValue) {
+    return "${PostgresType._encoder.convert(dartValue.toDateTime())}::$name";
+  }
+
+  @override
+  Object mapToSqlParameter(T dartValue) {
+    return PgTypedParameter(type, dartValue.toDateTime());
+  }
+
+  @override
+  T read(Object fromSql) {
+    return _fromDateTime(fromSql as DateTime);
+  }
+}

extras/drift_postgres/test/types_test.dart

@@ -49,5 +49,10 @@ void main() {
     group('json', () => testWith(PgTypes.json, {'foo': 'bar'}));
     group('jsonb', () => testWith(PgTypes.jsonb, {'foo': 'bar'}));
     group('point', () => testWith(PgTypes.point, PgPoint(90, -90)));
+    group(
+      'timestamp without timezone',
+      () => testWith(PgTypes.timestampNoTimezone,
+          PgDateTime(DateTime.utc(1996, 7, 8, 10, 0, 0))),
+    );
   });
 }