Add tests

drift/test/database/expressions/datetime_expression_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 import '../../test_utils/test_utils.dart';
 
-typedef _Extractor = Expression<int?> Function(Expression<DateTime?> d);
+typedef _Extractor = Expression Function(Expression<DateTime?> d);
 
 void main() {
   const column =
@@ -17,15 +17,14 @@ void main() {
       (d) => d.hour: "CAST(strftime('%H', val, 'unixepoch') AS INTEGER)",
       (d) => d.minute: "CAST(strftime('%M', val, 'unixepoch') AS INTEGER)",
       (d) => d.second: "CAST(strftime('%S', val, 'unixepoch') AS INTEGER)",
+      (d) => d.date: "DATE(val, 'unixepoch')",
+      (d) => d.datetime: "DATETIME(val, 'unixepoch')",
+      (d) => d.time: "TIME(val, 'unixepoch')",
     };
 
     expectedResults.forEach((key, value) {
       test('should extract field', () {
-        final ctx = GenerationContext(SqlTypeSystem.defaultInstance, null);
-        key(column).writeInto(ctx);
-
-        expect(ctx.sql, value);
-
+        expect(key(column), generates(value));
         expectEquals(key(column), key(column));
       });
     });

drift/test/database/expressions/expressions_integration_test.dart

@@ -37,11 +37,19 @@ void main() {
         const Duration(days: 1).inSeconds);
   });
 
-  test('datetime.date format', () {
-    final expr = Variable.withDateTime(DateTime(2020, 09, 04, 8, 55));
-    final asDate = expr.date;
+  test('extracting values from datetime', () {
+    final expr = Variable.withDateTime(DateTime.utc(2020, 09, 04, 8, 55));
 
-    expect(eval(asDate), completion('2020-09-04'));
+    expect(eval(expr.year), completion(2020));
+    expect(eval(expr.month), completion(9));
+    expect(eval(expr.day), completion(4));
+    expect(eval(expr.hour), completion(8));
+    expect(eval(expr.minute), completion(55));
+    expect(eval(expr.second), completion(0));
+
+    expect(eval(expr.date), completion('2020-09-04'));
+    expect(eval(expr.time), completion('08:55:00'));
+    expect(eval(expr.datetime), completion('2020-09-04 08:55:00'));
   });
 
   test('rowid', () {

drift/test/test_utils/matchers.dart

@@ -13,9 +13,8 @@ void expectNotEquals(dynamic a, dynamic expected) {
 
 /// Matcher for [Component]-subclasses. Expect that a component generates the
 /// matching [sql] and, optionally, the matching [variables].
-Matcher generates(dynamic sql, [dynamic variables]) {
-  final variablesMatcher = variables != null ? wrapMatcher(variables) : isEmpty;
-  return _GeneratesSqlMatcher(wrapMatcher(sql), variablesMatcher);
+Matcher generates(dynamic sql, [dynamic variables = isEmpty]) {
+  return _GeneratesSqlMatcher(wrapMatcher(sql), wrapMatcher(variables));
 }
 
 class _GeneratesSqlMatcher extends Matcher {