Add tests for null sorting on asc/desc factories

docs/pages/docs/Examples/existing_databases.md

@@ -46,7 +46,6 @@ import 'package:drift/drift.dart';
 import 'package:flutter/services.dart' show rootBundle;
 import 'package:path/path.dart' as p;
 
-
 LazyDatabase _openConnection() {
   return LazyDatabase(() async {
     // put the database file, called db.sqlite here, into the documents folder

drift/lib/src/runtime/query_builder/components/order_by.dart

@@ -53,7 +53,7 @@ class OrderingTerm extends Component {
 
   /// Creates an ordering term that sorts for ascending values
   /// of [expression] and the [nulls].
-  factory OrderingTerm.asc(Expression expression, [NullsOrder? nulls]) {
+  factory OrderingTerm.asc(Expression expression, {NullsOrder? nulls}) {
     return OrderingTerm(
       expression: expression,
       mode: OrderingMode.asc,
@@ -63,7 +63,7 @@ class OrderingTerm extends Component {
 
   /// Creates an ordering term that sorts for descending values
   /// of [expression] and the [nulls].
-  factory OrderingTerm.desc(Expression expression, [NullsOrder? nulls]) {
+  factory OrderingTerm.desc(Expression expression, {NullsOrder? nulls}) {
     return OrderingTerm(
       expression: expression,
       mode: OrderingMode.desc,

drift/test/database/statements/order_by_test.dart

@@ -75,4 +75,14 @@ void main() {
       argThat(isEmpty),
     ));
   });
+
+  test('works with helper factories', () {
+    final table = db.users;
+
+    expect(OrderingTerm.asc(table.id), generates('id ASC'));
+    expect(OrderingTerm.asc(table.id, nulls: NullsOrder.last),
+        generates('id ASC NULLS LAST'));
+    expect(OrderingTerm.desc(table.id, nulls: NullsOrder.first),
+        generates('id DESC NULLS FIRST'));
+  });
 }