test(database): cover down migration hashing

docs/1-essentials/07-testing.md

@@ -22,7 +22,7 @@ composer phpunit
 
 ## Test-specific discovery locations
 
-Tempest will only discover non-dev namespaces defined in composer.json automatically. That means that `{:hl-keyword:require-dev:}` namespaces aren't discovered automatically. Whenever you need Tempest to discover test-specific locations, you may specify them within the `discoverTestLocations()` method of the provided `IntegrationTest` class. 
+Tempest will only discover non-dev namespaces defined in composer.json automatically. That means that `{:hl-keyword:require-dev:}` namespaces aren't discovered automatically. Whenever you need Tempest to discover test-specific locations, you may specify them within the `discoverTestLocations()` method of the provided `IntegrationTest` class.
 
 On top of that, Tempest _will_ look for files in the `tests/Fixtures` directory and discover them by default. You can override this behavior by providing your own implementation of `discoverTestLocations()`, where you can return an array of `DiscoveryLocation` objects (or nothing).
 
@@ -46,7 +46,7 @@ final class HomeControllerTest extends IntegrationTest
 If you want to test code that interacts with the database, your test class can call the `setupDatabase()` method. This method will create and migrate a clean database for you on the fly.
 
 ```php
-class TodoControllerTest extends IntegrationTest
+final class TodoControllerTest extends IntegrationTest
 {
     protected function setUp(): void
     {
@@ -60,8 +60,6 @@ class TodoControllerTest extends IntegrationTest
 Most likely, you'll want to use a test-specific database connection. You can create a `database.config.php` file anywhere within test-specific discovery locations, and Tempest will use that connection instead of the project's default. For example, you can create a file `tests/Fixtures/database.config.php` like so:
 
 ```php tests/Fixtures/database.config.php
-<?php
-
 use Tempest\Database\Config\SQLiteConfig;
 
 return new SQLiteConfig(
@@ -72,7 +70,7 @@ return new SQLiteConfig(
 By default, no tables will be migrated. You can choose to provide a list of migrations that will be run for every test that calls `setupDatabase()`, or you can run specific migrations on a per-test basis.
 
 ```php
-class TodoControllerTest extends IntegrationTest
+final class TodoControllerTest extends IntegrationTest
 {
     protected function migrateDatabase(): void
     {
@@ -85,7 +83,7 @@ class TodoControllerTest extends IntegrationTest
 ```
 
 ```php
-class TodoControllerTest extends IntegrationTest
+final class TodoControllerTest extends IntegrationTest
 {
     public function test_create_todo(): void
     {

packages/database/src/Migrations/MigrationManager.php

@@ -306,7 +306,7 @@ private function getTableDefinitions(): array
         );
     }
 
-    private function getMigrationHash(MigratesUp $migration): string
+    private function getMigrationHash(MigratesUp|MigratesDown $migration): string
     {
         $sql = '';
 

packages/database/src/Migrations/RunnableMigrations.php

@@ -19,7 +19,7 @@ final class RunnableMigrations implements IteratorAggregate
     public function __construct(
         private array $migrations = [],
     ) {
-        usort($this->migrations, static fn (MigratesUp $a, MigratesUp $b) => strnatcmp($a->name, $b->name));
+        usort($this->migrations, static fn (MigratesUp|MigratesDown $a, MigratesUp|MigratesDown $b) => strnatcmp($a->name, $b->name));
     }
 
     public function getIterator(): Traversable

src/Tempest/Framework/Testing/IntegrationTest.php

@@ -166,21 +166,24 @@ protected function setupBaseRequest(): self
     protected function setupDatabase(): self
     {
         $migrationManager = $this->container->get(MigrationManager::class);
-
         $migrationManager->dropAll();
 
         $this->migrateDatabase();
 
         return $this;
     }
 
+    /**
+     * Creates the migration table. You may override this method to provide more migrations to run for every tests in this file.
+     */
     protected function migrateDatabase(): void
     {
-        $this->migrate(
-            CreateMigrationsTable::class,
-        );
+        $this->migrate(CreateMigrationsTable::class);
     }
 
+    /**
+     * Migrates the specified migration classes.
+     */
     protected function migrate(string|object ...$migrationClasses): void
     {
         $migrationManager = $this->container->get(MigrationManager::class);

tests/Integration/Framework/Commands/MigrateRehashCommandTest.php

@@ -4,7 +4,6 @@
 
 namespace Tests\Tempest\Integration\Framework\Commands;
 
-use PHPUnit\Framework\Assert;
 use Tempest\Console\ExitCode;
 use Tempest\Database\Migrations\Migration;
 use Tempest\Framework\Commands\MigrateFreshCommand;

tests/Integration/Framework/Commands/MigrateValidateCommandTest.php

@@ -4,8 +4,13 @@
 
 namespace Tests\Tempest\Integration\Framework\Commands;
 
+use PHPUnit\Framework\Attributes\PreCondition;
 use Tempest\Console\ExitCode;
+use Tempest\Database\MigratesDown;
 use Tempest\Database\Migrations\Migration;
+use Tempest\Database\Migrations\RunnableMigrations;
+use Tempest\Database\QueryStatement;
+use Tempest\Database\QueryStatements\RawStatement;
 use Tempest\Framework\Commands\MigrateFreshCommand;
 use Tempest\Framework\Commands\MigrateValidateCommand;
 use Tests\Tempest\Integration\FrameworkIntegrationTestCase;
@@ -15,6 +20,20 @@
  */
 final class MigrateValidateCommandTest extends FrameworkIntegrationTestCase
 {
+    #[PreCondition]
+    protected function configure(): void
+    {
+        $this->container->singleton(
+            className: RunnableMigrations::class,
+            definition: new RunnableMigrations(
+                migrations: [
+                    ...iterator_to_array($this->container->get(RunnableMigrations::class)->getIterator()),
+                    new DownMigrationForRehash(),
+                ],
+            ),
+        );
+    }
+
     public function test_migration_validate_command_verifies_valid_migrations(): void
     {
         $this->console
@@ -53,3 +72,13 @@ public function test_migration_validate_command_fails_when_migration_file_is_mis
             ->assertExitCode(ExitCode::ERROR);
     }
 }
+
+final class DownMigrationForRehash implements MigratesDown
+{
+    private(set) string $name = '2025-10-12_down_migration_for_rehash_test';
+
+    public function down(): QueryStatement
+    {
+        return new RawStatement('SELECT 1');
+    }
+}