Add RevisionDiscovererFactory to simplify common construction (#15)

Author: ben-challis

README.md

@@ -9,18 +9,15 @@ An SQL database migrations library based on [AMP](https://amphp.org). Currently
 ```php
 use Amp\Mysql\MysqlConfig;
 use Amp\Sync\LocalMutex;
-use Amp\Sync\Mutex;
-use BenChallis\SqlMigrations\ClassDiscovery\Composer\AutoloaderClassDiscovererFactory;
 use BenChallis\SqlMigrations\ClassDiscovery\PhpNamespace;
-use BenChallis\SqlMigrations\Migration\Discovery\RevisionClassDiscoverer;
-use BenChallis\SqlMigrations\Migration\Discovery\RevisionDiscoverer;
+use BenChallis\SqlMigrations\ClassDiscovery\ReadableDirectory;
+use BenChallis\SqlMigrations\Migration\Discovery\RevisionDiscovererFactory;
 use BenChallis\SqlMigrations\Migration\Metadata\MySql\MySqlMetadataStore;
 use BenChallis\SqlMigrations\Migration\Metadata\MySql\MySqlSchemaManager;
 use BenChallis\SqlMigrations\Migration\Metadata\SchemaUpdatingMetadataStore;
 use BenChallis\SqlMigrations\Migration\MigrationCollector;
 use BenChallis\SqlMigrations\Migration\MigrationsFactory;
 use BenChallis\SqlMigrations\Migration\Migrator;
-use BenChallis\SqlMigrations\Migration\Revision\SimpleRevisionFactory;
 use function Amp\Mysql\connect;
 
 $connection = connect(MysqlConfig::fromAuthority(DB_HOST, DB_USER, DB_PASS, DB_DATABASE));
@@ -34,14 +31,9 @@ $migrations = MigrationsFactory::create(
     $metadata,
     new MigrationCollector(
         $metadata, 
-        new RevisionDiscoverer(
-            new RevisionClassDiscoverer(
-                (new AutoloaderClassDiscovererFactory())->fromVendorDirectory(__DIR__.'/vendor')
-            ),
-            new SimpleRevisionFactory(),
-        )
+        RevisionDiscovererFactory::create(ReadableDirectory::fromString(__DIR__.'/vendor')),
     ),
-    PhpNamespace::fromString('App\Migrations')
+    PhpNamespace::fromString('App\Migrations'),
 );
 
 $migrator = new Migrator($migrations, $connection);

src/Migration/Discovery/RevisionDiscovererFactory.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace BenChallis\SqlMigrations\Migration\Discovery;
+
+use BenChallis\SqlMigrations\ClassDiscovery\Composer\AutoloaderClassDiscovererFactory;
+use BenChallis\SqlMigrations\ClassDiscovery\ReadableDirectory;
+use BenChallis\SqlMigrations\Migration\Revision\RevisionFactory;
+use BenChallis\SqlMigrations\Migration\Revision\SimpleRevisionFactory;
+
+final class RevisionDiscovererFactory
+{
+    private function __construct()
+    {
+    }
+
+    public static function create(
+        ReadableDirectory $vendorDirectory,
+        RevisionFactory $revisionFactory = new SimpleRevisionFactory(),
+    ): RevisionDiscoverer {
+        return new RevisionDiscoverer(
+            new RevisionClassDiscoverer(
+                (new AutoloaderClassDiscovererFactory())->fromVendorDirectory($vendorDirectory),
+            ),
+            $revisionFactory,
+        );
+    }
+}