Outlined changes for dry run, refs #1

classes/minion/migration/database.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * A faux database connection for doing dry run migrations
+ */
+class Minion_Migration_Database extends Database_MySQL {
+
+	/**
+	 * Creates a disposable instance of the faux connection
+	 * 
+	 * @param array Config for the underlying DB connection
+	 * @return Minion_Migration_Database
+	 */
+	public static function instance(array $config)
+	{
+		return new Minion_Migration_Database('_minion_faux', $config);
+	}
+
+	/**
+	 * The query stack used to store queries
+	 * @var array
+	 */
+	protected $_queries = array();
+
+	/**
+	 * Gets the stack of queries that have been executed
+	 * @return array
+	 */
+	public function get_query_stack()
+	{
+		return $this->_queries;
+	}
+
+	/**
+	 * Resets the query stack to an empty state
+	 * @return Minion_Migration_Database $this
+	 */
+	public function reset_query_stack()
+	{
+		$this->_queries = array();
+
+		return $this;
+	}
+
+	/**
+	 * Appears to allow calling script to execute an SQL query, but merely logs 
+	 * it and returns NULL
+	 *
+	 * @return NULL
+	 */
+	public function query($type, $sql, $as_object = FALSE, array $params = NULL)
+	{
+		$this->_queries[] = $sql;
+
+		return NULL;
+	}
+}

classes/minion/migration/manager.php

@@ -97,9 +97,10 @@ class Minion_Migration_Manager {
 	 * @param  array   Set of locations to update, empty array means all
 	 * @param  array   Versions for specified locations
 	 * @param  boolean The default direction (up/down) for migrations without a specific version
-	 * @return boolean Whether
+	 * @param  boolean Whether successful migrations should be recorded
+	 * @return array   Array of all migrations that were successfully applied
 	 */
-	public function run_migration(array $locations = array(), $versions = array(), $default_direction = TRUE)
+	public function run_migration(array $locations = array(), $versions = array(), $default_direction = TRUE, $record_success = TRUE)
 	{
 		$migrations = $this->_model->fetch_required_migrations($locations, $versions, $default_direction);
 
@@ -109,17 +110,14 @@ class Minion_Migration_Manager {
 
 			foreach($location['migrations'] as $migration)
 			{
-				$file  = Minion_Migration_Util::get_migration_from_filename(
-					$migration['id'], 
-					$migration['location']
-				);
+				$file  = Minion_Migration_Util::get_filename_from_migration($migration);
 
 				if( ! ($file  = Kohana::find_file('migrations', $file)))
 				{
 					throw new Kohana_Exception('Cannot load migration :migration', array(':migration' => $migration['id']));
 				}
 
-				$class = str_replace('-', '_', $migration['id']);
+				$class = Minion_Migration_Util::get_class_from_migration($migration);
 
 				$this->_db->query(NULL, 'START TRANSACTION');
 
@@ -137,8 +135,13 @@ class Minion_Migration_Manager {
 
 					throw $e;
 				}
-
+				
 				$this->_db->query('COMMIT');
+
+				if($record_success)
+				{
+					$this->_model->mark_migration($migration, $location['direction']);
+				}
 			}
 		}
 	}

classes/minion/task/db/migrate.php

@@ -75,18 +75,32 @@ class Minion_Task_Db_Migrate extends Minion_Task
 		$environment         = Arr::get($config, 'environment', 'development');
 		$specified_locations = Arr::get($config, 'locations',   NULL);
 		$versions            = Arr::get($config, 'versions',    NULL);
-		
+		$dry_run             = isset($config['dry-run']);
+
 		$targets   = $this->_parse_target_versions($versions);
 		$locations = $this->_parse_locations($specified_locations);
 
+
 		$db = Database::instance($k_config['db_connections'][$environment]);
 
-		$manager = new Minion_Migration_Manager($db);
+		if($dry_run)
+		{
+			$manager = new Minion_Migration_Manager(
+				Minion_Migration_Database::instance($k_config['db_connections'][$environment]),
+				new Model_Minion_Migration($db)
+			);
+		}
+		else
+		{
+			$manager = new Minion_Migration_Manager($db);
+		}
 
 		$results = $manager
 			// Sync the available migrations with those in the db
 			->sync_migration_files()
-			->run_migration($locations, $targets, $this->_default_direction);
+			// Run migrations for specified locations & versions, and if it's 
+			// a dry run don't log results to DB
+			->run_migration($locations, $targets, $this->_default_direction, ! $dry_run);
 	}
 
 	/**