PriorityCallbacks: Execute callbacks before Codeception's

GitPreparer now registers a "priority" register_shutdown_function
callback in order to clean up in case of a fatal error.

lib/PriorityCallbacks.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * Execute callbacks before Codeception does
+ */
+
+class PriorityCallbacks
+{
+	/** @var array */
+	private $shutdown_functions = [];
+
+	private function __construct()
+	{
+		register_shutdown_function([$this, 'call_shutdown_functions']);
+	}
+
+	public static function instance()
+	{
+		static $instance = null;
+		if (!$instance instanceof self)
+		{
+			$instance = new static();
+		}
+		return $instance;
+	}
+
+	public function call_shutdown_functions()
+	{
+		foreach ($this->shutdown_functions as $shutdown_function)
+		{
+			call_user_func($shutdown_function);
+		}
+	}
+
+	public function register_shutdown_function($callable)
+	{
+		$this->shutdown_functions[] = $callable;
+	}
+
+	private function __clone() {}
+
+	private function __sleep() {}
+
+	private function __wakeup() {}
+}
+
+PriorityCallbacks::instance();

lib/preparers/GitPreparer.php

@@ -17,6 +17,9 @@ class GitPreparer implements Preparer
 
 	protected function setVcsInProgress()
 	{
+		// Cleanup in case of a fatal error
+		PriorityCallbacks::instance()->register_shutdown_function([$this, 'rollback']);
+
 		if ($this->isVcsInProgress())
 		{
 			$this->debug('Git repo shows test in progress. Probably crashed test.');

tests/_bootstrap.php

@@ -12,3 +12,6 @@ if (substr($app_path, 0, 1) !== '/')
 
 define('APP_PATH', realpath($app_path));
 define('PARAMS_SERIALIZED', serialize($params));
+
+// Provide a way to register callbacks that execute before Codeception's
+include(codecept_root_dir()."/lib/PriorityCallbacks.php");