Add rector to auto migrate to TYPO3 v10

composer.json

@@ -27,5 +27,8 @@
         "typo3/cms": {
             "extension-key": "events"
         }
+    },
+    "require-dev": {
+        "ssch/typo3-rector": "^0.8.0"
     }
 }

rector.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Core\Configuration\Option;
+use Rector\Core\ValueObject\PhpVersion;
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use Ssch\TYPO3Rector\Set\Typo3SetList;
+use Ssch\TYPO3Rector\Configuration\Typo3Option;
+use Ssch\TYPO3Rector\PostRector\NameImportingPostRector;
+use Ssch\TYPO3Rector\Rector\v9\v0\InjectAnnotationRector;
+
+return static function (ContainerConfigurator $containerConfigurator): void {
+    // get parameters
+    $parameters = $containerConfigurator->parameters();
+
+    // Define what rule sets will be applied
+    $parameters->set(Option::SETS, [
+        Typo3SetList::TYPO3_104,
+    ]);
+
+    // FQN classes are not imported by default. If you don't do it manually after every Rector run, enable it by:
+    $parameters->set(Typo3Option::AUTO_IMPORT_NAMES, true);
+
+    // this will not import root namespace classes, like \DateTime or \Exception
+    $parameters->set(Option::IMPORT_SHORT_CLASSES, false);
+
+    // this will not import classes used in PHP DocBlocks, like in /** @var \Some\Class */
+    $parameters->set(Option::IMPORT_DOC_BLOCKS, false);
+
+    // Define your target version which you want to support
+    $parameters->set(Option::PHP_VERSION_FEATURES, PhpVersion::PHP_73);
+
+    // If you would like to see the changelog url when a rector is applied
+    $parameters->set(Typo3Option::OUTPUT_CHANGELOG, true);
+
+    // If you set option Typo3Option::AUTO_IMPORT_NAMES to true, you should consider excluding some TYPO3 files.
+    $parameters->set(Option::SKIP, [
+        NameImportingPostRector::class => [
+            'ClassAliasMap.php',
+            'class.ext_update.php',
+            'ext_localconf.php',
+            'ext_emconf.php',
+            'ext_tables.php',
+            __DIR__ . '/**/TCA/*',
+        ],
+    ]);
+
+    // If you have trouble that rector cannot run because some TYPO3 constants are not defined add an additional constants file
+    // Have a look at https://github.com/sabbelasichon/typo3-rector/blob/master/typo3.constants.php
+    // $parameters->set(Option::AUTOLOAD_PATHS, [
+    //     __DIR__ . '/typo3.constants.php'
+    // ]);
+
+    // get services (needed for register a single rule)
+    // $services = $containerConfigurator->services();
+
+    // register a single rule
+    // $services->set(InjectAnnotationRector::class);
+};