Installation

I will install rector on the system where TYPO3 is installed in composer mode. If you are not using a composer mode, then follow the steps outlined here..

Go to the root page of TYPO3 installation where the composer.json file is situated and run the following command

composer require --dev rector/rector

Running

To run rector, you first have to create a configuration file. To create it, run the following.

vendor/bin/rector init --template-type=typo3

A new file named rector.php is created in the same folder. Have a look at the configuration file and change/modify as necessary. For this tutorial, I will change Typo3LevelSetList::UP_TO_TYPO3_11 to Typo3LevelSetList::UP_TO_TYPO3_10 and set the following to true

$parameters->set(Option::AUTO_IMPORT_NAMES, true);
$parameters->set(Option::IMPORT_DOC_BLOCKS, false);

Now you can run rector with the following command.

vendor/bin/rector process packages/my_custom_extension --dry-run

Note: Once everything seems okay you can remove --dry-run and run it to apply the changes