Magento 2 : Add Quote Item / Order Item attribute (Patch/Schema)

AddCustomQuoteItemOrderItemAttribute.php

<?php
/**
 * @license http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 * @author Phuong LE <[email protected]>
 * @copyright Copyright (c) 2020 Men In Code Ltd (https://www.menincode.com)
 */

namespace MyNamespace\MyModule\Setup\Patch\Schema;

use Magento\Framework\DB\Ddl\Table;
use Magento\Framework\Setup\Patch\SchemaPatchInterface;


class AddCustomQuoteItemOrderItemAttribute implements SchemaPatchInterface
{
    /**
     * @var \Magento\Quote\Setup\QuoteSetup
     */
    private $quoteSetup;
    /**
     * @var \Magento\Sales\Setup\SalesSetup
     */
    private $salesSetup;

    /**
     * AddCustomQuoteItemOrderItemAttribute constructor.
     * @param \Magento\Quote\Setup\QuoteSetup $quoteSetup
     * @param \Magento\Sales\Setup\SalesSetup $salesSetup
     */
    public function __construct(
        \Magento\Quote\Setup\QuoteSetup $quoteSetup,
        \Magento\Sales\Setup\SalesSetup $salesSetup
    ) {
        $this->quoteSetup = $quoteSetup;
        $this->salesSetup = $salesSetup;
    }

    /**
     * @return string[]
     */
    public static function getDependencies()
    {
        return [];
    }

    /**
     * @return string[]
     */
    public function getAliases()
    {
        return [];

    }

    /**
     * @return AddCustomQuoteItemOrderItemAttribute|void
     */
    public function apply()
    {
        $this->quoteSetup->addAttribute(
            'quote_item',
            'custom_attribute',
            [
                'type' => Table::TYPE_TEXT,
                'nullable' => true,
                'comment' => 'custom attribute'
            ]
        );

        $this->salesSetup->addAttribute(
            'order_item',
            'custom_attribute',
            [
                'type' => Table::TYPE_TEXT,
                'nullable' => true,
                'comment' => 'custom attribute'
            ]
        );
    }
}