pdo-document/src/Mapper/StringMapper.php

<?php
/**
 * @author Daniel J. Summers <daniel@bitbadger.solutions>
 * @license MIT
 */

declare(strict_types=1);

namespace BitBadger\PDODocument\Mapper;

/**
 * Map a string result from the named field
 *
 * @implements Mapper<string>
 */
class StringMapper implements Mapper
{
    /**
     * Constructor
     *
     * @param string $fieldName The name of the field to be retrieved as a string
     */
    public function __construct(public string $fieldName) { }

    /**
     * @inheritDoc
     */
    public function map(array $result): ?string
    {
        return match (false) {
            key_exists($this->fieldName, $result) => null,
            is_string($result[$this->fieldName])  => "{$result[$this->fieldName]}",
            default                               => $result[$this->fieldName]
        };
    }
}