drush_plugin__composer_check/ComposerCheck/RequirementsLoader.php

<?php

namespace Fgm\ComposerCheck;

/**
 * Class RequirementsLoader loads a composer.json file.
 */
class RequirementsLoader implements LoaderInterface {

  protected $dev = [];

  protected $run = [];

  /**
   * {@inheritdoc}
   */
  public function __construct(string $directory) {
    $this->file = realpath("${directory}/composer.json");
  }

  /**
   * Return the --dev requirements.
   *
   * @return array
   *   A requirements array, keyed by requirement string.
   */
  public function getDev() {
    return $this->dev;
  }

  /**
   * Return the non- --dev requirements.
   *
   * @return array
   *   A requirements array, keyed by requirement string.
   */
  public function getRun() {
    return $this->run;
  }

  /**
   * {@inheritdoc}
   */
  public function load() {
    $json = json_decode(file_get_contents($this->file), TRUE);
    $this->run = $json['require'] ?? [];
    $this->dev = $json['require-dev'] ?? [];
  }

}