Issue #3238647: Create a service for easily accessing Composer information

package_manager/src/ComposerUtility.php

+<?php
+
+namespace Drupal\package_manager;
+
+use Composer\Composer;
+use Composer\Factory;
+use Composer\IO\NullIO;
+use Drupal\Component\Serialization\Json;
+
+/**
+ * Defines a utility object to get information from Composer's API.
+ */
+class ComposerUtility {
+
+  /**
+   * The Composer instance.
+   *
+   * @var \Composer\Composer
+   */
+  protected $composer;
+
+  /**
+   * The statically cached names of the Drupal core packages.
+   *
+   * @var string[]
+   */
+  private static $corePackages;
+
+  /**
+   * Constructs a new ComposerUtility object.
+   *
+   * @param \Composer\Composer $composer
+   *   The Composer instance.
+   */
+  public function __construct(Composer $composer) {
+    $this->composer = $composer;
+  }
+
+  /**
+   * Creates a utility object using the files in a given directory.
+   *
+   * @param string $dir
+   *   The directory that contains composer.json and composer.lock.
+   *
+   * @return \Drupal\package_manager\ComposerUtility
+   *   The utility object.
+   */
+  public static function createForDirectory(string $dir): self {
+    $io = new NullIO();
+    $configuration = $dir . DIRECTORY_SEPARATOR . 'composer.json';
+
+    // The Composer factory requires that either the HOME or COMPOSER_HOME
+    // environment variables be set, so momentarily set the COMPOSER_HOME
+    // variable to the directory we're trying to create a Composer instance for.
+    // We have to do this because the Composer factory doesn't give us a way to
+    // pass the home directory in.
+    // @see \Composer\Factory::getHomeDir()
+    $home = getenv('COMPOSER_HOME');
+    putenv("COMPOSER_HOME=$dir");
+    $composer = Factory::create($io, $configuration);
+    putenv("COMPOSER_HOME=$home");
+
+    return new static($composer);
+  }
+
+  /**
+   * Returns the canonical names of the supported core packages.
+   *
+   * @return string[]
+   *   The canonical list of supported core package names, as listed in
+   *   ../core_packages.json.
+   */
+  protected static function getCorePackageList(): array {
+    if (self::$corePackages === NULL) {
+      $file = __DIR__ . '/../core_packages.json';
+      assert(file_exists($file), "$file does not exist.");
+
+      $core_packages = file_get_contents($file);
+      $core_packages = Json::decode($core_packages);
+
+      assert(is_array($core_packages), "$file did not contain a list of core packages.");
+      self::$corePackages = $core_packages;
+    }
+    return self::$corePackages;
+  }
+
+  /**
+   * Returns the names of the core packages required in composer.json.
+   *
+   * All packages listed in ../core_packages.json are considered core packages.
+   *
+   * @return string[]
+   *   The names of the required core packages.
+   *
+   * @throws \LogicException
+   *   If neither drupal/core or drupal/core-recommended are required.
+   *
+   * @todo Make this return a keyed array of packages, not just names.
+   */
+  public function getCorePackageNames(): array {
+    $requirements = array_keys($this->composer->getPackage()->getRequires());
+
+    // Ensure that either drupal/core or drupal/core-recommended are required.
+    // If neither is, then core cannot be updated, which we consider an error
+    // condition.
+    // @todo Move this check to an update validator as part of
+    //   https://www.drupal.org/project/automatic_updates/issues/3241105
+    $core_requirements = array_intersect(['drupal/core', 'drupal/core-recommended'], $requirements);
+    if (empty($core_requirements)) {
+      $file = $this->composer->getConfig()->getConfigSource()->getName();
+      throw new \LogicException("Drupal core does not appear to be required in $file.");
+    }
+
+    return array_intersect(static::getCorePackageList(), $requirements);
+  }
+
+  /**
+   * Returns all Drupal extension packages in the lock file.
+   *
+   * The following package types are considered Drupal extension packages:
+   * drupal-module, drupal-theme, drupal-custom-module, and drupal-custom-theme.
+   *
+   * @return \Composer\Package\PackageInterface[]
+   *   All Drupal extension packages in the lock file, keyed by name.
+   */
+  public function getDrupalExtensionPackages(): array {
+    $locked_packages = $this->composer->getLocker()
+      ->getLockedRepository(TRUE)
+      ->getPackages();
+
+    $drupal_package_types = [
+      'drupal-module',
+      'drupal-theme',
+      'drupal-custom-module',
+      'drupal-custom-theme',
+    ];
+    $drupal_packages = [];
+    foreach ($locked_packages as $package) {
+      if (in_array($package->getType(), $drupal_package_types, TRUE)) {
+        $key = $package->getName();
+        $drupal_packages[$key] = $package;
+      }
+    }
+    return $drupal_packages;
+  }
+
+}