Issue #3507468: EnabledSourceHandler's query result caching should also consider the contents of composer.lock

Closes #3507468

src/EnabledSourceHandler.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\project_browser;
 
+use Composer\InstalledVersions;
 use Drupal\Component\Serialization\Json;
 use Drupal\Core\Config\ConfigCrudEvent;
 use Drupal\Core\Config\ConfigEvents;
@@ -109,7 +110,7 @@ class EnabledSourceHandler implements LoggerAwareInterface, EventSubscriberInter
    */
   public function getProjects(string $source_id, array $query = []): ProjectsResultsPage {
     // Cache only exact query, down to the page number.
-    $cache_key = 'query:' . md5(Json::encode($query));
+    $cache_key = $this->getQueryCacheKey($query);
 
     $storage = $this->keyValue($source_id);
 
@@ -144,6 +145,27 @@ class EnabledSourceHandler implements LoggerAwareInterface, EventSubscriberInter
     return $results;
   }
 
+  /**
+   * Generates a cache key for a specific query.
+   *
+   * @param array $query
+   *   The query.
+   *
+   * @return string
+   *   A cache key for the given query.
+   */
+  private function getQueryCacheKey(array $query): string {
+    // Include a quick hash of the top-level `composer.lock` file in the hash,
+    // so that sources which base their queries on the state of the local site
+    // will be refreshed when the local site changes.
+    ['install_path' => $project_root] = InstalledVersions::getRootPackage();
+    $lock_file = $project_root . DIRECTORY_SEPARATOR . 'composer.lock';
+    $lock_file_hash = file_exists($lock_file)
+      ? hash_file('xxh64', $lock_file)
+      : '';
+    return 'query:' . md5(Json::encode($query) . $lock_file_hash);
+  }
+
   /**
    * Queries the specified source.
    *