Issue #3262303: Always clear stored validation results when modules are installed or uninstalled

src/Validation/ReadinessValidationManager.php

@@ -120,13 +120,40 @@ class ReadinessValidationManager implements EventSubscriberInterface {
     $results = $event->getResults();
     $this->keyValueExpirable->setWithExpire(
       'readiness_validation_last_run',
-      $results,
+      [
+        'results' => $results,
+        'listeners' => $this->getListenersAsString(ReadinessCheckEvent::class),
+      ],
       $this->resultsTimeToLive * 60 * 60
     );
     $this->keyValueExpirable->set('readiness_check_timestamp', $this->time->getRequestTime());
     return $this;
   }
 
+  /**
+   * Gets all the listeners for a specific event as single string.
+   *
+   * @return string
+   *   The listeners as a string.
+   */
+  protected function getListenersAsString(string $event_name): string {
+    $listeners = $this->eventDispatcher->getListeners($event_name);
+    $string = '';
+    foreach ($listeners as $listener) {
+      if (is_array($listener)) {
+        $string .= is_object($listener[0]) ? get_class($listener[0]) : $listener[0];
+        $string .= $listener[1];
+      }
+      elseif (is_object($listener)) {
+        $string .= "-" . get_class($listener);
+      }
+      elseif (is_string($listener)) {
+        $string .= "-$listener";
+      }
+    }
+    return $string;
+  }
+
   /**
    * Dispatches the readiness check event if there no stored valid results.
    *
@@ -150,11 +177,13 @@ class ReadinessValidationManager implements EventSubscriberInterface {
    *   SystemManager::REQUIREMENT_* constants.
    *
    * @return \Drupal\package_manager\ValidationResult[]|
-   *   The validation result objects or NULL if no results are unavailable or
-   *   no longer valid.
+   *   The validation result objects or NULL if no results are
+   *   available or if the stored results are no longer valid.
+   *
+   * @see self::getStoredValidResults()
    */
   public function getResults(?int $severity = NULL): ?array {
-    $results = $this->keyValueExpirable->get('readiness_validation_last_run');
+    $results = $this->getStoredValidResults();
     if ($results !== NULL) {
       if ($severity !== NULL) {
         $results = array_filter($results, function ($result) use ($severity) {
@@ -166,6 +195,26 @@ class ReadinessValidationManager implements EventSubscriberInterface {
     return NULL;
   }
 
+  /**
+   * Gets stored valid results, if any.
+   *
+   * The stored results are considered valid if the current listeners for the
+   * readiness check event are the same as the last time the event was
+   * dispatched.
+   *
+   * @return \Drupal\package_manager\ValidationResult[]|null
+   *   The stored results if available and still valid, otherwise null.
+   */
+  protected function getStoredValidResults(): ?array {
+    $last_run = $this->keyValueExpirable->get('readiness_validation_last_run');
+
+    // If the listeners have not changed return the results.
+    if ($last_run && $last_run['listeners'] === $this->getListenersAsString(ReadinessCheckEvent::class)) {
+      return $last_run['results'];
+    }
+    return NULL;
+  }
+
   /**
    * Deletes any stored readiness validation results.
    */