Add error validation messages

password_policy-validation_message.patch

diff --git a/password_policy.module b/password_policy.module
index 6b8d956..edd5c5b 100644
--- a/password_policy.module
+++ b/password_policy.module
@@ -10,6 +10,7 @@ use Drupal\password_policy\Entity\PasswordPolicy;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\user\UserInterface;
+use Drupal\Component\Render\FormattableMarkup;
 
 /**
  * Implements hook_form_FORM_ID_alter() for user_form().
@@ -231,6 +232,7 @@ function _password_policy_constraints_validate(&$form, FormStateInterface &$form
       $user_context_values[$user_context_field] = $form['account'][$user_context_field]['#default_value'];
     }
   }
+  $error_messages = [t('The password does not satisfy the password policies.')];
   /** @var \Drupal\password_policy\Entity\PasswordPolicy $policy */
   foreach ($applicable_policies as $policy_id => $policy) {
     $policy_constraints = $policy->getConstraints();
@@ -274,8 +276,9 @@ function _password_policy_constraints_validate(&$form, FormStateInterface &$form
         $policies_table_rows[] = $table_row;
       }
       else {
-        if (!$validation->isValid() and !$failed and $form_state->getValue('pass') != '') {
+        if (!$validation->isValid() and $form_state->getValue('pass') != '') {
           // Throw error to ensure form will not submit.
+          $error_messages[] = $validation->getErrorMessage();
           $failed = TRUE;
         }
         elseif ($force_failure) {
@@ -285,7 +288,8 @@ function _password_policy_constraints_validate(&$form, FormStateInterface &$form
     }
   }
   if ($failed && !$generate_policy_table) {
-    $form_state->setErrorByName('pass', t('The password does not satisfy the password policies.'));
+    array_shift($error_messages);
+    $error_message = implode('<br/>', $error_messages);
+    $form_state->setErrorByName('pass', new FormattableMarkup($error_message, []));
   }
   if ($generate_policy_table) {
     return $policies_table_rows;