diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 53040d9a9c531ddc7f570b0578cffd5508fa9224..76b76e644e4749d654b9495bc8b67a3bd0255b47 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,5 +1,6 @@
 Search API 1.x, dev (xxxx-xx-xx):
 ---------------------------------
+- #2933811 by drunken monkey: Fixed coding standards in new Drush code.
 - #2932347 by drunken monkey, ghaya: Fixed case insensitive matching for
   highlighting non-ASCII text.
 - #2938288 by drunken monkey: Fixed problems with PHP 7.2.
diff --git a/src/Commands/SearchApiCommands.php b/src/Commands/SearchApiCommands.php
index ae502a973898afc740bcaf3e98a846ee6b3150b1..f7fdcba88e55a162fdbe4095e0c452f93869dc74 100644
--- a/src/Commands/SearchApiCommands.php
+++ b/src/Commands/SearchApiCommands.php
@@ -66,6 +66,9 @@ class SearchApiCommands extends DrushCommands {
    *
    * @return \Consolidation\OutputFormatters\StructuredData\RowsOfFields
    *   The table rows.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if an index has a server which couldn't be loaded.
    */
   public function listCommand() {
     $rows = $this->commandHelper->indexListCommand();
@@ -85,6 +88,9 @@ class SearchApiCommands extends DrushCommands {
    *   Enable the search index with the ID node_index.
    *
    * @aliases sapi-en,search-api-enable
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if no indexes could be loaded.
    */
   public function enable($indexId) {
     $this->commandHelper->enableIndexCommand([$indexId]);
@@ -101,6 +107,9 @@ class SearchApiCommands extends DrushCommands {
    *   Alias to enable all disabled indexes.
    *
    * @aliases sapi-ena,search-api-enable-all
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if no indexes could be loaded.
    */
   public function enableAll() {
     $this->commandHelper->enableIndexCommand();
@@ -139,6 +148,9 @@ class SearchApiCommands extends DrushCommands {
    *   Alias to disable all enabled indexes.
    *
    * @aliases sapi-disa,search-api-disable-all
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if no indexes could be loaded.
    */
   public function disableAll() {
     $this->commandHelper->disableIndexCommand();
@@ -170,6 +182,9 @@ class SearchApiCommands extends DrushCommands {
    *
    * @return \Consolidation\OutputFormatters\StructuredData\RowsOfFields
    *   The table rows.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set.
    */
   public function status($indexId = NULL) {
     $rows = $this->commandHelper->indexStatusCommand([$indexId]);
@@ -242,6 +257,10 @@ class SearchApiCommands extends DrushCommands {
    *   Schedule the search index with the ID node_index for reindexing.
    *
    * @aliases search-api-mark-all,search-api-reindex,sapi-r,search-api-reset-tracker
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function resetTracker($indexId = NULL, array $options = ['entity-types' => []]) {
     $this->commandHelper->resetTrackerCommand([$indexId], $options['entity-types']);
@@ -264,6 +283,10 @@ class SearchApiCommands extends DrushCommands {
    *   Clear the search index with the ID node_index.
    *
    * @aliases sapi-c,search-api-clear
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function clear($indexId = NULL) {
     $this->commandHelper->clearIndexCommand([$indexId]);
@@ -292,6 +315,12 @@ class SearchApiCommands extends DrushCommands {
    *
    * @return \Consolidation\OutputFormatters\StructuredData\RowsOfFields
    *   The table rows.
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if searching failed for any reason.
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if no search query could be created for the given index, for
+   *   example because it is disabled or its server could not be loaded.
    */
   public function search($indexId, $keyword) {
     $rows = $this->commandHelper->searchIndexCommand($indexId, $keyword);
@@ -318,6 +347,9 @@ class SearchApiCommands extends DrushCommands {
    *
    * @return \Consolidation\OutputFormatters\StructuredData\RowsOfFields
    *   The table rows.
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if no servers could be loaded.
    */
   public function serverList() {
     $rows = $this->commandHelper->serverListCommand();
@@ -339,6 +371,11 @@ class SearchApiCommands extends DrushCommands {
    *   Alias to enable the my_solr_server search server.
    *
    * @aliases sapi-se,search-api-server-enable
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   *   Thrown if an internal error occurred when saving the server.
    */
   public function serverEnable($serverId) {
     $this->commandHelper->enableServerCommand($serverId);
@@ -358,6 +395,11 @@ class SearchApiCommands extends DrushCommands {
    *   Alias to disable the my_solr_server search server.
    *
    * @aliases sapi-sd,search-api-server-disable
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   *   Thrown if an internal error occurred when saving the server.
    */
   public function serverDisable($serverId) {
     $this->commandHelper->disableServerCommand($serverId);
@@ -377,6 +419,12 @@ class SearchApiCommands extends DrushCommands {
    *   Alias to clear all search indexes on the search server my_solr_server.
    *
    * @aliases sapi-sc,search-api-server-clear
+   *
+   * @throws \Drupal\search_api\ConsoleException
+   *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function serverClear($serverId) {
     $this->commandHelper->clearServerCommand($serverId);
diff --git a/src/Utility/CommandHelper.php b/src/Utility/CommandHelper.php
index 7c3ad351a624eae91b418cd925687199c0a0a6a4..ad6fc207ed0966e76227a95acb0413822a031dcf 100644
--- a/src/Utility/CommandHelper.php
+++ b/src/Utility/CommandHelper.php
@@ -2,7 +2,9 @@
 
 namespace Drupal\search_api\Utility;
 
+use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
 use Drupal\Core\Config\Entity\ConfigEntityInterface;
+use Drupal\Core\Entity\EntityStorageException;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\search_api\ConsoleException;
@@ -52,24 +54,28 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @var callable
    */
-  protected $translationMethod;
+  protected $translationFunction;
 
   /**
-   * Constructs a new CommandHelper object.
+   * Constructs a CommandHelper object.
    *
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager.
-   * @param \Drupal\Core\Extension\ModuleHandlerInterface $moduleHandler
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler.
-   * @param string $translationMethod
-   *   A callable for translating strings.
+   * @param string|callable $translation_function
+   *   (optional) A callable for translating strings.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   *   Thrown if the "search_api_index" or "search_api_server" entity types are
+   *   unknown.
    */
-  public function __construct(EntityTypeManagerInterface $entityTypeManager, ModuleHandlerInterface $moduleHandler, $translationMethod = 'dt') {
-    $this->entityTypeManager = $entityTypeManager;
-    $this->indexStorage = $entityTypeManager->getStorage('search_api_index');
-    $this->serverStorage = $entityTypeManager->getStorage('search_api_server');
-    $this->moduleHandler = $moduleHandler;
-    $this->translationMethod = $translationMethod;
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, ModuleHandlerInterface $module_handler, $translation_function = 'dt') {
+    $this->entityTypeManager = $entity_type_manager;
+    $this->indexStorage = $entity_type_manager->getStorage('search_api_index');
+    $this->serverStorage = $entity_type_manager->getStorage('search_api_server');
+    $this->moduleHandler = $module_handler;
+    $this->translationFunction = $translation_function;
   }
 
   /**
@@ -88,6 +94,9 @@ class CommandHelper implements LoggerAwareInterface {
    *     tracked in the index.
    *   - status: Either "enabled" or "disabled".
    *   - limit: The number of items that are processed in a single cron run.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if an index has a server which couldn't be loaded.
    */
   public function indexListCommand() {
     $indexes = $this->loadIndexes();
@@ -137,6 +146,9 @@ class CommandHelper implements LoggerAwareInterface {
    *   - complete: a percentage of indexation.
    *   - indexed: The amount of indexed items.
    *   - total: The total amount of items.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set.
    */
   public function indexStatusCommand(array $indexId = NULL) {
     $indexes = $this->loadIndexes($indexId);
@@ -202,7 +214,7 @@ class CommandHelper implements LoggerAwareInterface {
    *   all indexes will be disabled.
    *
    * @throws \Drupal\search_api\ConsoleException
-   *   If no indexes are defined.
+   *   Thrown if no indexes could be loaded.
    */
   public function disableIndexCommand(array $index_ids = NULL) {
     if (!$this->getIndexCount()) {
@@ -240,6 +252,8 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @throws \Drupal\search_api\ConsoleException
    *   Thrown if an indexing batch process could not be created.
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set.
    */
   public function indexItemsToIndexCommand(array $indexIds = NULL, $limit = NULL, $batchSize = NULL) {
     $indexes = $this->loadIndexes($indexIds);
@@ -316,6 +330,10 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @return bool
    *   TRUE if any index was affected, FALSE otherwise.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function resetTrackerCommand(array $indexIds = NULL, array $entityTypes = []) {
     $indexes = $this->loadIndexes($indexIds);
@@ -361,6 +379,10 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @return bool
    *   TRUE when the clearing was successful, FALSE when no indexes were found.
+   *
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function clearIndexCommand(array $indexIds = NULL) {
     $indexes = $this->loadIndexes($indexIds);
@@ -393,6 +415,9 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @throws \Drupal\search_api\ConsoleException
    *   Thrown if searching failed for any reason.
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if no search query could be created for the given index, for
+   *   example because it is disabled or its server could not be loaded.
    */
   public function searchIndexCommand($indexId, $keyword = NULL) {
     $indexes = $this->loadIndexes([$indexId]);
@@ -442,10 +467,9 @@ class CommandHelper implements LoggerAwareInterface {
    *   - status: The enabled status of the server.
    *
    * @throws \Drupal\search_api\ConsoleException
-   *   Thrown if there aren't any servers yet.
+   *   Thrown if no servers could be loaded.
    */
   public function serverListCommand() {
-    /** @var \Drupal\search_api\ServerInterface[] $servers */
     $servers = $this->loadServers();
     if (count($servers) === 0) {
       throw new ConsoleException($this->t('There are no servers present.'));
@@ -471,14 +495,16 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @throws \Drupal\search_api\ConsoleException
    *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   *   Thrown if an internal error occurred when saving the server.
    */
   public function enableServerCommand($serverId) {
-    $server = $this->loadServers([$serverId]);
-    if (empty($server)) {
+    $servers = $this->loadServers([$serverId]);
+    if (empty($servers)) {
       throw new ConsoleException($this->t('The server could not be loaded.'));
     }
     /** @var \Drupal\search_api\ServerInterface $server */
-    $server = $this->reloadEntityOverrideFree(reset($server));
+    $server = $this->reloadEntityOverrideFree(reset($servers));
     $server->setStatus(TRUE)->save();
   }
 
@@ -490,14 +516,16 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @throws \Drupal\search_api\ConsoleException
    *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\Core\Entity\EntityStorageException
+   *   Thrown if an internal error occurred when saving the server.
    */
   public function disableServerCommand($serverId) {
-    $server = $this->loadServers([$serverId]);
-    if (empty($server)) {
+    $servers = $this->loadServers([$serverId]);
+    if (empty($servers)) {
       throw new ConsoleException($this->t('The server could not be loaded.'));
     }
     /** @var \Drupal\search_api\ServerInterface $server */
-    $server = $this->reloadEntityOverrideFree(reset($server));
+    $server = $this->reloadEntityOverrideFree(reset($servers));
     $server->setStatus(FALSE)->save();
   }
 
@@ -509,14 +537,17 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @throws \Drupal\search_api\ConsoleException
    *   Thrown if the server couldn't be loaded.
+   * @throws \Drupal\search_api\SearchApiException
+   *   Thrown if one of the affected indexes had an invalid tracker set, or some
+   *   other internal error occurred.
    */
   public function clearServerCommand($serverId) {
-    $server = $this->loadServers([$serverId]);
-    if (empty($server)) {
+    $servers = $this->loadServers([$serverId]);
+    if (empty($servers)) {
       throw new ConsoleException($this->t('The server could not be loaded.'));
     }
     /** @var \Drupal\search_api\ServerInterface $server */
-    $server = $this->reloadEntityOverrideFree(reset($server));
+    $server = $this->reloadEntityOverrideFree(reset($servers));
 
     foreach ($server->getIndexes() as $index) {
       $index->clear();
@@ -557,7 +588,7 @@ class CommandHelper implements LoggerAwareInterface {
       $index->save();
       $this->logger->info($this->t('Index @index has been set to use server @server and items have been queued for indexing.', ['@index' => $indexId, '@server' => $serverId]));
     }
-    catch (SearchApiException $e) {
+    catch (EntityStorageException $e) {
       $this->logger->warning($e->getMessage());
       $this->logger->warning($this->t('There was an error setting index @index to use server @server, or this index is already configured to use this server.', ['@index' => $indexId, '@server' => $serverId]));
     }
@@ -568,13 +599,14 @@ class CommandHelper implements LoggerAwareInterface {
    *
    * @param array|null $indexIds
    *   (optional) The IDs of the search indexes to return, or NULL to load all
-   *   indexes.
+   *   indexes. An array with a single NULL value is interpreted the same way as
+   *   passing NULL.
    *
    * @return \Drupal\search_api\IndexInterface[]
    *   An array of search indexes.
    */
   public function loadIndexes(array $indexIds = NULL) {
-    if (count($indexIds) === 1 && $indexIds === [NULL]) {
+    if ($indexIds === [NULL]) {
       $indexIds = NULL;
     }
     return $this->indexStorage->loadMultiple($indexIds);
@@ -641,9 +673,14 @@ class CommandHelper implements LoggerAwareInterface {
    *   loaded.
    */
   public function reloadEntityOverrideFree(ConfigEntityInterface $entity) {
-    /** @var \Drupal\Core\Config\Entity\ConfigEntityStorageInterface $storage */
-    $storage = $this->entityTypeManager->getStorage($entity->getEntityTypeId());
-    return $storage->loadOverrideFree($entity->id());
+    try {
+      /** @var \Drupal\Core\Config\Entity\ConfigEntityStorageInterface $storage */
+      $storage = $this->entityTypeManager->getStorage($entity->getEntityTypeId());
+      return $storage->loadOverrideFree($entity->id());
+    }
+    catch (InvalidPluginDefinitionException $e) {
+      return NULL;
+    }
   }
 
   /**
@@ -658,7 +695,7 @@ class CommandHelper implements LoggerAwareInterface {
    *   The translated message.
    */
   public function t($message, array $arguments = []) {
-    return call_user_func_array($this->translationMethod, [
+    return call_user_func_array($this->translationFunction, [
       $message,
       $arguments,
     ]);