Use refresh indices method. No need for deleting index as recreateIndex does that

tests/src/Kernel/OpenSearchBackendTest.php

@@ -58,18 +58,6 @@ class OpenSearchBackendTest extends BackendTestBase {
     ]);
   }
 
-  /**
-   * {@inheritDoc}
-   */
-  public function tearDown(): void {
-    $server = Server::load($this->serverId);
-    /** @var \Drupal\search_api_opensearch\Plugin\search_api\backend\OpenSearchBackend $backend */
-    $backend = $server->getBackend();
-    $osClient = $backend->getClient();
-    $osClient->indices()->delete(['index' => $this->prefix . $this->indexId]);
-    parent::tearDown();
-  }
-
   /**
    * Tests various indexing scenarios for the search backend.
    *
@@ -102,8 +90,7 @@ class OpenSearchBackendTest extends BackendTestBase {
     $this->recreateIndex();
     $this->insertExampleContent();
     $this->indexItems($this->indexId);
-    // Wait for items to index.
-    sleep(6);
+    $this->refreshIndices();
 
     // Check that all our items are indexed both
     // by tracker and on server.
@@ -143,7 +130,7 @@ class OpenSearchBackendTest extends BackendTestBase {
 
     // Re-index the items for next test.
     $this->indexItems($this->indexId);
-    sleep(6);
+    $this->refreshIndices();
     $this->assertEquals(5, $tracker->getIndexedItemsCount());
     $result = $this->queryAllResults($osClient);
     $this->assertEquals(5, $result['hits']['total']['value']);
@@ -160,7 +147,7 @@ class OpenSearchBackendTest extends BackendTestBase {
 
     // Re-index the items for next test.
     $this->indexItems($this->indexId);
-    sleep(6);
+    $this->refreshIndices();
     $this->assertEquals(5, $tracker->getIndexedItemsCount());
     $result = $this->queryAllResults($osClient);
     $this->assertEquals(5, $result['hits']['total']['value']);