diff --git a/tests/functional/search/base.php b/tests/functional/search/base.php
index 004ee13c25..ed0acc12bd 100644
--- a/tests/functional/search/base.php
+++ b/tests/functional/search/base.php
@@ -16,25 +16,37 @@
 */
 abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 {
-	protected function assert_search_found($keywords, $posts_found, $words_highlighted)
+	protected function assert_search_found($keywords, $posts_found, $words_highlighted, $sort_key = '')
 	{
 		$this->purge_cache();
-		$crawler = self::request('GET', 'search.php?keywords=' . $keywords);
+		$crawler = self::request('GET', 'search.php?keywords=' . $keywords . ($sort_key ? "&sk=$sort_key" : ''));
 		$this->assertEquals($posts_found, $crawler->filter('.postbody')->count(), $this->search_backend);
 		$this->assertEquals($words_highlighted, $crawler->filter('.posthilit')->count(), $this->search_backend);
 		$this->assertStringContainsString("Search found $posts_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
 	}
 
-	protected function assert_search_found_topics($keywords, $topics_found)
+	protected function assert_search_found_topics($keywords, $topics_found, $sort_key = '')
 	{
 		$this->purge_cache();
-		$crawler = self::request('GET', 'search.php?sr=topics&keywords=' . $keywords);
-		$html = '';
-		foreach ($crawler as $domElement) {
-			$html .= $domElement->ownerDocument->saveHTML($domElement);
-		}
-		$this->assertEquals($topics_found, $crawler->filter('.row')->count(), $html);
-		$this->assertStringContainsString("Search found $topics_found match", $crawler->filter('.searchresults-title')->text(), $html);
+		$crawler = self::request('GET', 'search.php?sr=topics&keywords=' . $keywords . ($sort_key ? "&sk=$sort_key" : ''));
+		$this->assertEquals($topics_found, $crawler->filter('.row')->count(), $this->search_backend);
+		$this->assertStringContainsString("Search found $topics_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
+	}
+
+	protected function assert_search_posts_by_author($author, $posts_found, $sort_key = '')
+	{
+		$this->purge_cache();
+		$crawler = self::request('GET', 'search.php?author=' . $author . ($sort_key ? "&sk=$sort_key" : ''));
+		$this->assertEquals($posts_found, $crawler->filter('.postbody')->count(), $this->search_backend);
+		$this->assertStringContainsString("Search found $posts_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
+	}
+
+	protected function assert_search_topics_by_author($author, $topics_found, $sort_key = '')
+	{
+		$this->purge_cache();
+		$crawler = self::request('GET', 'search.php?sr=topics&author=' . $author . ($sort_key ? "&sk=$sort_key" : ''));
+		$this->assertEquals($topics_found, $crawler->filter('.row')->count(), $this->search_backend);
+		$this->assertStringContainsString("Search found $topics_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
 	}
 
 	protected function assert_search_not_found($keywords)
@@ -45,8 +57,27 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 		$this->assertEquals($split_keywords_string, $crawler->filter('#keywords')->attr('value'), $this->search_backend);
 	}
 
+	protected function assert_search_for_author_not_found($author)
+	{
+		$this->add_lang('search');
+		$crawler = self::request('GET', 'search.php?author=' . $author);
+		$this->assertContainsLang('NO_SEARCH_RESULTS', $crawler->text(), $this->search_backend);
+	}
+
 	public function test_search_backend()
 	{
+		// Create a new standard user if needed, topic and post to test searh for author
+		if (!$this->user_exists('searchforauthoruser'))
+		{
+			$searchforauthoruser_id = $this->create_user('searchforauthoruser');
+		}
+		$this->remove_user_group('NEWLY_REGISTERED', ['searchforauthoruser']);
+		$this->disable_flood_interval();
+		$this->login('searchforauthoruser');
+		$topic_by_author = $this->create_topic(2, 'Test Topic from searchforauthoruser', 'This is a test topic posted by searchforauthoruser to test searching by author.');
+		$this->create_post(2, $topic_by_author['topic_id'], 'Re: Test Topic from searchforauthoruser', 'This is a test post posted by searchforauthoruser');
+		$this->logout();
+
 		$this->login();
 		$this->admin_login();
 
@@ -54,6 +85,7 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 
 		$post = $this->create_topic(2, 'Test Topic 1 foosubject', 'This is a test topic posted by the barsearch testing framework.');
 
+
 		$crawler = self::request('GET', 'adm/index.php?i=acp_search&mode=settings&sid=' . $this->sid);
 		$form = $crawler->selectButton('Submit')->form();
 		$values = $form->getValues();
@@ -72,6 +104,7 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 			if ($crawler->filter('.errorbox')->count() > 0)
 			{
 				$this->delete_topic($post['topic_id']);
+				$this->delete_topic($topic_by_author['topic_id']);
 				$this->markTestSkipped("Search backend is not supported/running");
 			}
 
@@ -79,20 +112,29 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 		}
 
 		$this->logout();
-		$this->assert_search_found('phpbb3+installation', 1, 3);
-		$this->assert_search_found('foosubject+barsearch', 1, 2);
-		$this->assert_search_found_topics('phpbb3+installation', 1);
-		$this->assert_search_found_topics('foosubject+barsearch', 1);
+
+		foreach (['', 'a', 't', 'f', 'i', 's'] as $sort_key)
+		{
+			$this->assert_search_found('phpbb3+installation', 1, 3, $sort_key);
+			$this->assert_search_found('foosubject+barsearch', 1, 2, $sort_key);
+			$this->assert_search_found('barsearch-testing', 1, 2, $sort_key); // test hyphen ignored
+			$this->assert_search_found('barsearch+-+testing', 1, 2, $sort_key); // test hyphen wrapped with space ignored
+			$this->assert_search_found_topics('phpbb3+installation', 1, $sort_key);
+			$this->assert_search_found_topics('foosubject+barsearch', 1, $sort_key);
+
+			$this->assert_search_posts_by_author('searchforauthoruser', 2, $sort_key);
+			$this->assert_search_topics_by_author('searchforauthoruser', 1, $sort_key);
+		}
 
 		$this->assert_search_not_found('loremipsumdedo');
-		$this->assert_search_found('barsearch-testing', 1, 2); // test hyphen ignored
-		$this->assert_search_found('barsearch+-+testing', 1, 2); // test hyphen wrapped with space ignored
 		$this->assert_search_not_found('barsearch+-testing'); // test excluding keyword
+		$this->assert_search_for_author_not_found('authornotexists');
 
 		$this->login();
 		$this->admin_login();
 		$this->delete_search_index();
 		$this->delete_topic($post['topic_id']);
+		$this->delete_topic($topic_by_author['topic_id']);
 	}
 
 	protected function create_search_index($backend = null)
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 824dc2811a..35a1338850 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -1437,4 +1437,112 @@ class phpbb_functional_test_case extends phpbb_test_case
 
 		return $file_form_data;
 	}
+
+	/**
+	 * Get HTML of the crawler
+	 * See https://symfony.com/doc/current/components/dom_crawler.html#component-dom-crawler-dumping
+	 *
+	 * @param Symfony\Component\DomCrawler\Crawler $crawler Crawler instance
+	 * @param string $url Request URL
+	 *
+	 * @return array Hidden form fields array
+	 */
+	protected function dump_crawler($crawler)
+	{
+		if (!$crawler)
+		{
+			return;
+		}
+
+		$html = '';
+		foreach ($crawler as $domElement)
+		{
+			$html .= $domElement->ownerDocument->saveHTML($domElement);
+		}
+
+		return $html;
+	}
+
+	/**
+	 * Get username of currently logged in user
+	 *
+	 * @return string|bool username if logged in, false otherwise
+	 */
+	protected function get_logged_in_user()
+	{
+		$username_logged_in = false;
+		$crawler = self::request('GET', 'index.php');
+		$is_logged_in = strpos($crawler->filter('div[class="navbar"]')->text(), 'Login') === false;
+		if ($is_logged_in)
+		{
+			$username_logged_in = $crawler->filter('li[id="username_logged_in"] > div > a > span')->text();
+		}
+		return $username_logged_in;
+	}
+
+	/**
+	 * Disable posting flood control
+	 */
+	protected function disable_flood_interval()
+	{
+		$relogin_back = false;
+		$logged_in_username = $this->get_logged_in_user();
+		if ($logged_in_username && $logged_in_username !== 'admin')
+		{
+			$this->logout();
+			$relogin_back = true;
+		}
+
+		if (!$logged_in_username || $relogin_back)
+		{
+			$this->login();
+			$this->admin_login();
+		}
+
+		$this->add_lang('acp/common');
+		$crawler = self::request('GET', 'adm/index.php?i=acp_board&mode=post&sid=' . $this->sid);
+		$form = $crawler->selectButton('submit')->form([
+			'config[flood_interval]'	=> 0,
+		]);
+		$crawler = self::submit($form);
+		$this->assertContainsLang('CONFIG_UPDATED', $crawler->text());
+
+		// Get logged out back or get logged in in user back if needed
+		if (!$logged_in_username)
+		{
+			$this->logout();
+		}
+
+		if ($relogin_back)
+		{
+			$this->logout();
+			$this->login($logged_in_username);
+		}
+	}
+
+	/**
+	* Check if a user exists by username(s) or user_id(s)
+	*
+	* @param array &$user_id_ary The user ids to check or empty if usernames used
+	* @param array &$username_ary The usernames to check or empty if user ids used
+	*
+	* @return bool Returns true if a user exists, false otherwise
+	*/
+	protected function user_exists($username, $user_id = null)
+	{
+		global $db;
+
+		$db = $this->get_db();
+
+		if (!function_exists('utf_clean_string'))
+		{
+			require_once(__DIR__ . '/../../phpBB/includes/utf/utf_tools.php');
+		}
+		if (!function_exists('user_get_id_name'))
+		{
+			require_once(__DIR__ . '/../../phpBB/includes/functions_user.php');
+		}
+
+		return user_get_id_name($user_id, $username) ? false : true;
+	}
 }