Add more linters to improve code readability (#19989)

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

1 files changed, 1 insertions, 1 deletions

diff --git a/services/mailer/mail_test.go b/services/mailer/mail_test.go
index 83955a5896..93837ba8c4 100644
--- a/services/mailer/mail_test.go
+++ b/services/mailer/mail_test.go
@@ -61,7 +61,7 @@ func prepareMailerTest(t *testing.T) (doer *user_model.User, repo *repo_model.Re
 	issue = unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: 1, Repo: repo, Poster: doer}).(*issues_model.Issue)
 	assert.NoError(t, issue.LoadRepo(db.DefaultContext))
 	comment = unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ID: 2, Issue: issue}).(*issues_model.Comment)
-	return
+	return doer, repo, issue, comment
 }
 
 func TestComposeIssueCommentMessage(t *testing.T) {

path: root/services/mailer/mail_test.go

<?php
/**
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 *
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Victor Dubiniuk <dubiniuk@owncloud.com>
 *
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

use OC\Console\Application;
use Symfony\Component\Console\Input\ArgvInput;
use Symfony\Component\Console\Output\ConsoleOutput;

define('OC_CONSOLE', 1);

// Show warning if a PHP version below 5.6.0 is used, this has to happen here
// because base.php will already use 5.6 syntax.
if (version_compare(PHP_VERSION, '5.6.0') === -1) {
	echo 'This version of Nextcloud requires at least PHP 5.6.0'.PHP_EOL;
	echo 'You are currently running ' . PHP_VERSION . '. Please update your PHP version.'.PHP_EOL;
	return;
}

function exceptionHandler($exception) {
	echo "An unhandled exception has been thrown:" . PHP_EOL;
	echo $exception;
	exit(1);
}
try {
	require_once __DIR__ . '/lib/base.php';

	// set to run indefinitely if needed
	set_time_limit(0);

	if (!OC::$CLI) {
		echo "This script can be run from the command line only" . PHP_EOL;
		exit(1);
	}

	set_exception_handler('exceptionHandler');

	if (!function_exists('posix_getuid')) {
		echo "The posix extensions are required - see http://php.net/manual/en/book.posix.php" . PHP_EOL;
		exit(1);
	}
	$user = posix_getpwuid(posix_getuid());
	$configUser = posix_getpwuid(fileowner(OC::$configDir . 'config.php'));
	if ($user['name'] !== $configUser['name']) {
		echo "Console has to be executed with the user that owns the file config/config.php" . PHP_EOL;
		echo "Current user: " . $user['name'] . PHP_EOL;
		echo "Owner of config.php: " . $configUser['name'] . PHP_EOL;
		echo "Try adding 'sudo -u " . $configUser['name'] . " ' to the beginning of the command (without the single quotes)" . PHP_EOL;
		exit(1);
	}

	$oldWorkingDir = getcwd();
	if ($oldWorkingDir === false) {
		echo "This script can be run from the ownCloud root directory only." . PHP_EOL;
		echo "Can't determine current working dir - the script will continue to work but be aware of the above fact." . PHP_EOL;
	} else if ($oldWorkingDir !== __DIR__ && !chdir(__DIR__)) {
		echo "This script can be run from the ownCloud root directory only." . PHP_EOL;
		echo "Can't change to ownCloud root directory." . PHP_EOL;
		exit(1);
	}

	if (!function_exists('pcntl_signal') && !in_array('--no-warnings', $argv)) {
		echo "The process control (PCNTL) extensions are required in case you want to interrupt long running commands - see http://php.net/manual/en/book.pcntl.php" . PHP_EOL;
	}

	$application = new Application(\OC::$server->getConfig(), \OC::$server->getEventDispatcher(), \OC::$server->getRequest(), \OC::$server->getLogger());
	$application->loadCommands(new ArgvInput(), new ConsoleOutput());
	$application->run();
} catch (Exception $ex) {
	exceptionHandler($ex);
} catch (Error $ex) {
	exceptionHandler($ex);
}