Created Sniff to validate function without argument

Magento2/Sniffs/Functions/FunctionsDeprecatedWithoutArgumentSniff.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento2\Sniffs\Functions;
+
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Sniffs\Sniff;
+
+/**
+ * Sniff to validate PHP functions usage of which without passing arguments is deprecated.
+ */
+class FunctionsDeprecatedWithoutArgumentSniff implements Sniff
+{
+    /**
+     * String representation of warning.
+     *
+     * @var string
+     */
+    private $warningMessage = 'Calling function %s() without argument is deprecated in PHP 8.1. '
+        . 'Please pass the input to validate as the first argument of the function.';
+
+    /**
+     * Warning violation code.
+     *
+     * @var string
+     */
+    private $warningCode = 'FunctionsDeprecatedWithoutArgument';
+
+    /**
+     * Deprecated functions without argument.
+     *
+     * @var array
+     */
+    private $deprecatedFunctions = [
+        'mb_check_encoding',
+        'get_class',
+        'get_parent_class',
+        'get_called_class'
+    ];
+
+    /**
+     * @inheritdoc
+     */
+    public function register(): array
+    {
+        return [
+            T_OPEN_PARENTHESIS
+        ];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function process(File $phpcsFile, $stackPtr): void
+    {
+        $closeParenthesisPtr = $phpcsFile->findNext(T_CLOSE_PARENTHESIS, $stackPtr);
+        $arguments = trim($phpcsFile->getTokensAsString($stackPtr + 1, $closeParenthesisPtr - $stackPtr - 1));
+
+        if ($arguments) {
+            return;
+        }
+
+        $functionName = $phpcsFile->getTokensAsString($phpcsFile->findPrevious(T_STRING, $stackPtr), 1);
+
+        if (in_array($functionName, $this->deprecatedFunctions)) {
+            $phpcsFile->addWarning(sprintf($this->warningMessage, $functionName), $stackPtr, $this->warningCode);
+        }
+    }
+}

Magento2/Tests/Functions/FunctionsDeprecatedWithoutArgumentUnitTest.inc

@@ -0,0 +1,33 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento2\Tests\Functions;
+
+/**
+ * Class to test validate PHP functions usage of which without passing arguments.
+ */
+class FunctionsDeprecatedWithoutArgument
+{
+    /**
+     * Test deprecation function.
+     *
+     * @return array
+     */
+    public function testDeprecatedMethod(): array
+    {
+        return [
+            mb_check_encoding(), // Calling without argument is deprecated.
+            mb_check_encoding('test-argument', null),
+            get_class(), // Calling without argument is deprecated.
+            get_class(new FunctionsDeprecatedWithoutArgument()),
+            get_parent_class(), // Calling without argument is deprecated.
+            get_parent_class('test-argument'),
+            get_called_class(), // Calling without argument is deprecated.
+            get_called_class('test-argument')
+        ];
+    }
+}

Magento2/Tests/Functions/FunctionsDeprecatedWithoutArgumentUnitTest.php

@@ -0,0 +1,37 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento2\Tests\Functions;
+
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+
+/**
+ * Test to validate PHP functions usage of which without passing arguments.
+ */
+class FunctionsDeprecatedWithoutArgumentUnitTest extends AbstractSniffUnitTest
+{
+    /**
+     * @inheritdoc
+     */
+    public function getErrorList(): array
+    {
+        return [];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getWarningList(): array
+    {
+        return [
+            23 => 1,
+            25 => 1,
+            27 => 1,
+            29 => 1
+        ];
+    }
+}

Magento2/ruleset.xml

@@ -251,6 +251,11 @@
         <exclude-pattern>*Test.php</exclude-pattern>
         <exclude-pattern>*/tests/*</exclude-pattern>
     </rule>
+    <rule ref="Magento2.Functions.FunctionsDeprecatedWithoutArgument">
+        <severity>7</severity>
+        <type>warning</type>
+        <exclude-pattern>*\.xml$</exclude-pattern>
+    </rule>
     <rule ref="Magento2.Namespaces.ImportsFromTestNamespace">
         <severity>8</severity>
         <type>warning</type>