MAGETWO-83266: Prohibit global variables and output buffering with Code Sniffer

Author: Alex Paliarush

dev/tests/static/framework/Magento/Sniffs/MagentoModule/ForbiddenFunctionsSniff.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Sniffs\MagentoModule;
+
+/**
+ * Sniff prohibiting usage of certain functions in Magento modules.
+ */
+class ForbiddenFunctionsSniff extends \PHP_CodeSniffer\Standards\Generic\Sniffs\PHP\ForbiddenFunctionsSniff
+{
+    public $forbiddenFunctions = ['ob_start' => null];
+
+    /**
+     * @inheritdoc
+     */
+    protected function addError($phpcsFile, $stackPtr, $function, $pattern = null)
+    {
+        $data = [$function];
+        $error = 'The usage of %s() in Magento modules is forbidden';
+        $type = 'Found';
+
+        if ($this->error === true) {
+            $phpcsFile->addError($error, $stackPtr, $type, $data);
+        } else {
+            $phpcsFile->addWarning($error, $stackPtr, $type, $data);
+        }
+    }
+}

dev/tests/static/framework/Magento/Sniffs/MagentoModule/GlobalVariablesSniff.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Sniffs\MagentoModule;
+
+use PHP_CodeSniffer\Sniffs\Sniff;
+use PHP_CodeSniffer\Files\File;
+
+/**
+ * Sniff prohibiting usage of global variables in Magento modules.
+ */
+class GlobalVariablesSniff implements Sniff
+{
+    /**
+     * @inheritdoc
+     */
+    public function register()
+    {
+        return [T_VARIABLE];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        $tokens = $phpcsFile->getTokens();
+        if (preg_match('/^\$[_A-Z0-9]+$/', $tokens[$stackPtr]['content'])) {
+            $phpcsFile->addError(
+                'Usage of global variables in modules is not allowed: ' . $tokens[$stackPtr]['content'],
+                $stackPtr,
+                'ERROR'
+            );
+            return;
+        }
+    }
+}

dev/tests/static/framework/Magento/ruleset.xml

@@ -19,6 +19,12 @@
     <rule ref="Magento.LiteralNamespaces.LiteralNamespaces">
         <exclude-pattern>*/_files/*</exclude-pattern>
     </rule>
+    <rule ref="Magento.MagentoModule.ForbiddenFunctions">
+        <include-pattern>*/(app/code|vendor)/*</include-pattern>
+    </rule>
+    <rule ref="Magento.MagentoModule.GlobalVariables">
+        <include-pattern>*/(app/code|vendor)/*</include-pattern>
+    </rule>
 
     <rule ref="Generic.Functions.CallTimePassByReference"/>
     <rule ref="Generic.PHP.DeprecatedFunctions"/>