Add allow-underscore option for CamelCaseParameterName & CamelCaseVariableName

src/main/php/PHPMD/Rule/Controversial/CamelCaseParameterName.php

@@ -40,7 +40,7 @@ class CamelCaseParameterName extends AbstractRule implements MethodAware, Functi
     public function apply(AbstractNode $node)
     {
         foreach ($node->getParameters() as $parameter) {
-            if (!preg_match('/^\$[a-z][a-zA-Z0-9]*$/', $parameter->getName())) {
+            if (!$this->isValid($parameter->getName())) {
                 $this->addViolation(
                     $node,
                     array(
@@ -50,4 +50,13 @@ public function apply(AbstractNode $node)
             }
         }
     }
+
+    private function isValid($parameterName)
+    {
+        if ($this->getBooleanProperty('allow-underscore')) {
+            return preg_match('/^\$[_]?[a-z][a-zA-Z0-9]*$/', $parameterName);
+        }
+
+        return preg_match('/^\$[a-z][a-zA-Z0-9]*$/', $parameterName);
+    }
 }

src/main/php/PHPMD/Rule/Controversial/CamelCaseVariableName.php

@@ -57,21 +57,39 @@ class CamelCaseVariableName extends AbstractRule implements MethodAware, Functio
     public function apply(AbstractNode $node)
     {
         foreach ($node->findChildrenOfType('Variable') as $variable) {
-            $image = $variable->getImage();
-
-            if (in_array($image, $this->exceptions)) {
-                continue;
+            if (!$this->isValid($variable)) {
+                $this->addViolation(
+                    $node,
+                    array(
+                        $variable->getImage(),
+                    )
+                );
             }
+        }
+    }
 
-            if (preg_match('/^\$[a-z][a-zA-Z0-9]*$/', $image)) {
-                continue;
-            }
+    private function isValid($variable)
+    {
+        $image = $variable->getImage();
 
-            if ($variable->getParent()->isInstanceOf('PropertyPostfix')) {
-                continue;
+        if (in_array($image, $this->exceptions)) {
+            return true;
+        }
+
+        if ($this->getBooleanProperty('allow-underscore')) {
+            if (preg_match('/^\$[_]?[a-z][a-zA-Z0-9]*$/', $image)) {
+                return true;
             }
+        }
 
-            $this->addViolation($node, array($image));
+        if (preg_match('/^\$[a-z][a-zA-Z0-9]*$/', $image)) {
+            return true;
         }
+
+        if ($variable->getParent()->isInstanceOf('PropertyPostfix')) {
+            return true;
+        }
+
+        return false;
     }
 }

src/main/resources/rulesets/controversial.xml

@@ -122,7 +122,11 @@ It is considered best practice to use the camelCase notation to name parameters.
             ]]>
         </description>
         <priority>1</priority>
-        <properties />
+        <properties>
+            <property name="allow-underscore"
+                      description="Allow an optional, single underscore at the beginning."
+                      value="false" />
+        </properties>
         <example>
             <![CDATA[
 class ClassName {
@@ -144,7 +148,11 @@ It is considered best practice to use the camelCase notation to name variables.
             ]]>
         </description>
         <priority>1</priority>
-        <properties />
+        <properties>
+            <property name="allow-underscore"
+                      description="Allow an optional, single underscore at the beginning."
+                      value="false" />
+        </properties>
         <example>
             <![CDATA[
 class ClassName {

src/site/rst/rules/controversial.rst

@@ -92,6 +92,14 @@ Example: ::
       }
   }
 
+This rule has the following properties:
+
++-----------------------------------+---------------+---------------------------------------------------------+
+| Name                              | Default Value | Description                                             |
++===================================+===============+=========================================================+
+| allow-underscore                  | false         | Allow an optional, single underscore at the beginning.  |
++-----------------------------------+---------------+---------------------------------------------------------+
+
 CamelCaseVariableName
 =====================
 
@@ -107,6 +115,14 @@ Example: ::
       }
   }
 
+This rule has the following properties:
+
++-----------------------------------+---------------+---------------------------------------------------------+
+| Name                              | Default Value | Description                                             |
++===================================+===============+=========================================================+
+| allow-underscore                  | false         | Allow an optional, single underscore at the beginning.  |
++-----------------------------------+---------------+---------------------------------------------------------+
+
 Remark
 ======
 

src/test/php/PHPMD/Rule/Controversial/CamelCaseVariableNameTest.php

@@ -36,6 +36,7 @@ public function testRuleDoesApplyForInvariableNameWithUnderscore()
 
         $rule = new CamelCaseVariableName();
         $rule->setReport($report);
+        $rule->addProperty('allow-underscore', 'false');
         $rule->apply($this->getClass());
     }
 
@@ -51,6 +52,7 @@ public function testRuleDoesApplyForVariableNameWithCapital()
 
         $rule = new CamelCaseVariableName();
         $rule->setReport($report);
+        $rule->addProperty('allow-underscore', 'false');
         $rule->apply($this->getClass());
     }
 
@@ -65,6 +67,7 @@ public function testRuleDoesNotApplyForValidVariableName()
 
         $rule = new CamelCaseVariableName();
         $rule->setReport($report);
+        $rule->addProperty('allow-underscore', 'false');
         $rule->apply($this->getClass());
     }
 
@@ -79,6 +82,23 @@ public function testRuleDoesNotApplyForStaticVariableAccess()
 
         $rule = new CamelCaseVariableName();
         $rule->setReport($report);
+        $rule->addProperty('allow-underscore', 'false');
+        $rule->apply($this->getClass());
+    }
+
+    /**
+     * Tests that the rule does apply for a valid variable name
+     * with an underscore at the beginning when it is allowed.
+     *
+     * @return void
+     */
+    public function testRuleDoesNotApplyForValidVariableNameWithUnderscoreWhenAllowed()
+    {
+        $report = $this->getReportMock(0);
+
+        $rule = new CamelCaseVariableName();
+        $rule->setReport($report);
+        $rule->addProperty('allow-underscore', 'true');
         $rule->apply($this->getClass());
     }
 }

src/test/resources/files/Rule/Controversial/CamelCaseVariableName/testRuleDoesNotApplyForValidVariableNameWithUnderscoreWhenAllowed.php

@@ -0,0 +1,24 @@
+<?php
+/**
+ * This file is part of PHP Mess Detector.
+ *
+ * Copyright (c) Manuel Pichler <mapi@phpmd.org>.
+ * All rights reserved.
+ *
+ * Licensed under BSD License
+ * For full copyright and license information, please see the LICENSE file.
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @author Manuel Pichler <mapi@phpmd.org>
+ * @copyright Manuel Pichler. All rights reserved.
+ * @license https://opensource.org/licenses/bsd-license.php BSD License
+ * @link http://phpmd.org/
+ */
+
+class testRuleDoesNotApplyForValidVariableNameWithUnderscoreWhenAllowed
+{
+    public function validVariableNameWithUnderscoreWhenAllowed()
+    {
+        $_dataModule = 'foo';
+    }
+}