Generic/UselessOverridingMethod: bail if not checking a class method

The UselessOverridingMethod is triggered when the T_FUNCTION token is
found. This token is used for regular functions and also methods.

The sniff should run only for class and trait methods (including abstract and
anonymous classes). Those are the only methods that can have a parent.
So this commit changes the sniff to bail early when dealing with a
regular functions, nested functions, interfaces methods and enum methods.

src/Standards/Generic/Sniffs/CodeAnalysis/UselessOverridingMethodSniff.php

@@ -28,6 +28,17 @@
 class UselessOverridingMethodSniff implements Sniff
 {
 
+    /**
+     * Object-Oriented scopes in which a call to parent::method() can exist.
+     *
+     * @var array<int|string, bool> Keys are the token constants, value is irrelevant.
+     */
+    private $validOOScopes = [
+        T_CLASS      => true,
+        T_ANON_CLASS => true,
+        T_TRAIT      => true,
+    ];
+
 
     /**
      * Registers the tokens that this sniff wants to listen for.
@@ -60,6 +71,14 @@ public function process(File $phpcsFile, $stackPtr)
             return;
         }
 
+        $conditions    = $token['conditions'];
+        $lastCondition = end($conditions);
+
+        // Skip functions that are not a method part of a class, anon class or trait.
+        if (isset($this->validOOScopes[$lastCondition]) === false) {
+            return;
+        }
+
         // Get function name.
         $methodName = $phpcsFile->getDeclarationName($stackPtr);
 

src/Standards/Generic/Tests/CodeAnalysis/UselessOverridingMethodUnitTest.1.inc

@@ -78,10 +78,26 @@ class Bar {
         // This should not be flagged as non-ASCII chars have changed case, making this a different method name.
         return parent::DIFFERENTcaseDifferentNonAnsiiCharÁctÊrs();
     }
+
+    public function nestedFunctionShouldBailEarly() {
+        function nestedFunctionShouldBailEarly() {
+            // Invalid code needed to ensure an error is NOT triggered and the sniff bails early when handling nested function.
+            parent::nestedFunctionShouldBailEarly();
+        }
+    }
 }
 
 abstract class AbstractFoo {
     abstract public function sniffShouldBailEarly();
+
+    public function uselessMethodInAbstractClass() {
+        parent::uselessMethodInAbstractClass();
+    }
+
+    public function usefulMethodInAbstractClass() {
+        $a = 1;
+        parent::usefulMethodInAbstractClass($a);
+    }
 }
 
 interface InterfaceFoo {
@@ -90,4 +106,45 @@ interface InterfaceFoo {
 
 trait TraitFoo {
     abstract public function sniffShouldBailEarly();
+
+    public function usefulMethodInTrait() {
+        parent::usefulMethodInTrait();
+
+        return 1;
+    }
+
+    public function uselessMethodInTrait() {
+        return parent::uselessMethodInTrait();
+    }
+}
+
+enum EnumFoo {
+    public function sniffShouldBailEarly() {
+        // Invalid code needed to ensure an error is NOT triggered and the sniff bails early when handling an enum method.
+        parent::sniffShouldBailEarly();
+    }
+}
+
+function shouldBailEarly() {
+    // Invalid code needed to ensure an error is NOT triggered and the sniff bails early when handling a regular function.
+    parent::shouldBailEarly();
+}
+
+$anon = new class extends ParentClass {
+    public function uselessOverridingMethod() {
+        parent::uselessOverridingMethod();
+    }
+
+    public function usefulOverridingMethod() {
+        $a = 10;
+        parent::usefulOverridingMethod($a);
+    }
+};
+
+function foo() {
+    $anon = new class extends ParentClass {
+        public function uselessOverridingMethod() {
+            parent::uselessOverridingMethod();
+        }
+    };
 }

src/Standards/Generic/Tests/CodeAnalysis/UselessOverridingMethodUnitTest.php

@@ -50,12 +50,16 @@ public function getWarningList($testFile='')
         switch ($testFile) {
         case 'UselessOverridingMethodUnitTest.1.inc':
             return [
-                4  => 1,
-                16 => 1,
-                38 => 1,
-                56 => 1,
-                68 => 1,
-                72 => 1,
+                4   => 1,
+                16  => 1,
+                38  => 1,
+                56  => 1,
+                68  => 1,
+                72  => 1,
+                93  => 1,
+                116 => 1,
+                134 => 1,
+                146 => 1,
             ];
         default:
             return [];