Reflection::getCases

Author: janedbal

README.md

@@ -90,8 +90,8 @@ parameters:
 ## Generic usage providers:
 
 #### Reflection:
-- Any constant or method accessed via `ReflectionClass` is detected as used
-  - e.g. `$reflection->getConstructor()`, `$reflection->getConstant('NAME')`, `$reflection->getMethods()`, ...
+- Any enum, constant or method accessed via `ReflectionClass` is detected as used
+  - e.g. `$reflection->getConstructor()`, `$reflection->getConstant('NAME')`, `$reflection->getMethods()`, `$reflection->getCases()`...
 
 #### Vendor:
 - Any overridden method that originates in `vendor` is not reported as dead

src/Provider/ReflectionUsageProvider.php

@@ -17,6 +17,8 @@
 use ShipMonk\PHPStan\DeadCode\Graph\ClassMemberUsage;
 use ShipMonk\PHPStan\DeadCode\Graph\ClassMethodRef;
 use ShipMonk\PHPStan\DeadCode\Graph\ClassMethodUsage;
+use ShipMonk\PHPStan\DeadCode\Graph\EnumCaseRef;
+use ShipMonk\PHPStan\DeadCode\Graph\EnumCaseUsage;
 use ShipMonk\PHPStan\DeadCode\Graph\UsageOrigin;
 use function array_key_first;
 use function count;
@@ -63,6 +65,7 @@ private function processMethodCall(
 
         $usedConstants = [];
         $usedMethods = [];
+        $usedEnumCases = [];
 
         foreach ($methodNames as $methodName) {
             foreach ($callerType->getObjectClassReflections() as $reflection) {
@@ -86,6 +89,10 @@ private function processMethodCall(
                             ...$usedMethods,
                             ...$this->extractMethodsUsedByReflection($genericClassName, $methodName, $node->getArgs(), $node, $scope),
                         ];
+                        $usedEnumCases = [
+                            ...$usedEnumCases,
+                            ...$this->extractEnumCasesUsedByReflection($genericClassName, $methodName, $node->getArgs(), $node, $scope),
+                        ];
                     }
                 }
             }
@@ -94,6 +101,7 @@ private function processMethodCall(
         return [
             ...$usedConstants,
             ...$usedMethods,
+            ...$usedEnumCases,
         ];
     }
 
@@ -126,6 +134,35 @@ private function extractConstantsUsedByReflection(
         return $usedConstants;
     }
 
+    /**
+     * @param array<Arg> $args
+     * @return list<EnumCaseUsage>
+     */
+    private function extractEnumCasesUsedByReflection(
+        ?string $genericClassName,
+        string $methodName,
+        array $args,
+        Node $node,
+        Scope $scope
+    ): array
+    {
+        $usedConstants = [];
+
+        if ($methodName === 'getCases') {
+            $usedConstants[] = $this->createEnumCaseUsage($node, $scope, $genericClassName, null);
+        }
+
+        if (($methodName === 'getCase') && count($args) === 1) {
+            $firstArg = $args[array_key_first($args)];
+
+            foreach ($scope->getType($firstArg->value)->getConstantStrings() as $constantString) {
+                $usedConstants[] = $this->createEnumCaseUsage($node, $scope, $genericClassName, $constantString->getValue());
+            }
+        }
+
+        return $usedConstants;
+    }
+
     /**
      * @param array<Arg> $args
      * @return list<ClassMethodUsage>
@@ -202,6 +239,22 @@ private function createConstantUsage(
         );
     }
 
+    private function createEnumCaseUsage(
+        Node $node,
+        Scope $scope,
+        ?string $className,
+        ?string $enumCaseName
+    ): EnumCaseUsage
+    {
+        return new EnumCaseUsage(
+            UsageOrigin::createRegular($node, $scope),
+            new EnumCaseRef(
+                $className,
+                $enumCaseName,
+            ),
+        );
+    }
+
     private function createMethodUsage(
         Node $node,
         Scope $scope,

tests/Rule/DeadCodeRuleTest.php

@@ -756,6 +756,7 @@ public static function provideFiles(): Traversable
         // providers
         yield 'provider-vendor' => [__DIR__ . '/data/providers/vendor.php'];
         yield 'provider-reflection' => [__DIR__ . '/data/providers/reflection.php', self::requiresPhp(8_01_00)];
+        yield 'provider-reflection-enums' => [__DIR__ . '/data/providers/reflection-enums.php', self::requiresPhp(8_01_00)];
         yield 'provider-reflection-no-t' => [__DIR__ . '/data/providers/reflection-no-generics.php'];
         yield 'provider-symfony' => [__DIR__ . '/data/providers/symfony.php', self::requiresPhp(8_00_00)];
         yield 'provider-symfony-7.1' => [__DIR__ . '/data/providers/symfony-gte71.php', self::requiresPhp(8_00_00) && self::requiresPackage('symfony/dependency-injection', '>= 7.1')];

tests/Rule/data/providers/reflection-enums.php

@@ -0,0 +1,29 @@
+<?php declare(strict_types = 1);
+
+namespace ReflectionEnums;
+
+use PHPUnit\Framework\TestCase;
+use ShipMonk\PHPStan\DeadCode\Rule\RuleTestCase;
+
+enum MyEnum1: string
+{
+    case One = 'one';
+    case Two = 'two';
+}
+
+enum MyEnum2: int
+{
+    case One = 1;
+    case Two = 2; // error: Unused ReflectionEnums\MyEnum2::Two
+}
+
+
+function test() {
+
+    $reflection1 = new \ReflectionEnum(MyEnum1::class);
+    $reflection1->getCases();
+
+    $reflection2 = new \ReflectionEnum(MyEnum2::class);
+    $reflection2->getCase('One');
+
+}