Allow __debugInfo() in enums on PHP 8.6+

Closes phpstan/phpstan#15368

Author: Amoifr

src/Php/PhpVersions.php

@@ -193,6 +193,11 @@ public function supportsDeprecatedTraits(): TrinaryLogic
 		return IntegerRangeType::fromInterval(80500, null)->isSuperTypeOf($this->phpVersions)->result;
 	}
 
+	public function supportsDebugInfoOnEnums(): TrinaryLogic
+	{
+		return IntegerRangeType::fromInterval(80600, null)->isSuperTypeOf($this->phpVersions)->result;
+	}
+
 	public function arrayFunctionsReturnNullWithNonArray(): TrinaryLogic
 	{
 		return IntegerRangeType::fromInterval(null, 79999)->isSuperTypeOf($this->phpVersions)->result;

src/Rules/Classes/EnumSanityRule.php

@@ -80,7 +80,10 @@ public function processNode(Node $node, Scope $scope): array
 						->line($methodNode->getStartLine())
 						->nonIgnorable()
 						->build();
-				} elseif (!array_key_exists($lowercasedMethodName, self::ALLOWED_MAGIC_METHODS)) {
+				} elseif (
+					!array_key_exists($lowercasedMethodName, self::ALLOWED_MAGIC_METHODS)
+					&& !($lowercasedMethodName === '__debuginfo' && $scope->getPhpVersion()->supportsDebugInfoOnEnums()->yes())
+				) {
 					$errors[] = RuleErrorBuilder::message(sprintf(
 						'Enum %s contains magic method %s().',
 						$classReflection->getDisplayName(),

tests/PHPStan/Rules/Classes/EnumSanityRuleTest.php

@@ -190,4 +190,23 @@ public function testBug11891(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.1.0')]
+	public function testDebugInfoPhpVersions(): void
+	{
+		$errors = [
+			[
+				'Enum EnumDebugInfoPhpVersions\\UnsupportedInBranch contains magic method __debugInfo().',
+				18,
+			],
+		];
+		if (PHP_VERSION_ID < 80600) {
+			$errors[] = [
+				'Enum EnumDebugInfoPhpVersions\\DependsOnPhpVersion contains magic method __debugInfo().',
+				27,
+			];
+		}
+
+		$this->analyse([__DIR__ . '/data/enum-debug-info-php-versions.php'], $errors);
+	}
+
 }

tests/PHPStan/Rules/Classes/data/enum-debug-info-php-versions.php

@@ -0,0 +1,31 @@
+<?php // lint >= 8.1
+
+namespace EnumDebugInfoPhpVersions;
+
+if (PHP_VERSION_ID >= 80600) {
+	enum SupportedInBranch
+	{
+		public function __debugInfo(): array
+		{
+			return [];
+		}
+	}
+}
+
+if (PHP_VERSION_ID < 80600) {
+	enum UnsupportedInBranch
+	{
+		public function __debugInfo(): array
+		{
+			return [];
+		}
+	}
+}
+
+enum DependsOnPhpVersion
+{
+	public function __debugInfo(): array
+	{
+		return [];
+	}
+}