From dffd2c2351e5fc5d22b752bf3b8be84bf1708f71 Mon Sep 17 00:00:00 2001
From: Ondrej Mirtes <ondrej@mirtes.cz>
Date: Tue, 20 Jul 2021 17:21:53 +0200
Subject: [PATCH] Bleeding edge - check classes extending `@final` classes

---
 conf/bleedingEdge.neon                        |  1 +
 conf/config.level0.neon                       |  8 ++++++-
 conf/config.neon                              |  4 +++-
 .../ExistingClassInClassExtendsRule.php       | 12 +++++++++-
 .../ExistingClassInClassExtendsRuleTest.php   | 17 ++++++++++++-
 .../Classes/data/extends-final-by-tag.php     | 24 +++++++++++++++++++
 6 files changed, 62 insertions(+), 4 deletions(-)
 create mode 100644 tests/PHPStan/Rules/Classes/data/extends-final-by-tag.php

diff --git a/conf/bleedingEdge.neon b/conf/bleedingEdge.neon
index 1742270d01..2c4bc61dfc 100644
--- a/conf/bleedingEdge.neon
+++ b/conf/bleedingEdge.neon
@@ -23,5 +23,6 @@ parameters:
 		neverInGenericReturnType: true
 		validateOverridingMethodsInStubs: true
 		crossCheckInterfaces: true
+		finalByPhpDocTag: true
 	stubFiles:
 		- ../stubs/arrayFunctions.stub
diff --git a/conf/config.level0.neon b/conf/config.level0.neon
index 5df0e46ec7..e13224c8d9 100644
--- a/conf/config.level0.neon
+++ b/conf/config.level0.neon
@@ -42,7 +42,6 @@ rules:
 	- PHPStan\Rules\Classes\DuplicateDeclarationRule
 	- PHPStan\Rules\Classes\ExistingClassesInClassImplementsRule
 	- PHPStan\Rules\Classes\ExistingClassesInInterfaceExtendsRule
-	- PHPStan\Rules\Classes\ExistingClassInClassExtendsRule
 	- PHPStan\Rules\Classes\ExistingClassInTraitUseRule
 	- PHPStan\Rules\Classes\InstantiationRule
 	- PHPStan\Rules\Classes\InvalidPromotedPropertiesRule
@@ -98,6 +97,13 @@ services:
 	-
 		class: PHPStan\Rules\Api\PhpStanNamespaceIn3rdPartyPackageRule
 
+	-
+		class: PHPStan\Rules\Classes\ExistingClassInClassExtendsRule
+		arguments:
+			checkFinalByPhpDocTag: %featureToggles.finalByPhpDocTag%
+		tags:
+			- phpstan.rules.rule
+
 	-
 		class: PHPStan\Rules\Classes\ExistingClassInInstanceOfRule
 		tags:
diff --git a/conf/config.neon b/conf/config.neon
index c87e525cce..2ffb0dd6be 100644
--- a/conf/config.neon
+++ b/conf/config.neon
@@ -46,6 +46,7 @@ parameters:
 		neverInGenericReturnType: false
 		validateOverridingMethodsInStubs: false
 		crossCheckInterfaces: false
+		finalByPhpDocTag: false
 	fileExtensions:
 		- php
 	checkAlwaysTrueCheckTypeFunctionCall: false
@@ -219,7 +220,8 @@ parametersSchema:
 		deepInspectTypes: bool(),
 		neverInGenericReturnType: bool(),
 		validateOverridingMethodsInStubs: bool(),
-		crossCheckInterfaces: bool()
+		crossCheckInterfaces: bool(),
+		finalByPhpDocTag: bool()
 	])
 	fileExtensions: listOf(string())
 	checkAlwaysTrueCheckTypeFunctionCall: bool()
diff --git a/src/Rules/Classes/ExistingClassInClassExtendsRule.php b/src/Rules/Classes/ExistingClassInClassExtendsRule.php
index 53e049e9d1..c500cc1ee0 100644
--- a/src/Rules/Classes/ExistingClassInClassExtendsRule.php
+++ b/src/Rules/Classes/ExistingClassInClassExtendsRule.php
@@ -19,13 +19,17 @@ class ExistingClassInClassExtendsRule implements \PHPStan\Rules\Rule
 
 	private ReflectionProvider $reflectionProvider;
 
+	private bool $checkFinalByPhpDocTag;
+
 	public function __construct(
 		ClassCaseSensitivityCheck $classCaseSensitivityCheck,
-		ReflectionProvider $reflectionProvider
+		ReflectionProvider $reflectionProvider,
+		bool $checkFinalByPhpDocTag = false
 	)
 	{
 		$this->classCaseSensitivityCheck = $classCaseSensitivityCheck;
 		$this->reflectionProvider = $reflectionProvider;
+		$this->checkFinalByPhpDocTag = $checkFinalByPhpDocTag;
 	}
 
 	public function getNodeType(): string
@@ -72,6 +76,12 @@ public function processNode(Node $node, Scope $scope): array
 					$currentClassName !== null ? sprintf('Class %s', $currentClassName) : 'Anonymous class',
 					$extendedClassName
 				))->nonIgnorable()->build();
+			} elseif ($this->checkFinalByPhpDocTag && $reflection->isFinal()) {
+				$messages[] = RuleErrorBuilder::message(sprintf(
+					'%s extends @final class %s.',
+					$currentClassName !== null ? sprintf('Class %s', $currentClassName) : 'Anonymous class',
+					$extendedClassName
+				))->build();
 			}
 		}
 
diff --git a/tests/PHPStan/Rules/Classes/ExistingClassInClassExtendsRuleTest.php b/tests/PHPStan/Rules/Classes/ExistingClassInClassExtendsRuleTest.php
index 836894513f..43c2b2242d 100644
--- a/tests/PHPStan/Rules/Classes/ExistingClassInClassExtendsRuleTest.php
+++ b/tests/PHPStan/Rules/Classes/ExistingClassInClassExtendsRuleTest.php
@@ -16,7 +16,8 @@ protected function getRule(): Rule
 		$broker = $this->createReflectionProvider();
 		return new ExistingClassInClassExtendsRule(
 			new ClassCaseSensitivityCheck($broker),
-			$broker
+			$broker,
+			true
 		);
 	}
 
@@ -27,6 +28,10 @@ public function testRule(): void
 				'Class ExtendsImplements\Foo referenced with incorrect case: ExtendsImplements\FOO.',
 				15,
 			],
+			[
+				'Class ExtendsImplements\ExtendsFinalWithAnnotation extends @final class ExtendsImplements\FinalWithAnnotation.',
+				43,
+			],
 		]);
 	}
 
@@ -61,4 +66,14 @@ public function testRuleExtendsError(): void
 		]);
 	}
 
+	public function testFinalByTag(): void
+	{
+		$this->analyse([__DIR__ . '/data/extends-final-by-tag.php'], [
+			[
+				'Class ExtendsFinalByTag\Bar2 extends @final class ExtendsFinalByTag\Bar.',
+				21,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Classes/data/extends-final-by-tag.php b/tests/PHPStan/Rules/Classes/data/extends-final-by-tag.php
new file mode 100644
index 0000000000..501c6e8f00
--- /dev/null
+++ b/tests/PHPStan/Rules/Classes/data/extends-final-by-tag.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace ExtendsFinalByTag;
+
+class Foo
+{
+
+}
+
+/** @final */
+class Bar
+{
+
+}
+
+class Foo2 extends Foo
+{
+
+}
+
+class Bar2 extends Bar
+{
+
+}