Bleeding edge - private method called through static::

Author: ondrejmirtes

conf/bleedingEdge.neon

@@ -25,5 +25,6 @@ parameters:
 		crossCheckInterfaces: true
 		finalByPhpDocTag: true
 		classConstants: true
+		privateStaticCall: true
 	stubFiles:
 		- ../stubs/arrayFunctions.stub

conf/config.level2.neon

@@ -9,6 +9,8 @@ parameters:
 conditionalTags:
 	PHPStan\Rules\PhpDoc\IncompatibleClassConstantPhpDocTypeRule:
 		phpstan.rules.rule: %featureToggles.classConstants%
+	PHPStan\Rules\Methods\CallPrivateMethodThroughStaticRule:
+		phpstan.rules.rule: %featureToggles.privateStaticCall%
 
 rules:
 	- PHPStan\Rules\Cast\EchoRule
@@ -54,6 +56,8 @@ services:
 			crossCheckInterfaces: %featureToggles.crossCheckInterfaces%
 		tags:
 			- phpstan.rules.rule
+	-
+		class: PHPStan\Rules\Methods\CallPrivateMethodThroughStaticRule
 	-
 		class: PHPStan\Rules\PhpDoc\IncompatibleClassConstantPhpDocTypeRule
 	-

conf/config.neon

@@ -49,6 +49,7 @@ parameters:
 		crossCheckInterfaces: false
 		finalByPhpDocTag: false
 		classConstants: false
+		privateStaticCall: false
 	fileExtensions:
 		- php
 	checkAlwaysTrueCheckTypeFunctionCall: false
@@ -227,7 +228,8 @@ parametersSchema:
 		validateOverridingMethodsInStubs: bool(),
 		crossCheckInterfaces: bool(),
 		finalByPhpDocTag: bool(),
-		classConstants: bool()
+		classConstants: bool(),
+		privateStaticCall: bool()
 	])
 	fileExtensions: listOf(string())
 	checkAlwaysTrueCheckTypeFunctionCall: bool()

src/Rules/Methods/CallPrivateMethodThroughStaticRule.php

@@ -0,0 +1,61 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Methods;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\StaticCall;
+use PhpParser\Node\Name;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @implements Rule<StaticCall>
+ */
+class CallPrivateMethodThroughStaticRule implements Rule
+{
+
+	public function getNodeType(): string
+	{
+		return StaticCall::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (!$node->name instanceof Node\Identifier) {
+			return [];
+		}
+		if (!$node->class instanceof Name) {
+			return [];
+		}
+
+		$methodName = $node->name->name;
+		$className = $node->class;
+		if ($className->toLowerString() !== 'static') {
+			return [];
+		}
+
+		$classType = $scope->resolveTypeByName($className);
+		if (!$classType->hasMethod($methodName)->yes()) {
+			return [];
+		}
+
+		$method = $classType->getMethod($methodName, $scope);
+		if (!$method->isPrivate()) {
+			return [];
+		}
+
+		if ($scope->isInClass() && $scope->getClassReflection()->isFinal()) {
+			return [];
+		}
+
+		return [
+			RuleErrorBuilder::message(sprintf(
+				'Unsafe call to private method %s::%s() through static::.',
+				$method->getDeclaringClass()->getDisplayName(),
+				$method->getName()
+			))->build(),
+		];
+	}
+
+}

tests/PHPStan/Rules/Methods/CallPrivateMethodThroughStaticRuleTest.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Methods;
+
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<CallPrivateMethodThroughStaticRule>
+ */
+class CallPrivateMethodThroughStaticRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): \PHPStan\Rules\Rule
+	{
+		return new CallPrivateMethodThroughStaticRule();
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/call-private-method-static.php'], [
+			[
+				'Unsafe call to private method CallPrivateMethodThroughStatic\Foo::doBar() through static::.',
+				12,
+			],
+		]);
+	}
+
+}

tests/PHPStan/Rules/Methods/CallStaticMethodsRuleTest.php

@@ -225,6 +225,10 @@ public function testCallStaticMethods(): void
 				328,
 				'Learn more at https://phpstan.org/user-guide/discovering-symbols',
 			],
+			[
+				'Call to an undefined static method static(CallStaticMethods\CallWithStatic)::nonexistent().',
+				344,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Methods/data/call-private-method-static.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace CallPrivateMethodThroughStatic;
+
+class Foo
+{
+
+	public function doFoo()
+	{
+		static::doFoo();
+		static::nonexistent();
+		static::doBar();
+	}
+
+	private function doBar()
+	{
+
+	}
+
+}
+
+final class Bar
+{
+
+	public function doFoo()
+	{
+		static::doFoo();
+		static::nonexistent();
+		static::doBar();
+	}
+
+	private function doBar()
+	{
+
+	}
+
+}

tests/PHPStan/Rules/Methods/data/call-static-methods.php

@@ -329,3 +329,19 @@ public function doBar(TraitWithStaticMethod $a): void
 	}
 
 }
+
+class CallWithStatic
+{
+
+	private function doFoo()
+	{
+
+	}
+
+	public function doBar()
+	{
+		static::doFoo(); // reported by different rule
+		static::nonexistent();
+	}
+
+}