StaticPropertyFetch is an impure point

Author: ondrejmirtes

src/Analyser/ImpurePoint.php

@@ -6,7 +6,7 @@
 use PHPStan\Node\VirtualNode;
 
 /**
- * @phpstan-type ImpurePointIdentifier = 'echo'|'die'|'exit'|'propertyAssign'|'propertyAssignByRef'|'propertyUnset'|'methodCall'|'new'|'functionCall'|'include'|'require'|'print'|'eval'|'superglobal'|'yield'|'yieldFrom'|'static'|'global'|'betweenPhpTags'
+ * @phpstan-type ImpurePointIdentifier = 'echo'|'die'|'exit'|'propertyAssign'|'propertyAssignByRef'|'propertyUnset'|'methodCall'|'new'|'functionCall'|'include'|'require'|'print'|'eval'|'superglobal'|'yield'|'yieldFrom'|'static'|'global'|'betweenPhpTags'|'staticPropertyAccess'
  * @api
  * @final
  */

src/Analyser/NodeScopeResolver.php

@@ -2908,7 +2908,15 @@ static function (): void {
 		} elseif ($expr instanceof StaticPropertyFetch) {
 			$hasYield = false;
 			$throwPoints = [];
-			$impurePoints = [];
+			$impurePoints = [
+				new ImpurePoint(
+					$scope,
+					$expr,
+					'staticPropertyAccess',
+					'static property access',
+					true,
+				),
+			];
 			if ($expr->class instanceof Expr) {
 				$result = $this->processExprNode($stmt, $expr->class, $scope, $nodeCallback, $context->enterDeep());
 				$hasYield = $result->hasYield();

tests/PHPStan/Rules/Pure/PureMethodRuleTest.php

@@ -140,6 +140,14 @@ public function testRule(): void
 				'Possibly impure call to a callable in pure method PureMethod\MaybeCallableFromUnion::doFoo().',
 				330,
 			],
+			[
+				'Impure static property access in pure method PureMethod\StaticMethodAccessingStaticProperty::getA().',
+				388,
+			],
+			[
+				'Impure property assignment in pure method PureMethod\StaticMethodAssigningStaticProperty::getA().',
+				409,
+			],
 		]);
 	}
 
@@ -151,6 +159,10 @@ public function testPureConstructor(): void
 
 		$this->treatPhpDocTypesAsCertain = true;
 		$this->analyse([__DIR__ . '/data/pure-constructor.php'], [
+			[
+				'Impure static property access in pure method PureConstructor\Foo::__construct().',
+				19,
+			],
 			[
 				'Impure property assignment in pure method PureConstructor\Foo::__construct().',
 				19,

tests/PHPStan/Rules/Pure/data/pure-method.php

@@ -375,3 +375,49 @@ public function assertSth($value): void
 	}
 
 }
+
+class StaticMethodAccessingStaticProperty
+{
+	public static int $a = 0;
+
+	/**
+	 * @phpstan-pure
+	 */
+	public static function getA(): int
+	{
+		return self::$a;
+	}
+
+	/**
+	 * @phpstan-impure
+	 */
+	public static function getB(): int
+	{
+		return self::$a;
+	}
+}
+
+class StaticMethodAssigningStaticProperty
+{
+	public static int $a = 0;
+
+	/**
+	 * @phpstan-pure
+	 */
+	public static function getA(): int
+	{
+		self::$a = 1;
+
+		return 1;
+	}
+
+	/**
+	 * @phpstan-impure
+	 */
+	public static function getB(): int
+	{
+		self::$a = 1;
+
+		return 1;
+	}
+}