forbidXxxOnMixed: more generic detection of unknown caller (#149)

Author: janedbal

src/Rule/ForbidFetchOnMixedRule.php

@@ -11,7 +11,7 @@
 use PhpParser\PrettyPrinter\Standard;
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
-use PHPStan\Type\MixedType;
+use PHPStan\Type\TypeUtils;
 use function get_class;
 use function sprintf;
 
@@ -66,9 +66,9 @@ private function processFetch(Node $node, Scope $scope): array
             return [];
         }
 
-        $callerType = $scope->getType($caller);
+        $callerType = TypeUtils::toBenevolentUnion($scope->getType($caller));
 
-        if ($callerType instanceof MixedType) {
+        if ($callerType->getObjectTypeOrClassStringObjectType()->getObjectClassNames() === []) {
             $name = $node->name;
             $property = $name instanceof Identifier
                 ? $this->printer->prettyPrint([$name])

src/Rule/ForbidMethodCallOnMixedRule.php

@@ -12,7 +12,7 @@
 use PhpParser\PrettyPrinter\Standard;
 use PHPStan\Analyser\Scope;
 use PHPStan\Rules\Rule;
-use PHPStan\Type\MixedType;
+use PHPStan\Type\TypeUtils;
 use function get_class;
 use function sprintf;
 
@@ -67,9 +67,9 @@ private function checkCall(CallLike $node, Scope $scope): array
             return [];
         }
 
-        $callerType = $scope->getType($caller);
+        $callerType = TypeUtils::toBenevolentUnion($scope->getType($caller));
 
-        if ($callerType instanceof MixedType) {
+        if ($callerType->getObjectTypeOrClassStringObjectType()->getObjectClassNames() === []) {
             $name = $node->name;
             $method = $name instanceof Identifier ? $this->printer->prettyPrint([$name]) : $this->printer->prettyPrintExpr($name);
 

tests/Rule/data/ForbidFetchOnMixedRuleTest/code.php

@@ -9,14 +9,30 @@ class Foo {
     public static ?int $staticProperty = null;
 }
 
-$fn = function (mixed $mixed, $unknown, array $array, ReflectionClass $reflection) {
+$fn = function (mixed $mixed, $unknown, string $string, array $array, ReflectionClass $reflection, ?Foo $fooOrNull) {
     (new Foo)->property;
     Foo::$staticProperty;
 
+    /** @var class-string $classString */
+    $classString = '';
+    $classString::$staticProperty; // error: Property fetch ::$staticProperty is prohibited on unknown type ($classString)
+
+    /** @var class-string<Foo> $classString2 */
+    $classString2 = '';
+    $classString2::$staticProperty;
+
+    $string::$staticProperty; // error: Property fetch ::$staticProperty is prohibited on unknown type ($string)
+
     $mixed->fetch1; // error: Property fetch ->fetch1 is prohibited on unknown type ($mixed)
     $mixed::$fetch1; // error: Property fetch ::$fetch1 is prohibited on unknown type ($mixed)
     $unknown->fetch2; // error: Property fetch ->fetch2 is prohibited on unknown type ($unknown)
     $unknown::$fetch2; // error: Property fetch ::$fetch2 is prohibited on unknown type ($unknown)
     $array[0]->fetch3; // error: Property fetch ->fetch3 is prohibited on unknown type ($array[0])
-    $reflection->newInstance()->fetch4;
+
+    $fooOrNull->property;
+    $fooOrNull?->property;
+
+    $reflection->newInstance()->property; // error: Property fetch ->property is prohibited on unknown type ($reflection->newInstance())
+    /** @var ReflectionClass<Foo> $reflection */
+    $reflection->newInstance()->property;
 };

tests/Rule/data/ForbidMethodCallOnMixedRule/code.php

@@ -9,20 +9,39 @@ public function method() {}
     public static function staticMethod() {}
 }
 
-$fn = function (mixed $mixed, $unknown, array $array, ReflectionClass $reflection) {
+$fn = function (mixed $mixed, $unknown, array $array, string $string, ?Foo $fooOrNull, ReflectionClass $reflection) {
 
     $foo = new Foo();
     $foo->method();
     $foo?->method();
     Foo::staticMethod();
     $foo::staticMethod();
 
+    $fooOrNull->method();
+    $fooOrNull?->method();
+    $fooOrNull->staticMethod();
+    $fooOrNull?->staticMethod();
+
+    /** @var class-string $classString */
+    $classString = '';
+    $classString::staticMethod(); // error: Method call ::staticMethod() is prohibited on unknown type ($classString)
+
+    /** @var class-string<Foo> $classString2 */
+    $classString2 = '';
+    $classString2::staticMethod();
+
+    $string::staticMethod(); // error: Method call ::staticMethod() is prohibited on unknown type ($string)
+
     $mixed->call1(); // error: Method call ->call1() is prohibited on unknown type ($mixed)
     $mixed?->call1(); // error: Method call ->call1() is prohibited on unknown type ($mixed)
     $mixed::call1(); // error: Method call ::call1() is prohibited on unknown type ($mixed)
     $unknown->call2(); // error: Method call ->call2() is prohibited on unknown type ($unknown)
     $unknown?->call2(); // error: Method call ->call2() is prohibited on unknown type ($unknown)
     $unknown::call2(); // error: Method call ::call2() is prohibited on unknown type ($unknown)
     $array[0]->call3(); // error: Method call ->call3() is prohibited on unknown type ($array[0])
-    $reflection->newInstance()->call4();
+
+
+    $reflection->newInstance()->method(); // error: Method call ->method() is prohibited on unknown type ($reflection->newInstance())
+    /** @var ReflectionClass<Foo> $reflection */
+    $reflection->newInstance()->method();
 };