Test mixed type support

build/phpstan.neon

@@ -18,6 +18,7 @@ parameters:
 		- %rootDir%/tests/notAutoloaded/*
 		- %rootDir%/tests/PHPStan/Generics/functions.php
 		- %rootDir%/tests/PHPStan/Reflection/UnionTypesTest.php
+		- %rootDir%/tests/PHPStan/Reflection/MixedTypeTest.php
 	ignoreErrors:
 		- '#^Dynamic call to static method PHPUnit\\Framework\\\S+\(\)\.$#'
 		- '#should be contravariant with parameter \$node \(PhpParser\\Node\) of method PHPStan\\Rules\\Rule<PhpParser\\Node>::processNode\(\)$#'

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -10000,6 +10000,15 @@ public function dataNativeUnionTypes(): array
 		return $this->gatherAssertTypes(__DIR__ . '/../Reflection/data/unionTypes.php');
 	}
 
+	public function dataNativeMixedType(): array
+	{
+		if (PHP_VERSION_ID < 80000 && !self::$useStaticReflectionProvider) {
+			return [];
+		}
+
+		return $this->gatherAssertTypes(__DIR__ . '/../Reflection/data/mixedType.php');
+	}
+
 	/**
 	 * @dataProvider dataBug2574
 	 * @dataProvider dataBug2577

tests/PHPStan/Reflection/MixedTypeTest.php

@@ -0,0 +1,46 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Reflection;
+
+use NativeMixedType\Foo;
+use PhpParser\Node\Name;
+use PHPStan\Testing\TestCase;
+use PHPStan\Type\MixedType;
+
+class MixedTypeTest extends TestCase
+{
+
+	public function testMixedType(): void
+	{
+		if (PHP_VERSION_ID < 80000 && !self::$useStaticReflectionProvider) {
+			$this->markTestSkipped('Test requires PHP 8.0');
+		}
+
+		$reflectionProvider = $this->createBroker();
+		$class = $reflectionProvider->getClass(Foo::class);
+		$propertyType = $class->getNativeProperty('fooProp')->getNativeType();
+		$this->assertInstanceOf(MixedType::class, $propertyType);
+		$this->assertTrue($propertyType->isExplicitMixed());
+
+		$method = $class->getNativeMethod('doFoo');
+		$methodVariant = ParametersAcceptorSelector::selectSingle($method->getVariants());
+		$methodReturnType = $methodVariant->getReturnType();
+		$this->assertInstanceOf(MixedType::class, $methodReturnType);
+		$this->assertTrue($methodReturnType->isExplicitMixed());
+
+		$methodParameterType = $methodVariant->getParameters()[0]->getType();
+		$this->assertInstanceOf(MixedType::class, $methodParameterType);
+		$this->assertTrue($methodParameterType->isExplicitMixed());
+
+		$function = $reflectionProvider->getFunction(new Name('NativeMixedType\doFoo'), null);
+		$functionVariant = ParametersAcceptorSelector::selectSingle($function->getVariants());
+		$functionReturnType = $functionVariant->getReturnType();
+		$this->assertInstanceOf(MixedType::class, $functionReturnType);
+		$this->assertTrue($functionReturnType->isExplicitMixed());
+
+		$functionParameterType = $functionVariant->getParameters()[0]->getType();
+		$this->assertInstanceOf(MixedType::class, $functionParameterType);
+		$this->assertTrue($functionParameterType->isExplicitMixed());
+	}
+
+}

tests/PHPStan/Reflection/data/mixedType.php

@@ -0,0 +1,42 @@
+<?php // lint >= 8.0
+
+namespace NativeMixedType;
+
+use function PHPStan\Analyser\assertType;
+
+class Foo
+{
+
+	public mixed $fooProp;
+
+	public function doFoo(mixed $foo): mixed
+	{
+		assertType('mixed', $foo);
+		assertType('mixed', $this->fooProp);
+	}
+
+}
+
+class Bar
+{
+
+}
+
+function doFoo(mixed $foo): mixed
+{
+	assertType('mixed', $foo);
+}
+
+function (Foo $foo): void {
+	assertType('mixed', $foo->fooProp);
+	assertType('mixed', $foo->doFoo(1));
+	assertType('mixed', doFoo(1));
+};
+
+function (): void {
+	$f = function (mixed $foo): mixed {
+		assertType('mixed', $foo);
+	};
+
+	assertType('mixed', $f(1));
+};