Fix #179 - Nette\Application\UI\Multiplier factory can return null

extension.neon

@@ -7,7 +7,6 @@ parameters:
 	stubFiles:
 		- stubs/Application/Routers/RouteList.stub
 		- stubs/Application/UI/Component.stub
-		- stubs/Application/UI/Multiplier.stub
 		- stubs/Application/UI/Presenter.stub
 		- stubs/Caching/Cache.stub
 		- stubs/ComponentModel/Component.stub
@@ -52,6 +51,11 @@ parameters:
 			- forward
 
 services:
+	-
+		class: PHPStan\Stubs\Nette\Application\StubFilesExtensionLoader
+		tags:
+			- phpstan.stubFilesExtension
+
 	-
 		class: PHPStan\Reflection\Nette\HtmlClassReflectionExtension
 		tags:

src/Stubs/Nette/Application/StubFilesExtensionLoader.php

@@ -0,0 +1,38 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Stubs\Nette\Application;
+
+use Composer\InstalledVersions;
+use OutOfBoundsException;
+use PHPStan\PhpDoc\StubFilesExtension;
+use function class_exists;
+use function dirname;
+use function version_compare;
+
+class StubFilesExtensionLoader implements StubFilesExtension
+{
+
+	public function getFiles(): array
+	{
+		$path = dirname(dirname(dirname(dirname(__DIR__)))) . '/stubs';
+
+		try {
+			$applicationVersion = class_exists(InstalledVersions::class)
+				? InstalledVersions::getVersion('nette/application')
+				: null;
+		} catch (OutOfBoundsException $e) {
+			$applicationVersion = null;
+		}
+
+		$files = [];
+
+		if ($applicationVersion !== null && version_compare($applicationVersion, '3.2.5', '>=')) {
+			$files[] = $path . '/Application/UI/Multiplier1.stub';
+		} else {
+			$files[] = $path . '/Application/UI/Multiplier.stub';
+		}
+
+		return $files;
+	}
+
+}

stubs/Application/UI/Multiplier1.stub

@@ -0,0 +1,19 @@
+<?php
+
+namespace Nette\Application\UI;
+
+/**
+ * @template T of \Nette\ComponentModel\IComponent
+ */
+final class Multiplier extends Component
+{
+    /**
+     * @param callable(string, self<T>) : (T|null) $factory
+     */
+    public function __construct(callable $factory);
+
+    /**
+     * @return T|null
+     */
+    protected function createComponent(string $name): ?\Nette\ComponentModel\IComponent;
+}

tests/Type/Nette/MultiplierTest.php

@@ -2,14 +2,30 @@
 
 namespace PHPStan\Type\Nette;
 
+use Composer\InstalledVersions;
+use OutOfBoundsException;
 use PHPStan\Testing\TypeInferenceTestCase;
+use function class_exists;
+use function version_compare;
 
 class MultiplierTest extends TypeInferenceTestCase
 {
 
 	public function dataFileAsserts(): iterable
 	{
-		yield from self::gatherAssertTypes(__DIR__ . '/data/multiplier.php');
+		try {
+			$applicationVersion = class_exists(InstalledVersions::class)
+				? InstalledVersions::getVersion('nette/application')
+				: null;
+		} catch (OutOfBoundsException $e) {
+			$applicationVersion = null;
+		}
+
+		if ($applicationVersion !== null && version_compare($applicationVersion, '3.2.5', '>=')) {
+			yield from self::gatherAssertTypes(__DIR__ . '/data/multiplierApplication325.php');
+		} else {
+			yield from self::gatherAssertTypes(__DIR__ . '/data/multiplier.php');
+		}
 	}
 
 	/**

tests/Type/Nette/data/multiplierApplication325.php

@@ -0,0 +1,25 @@
+<?php declare(strict_types = 1);
+
+use Nette\Application\UI\Form;
+use Nette\Application\UI\Multiplier;
+
+use function PHPStan\Testing\assertType;
+
+/** @var Multiplier<Form> $multiplier */
+$multiplier = new Multiplier(function (string $name): ?Form {
+	if($name === 'foo') {
+		return new Form();
+	} else {
+		return null;
+	}
+});
+
+assertType('Nette\Application\UI\Multiplier<Nette\Application\UI\Form>', $multiplier);
+
+$form = $multiplier->createComponent('foo');
+
+assertType(Form::class . '|null', $form);
+
+$notSupportedForm = $multiplier->createComponent('notSupported');
+
+assertType(Form::class . '|null', $notSupportedForm);