test: add failing test case for bug #11857

Author: calebdw

tests/PHPStan/Analyser/Bug11857Test.php

@@ -0,0 +1,46 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Analyser;
+
+use PHPStan\Analyser\Analyser;
+use PHPStan\Analyser\Error;
+use PHPStan\File\FileHelper;
+use PHPStan\Testing\PHPStanTestCase;
+use Throwable;
+
+class Bug11857Test extends PHPStanTestCase
+{
+
+	public function dataIntegrationTests(): iterable
+	{
+		yield [__DIR__ . '/data/bug-11857.php'];
+	}
+
+    /** @dataProvider dataIntegrationTests */
+    public function testIntegration(string $file): void
+    {
+		$this->assertNoErrors($this->runAnalyse($file));
+    }
+
+    /** @return Error[] */
+    private function runAnalyse(string $file): array
+    {
+        $file = $this->getFileHelper()->normalizePath($file);
+
+        $analyser   = self::getContainer()->getByType(Analyser::class);
+        $fileHelper = self::getContainer()->getByType(FileHelper::class);
+
+        $errors = $analyser->analyse([$file], null, null, true, null)->getErrors();
+
+        foreach ($errors as $error) {
+            $this->assertSame($fileHelper->normalizePath($file), $error->getFilePath());
+        }
+
+        return $errors;
+    }
+
+	public static function getAdditionalConfigFiles(): array
+	{
+		return [__DIR__ . '/bug-11857.neon'];
+	}
+}

tests/PHPStan/Analyser/bug-11857.neon

@@ -0,0 +1,5 @@
+services:
+	-
+		class: Bug11857\RelationDynamicMethodReturnTypeExtension
+		tags:
+			- phpstan.broker.dynamicMethodReturnTypeExtension

tests/PHPStan/Analyser/data/bug-11857.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace Bug11857;
+
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+use PhpParser\Node\Expr\MethodCall;
+
+use function PHPStan\Testing\assertType;
+
+class RelationDynamicMethodReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+    public function getClass(): string
+    {
+        return Model::class;
+    }
+
+    public function isMethodSupported(MethodReflection $methodReflection): bool
+    {
+        return $methodReflection->getName() === 'belongsTo';
+    }
+
+	public function getTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): Type {
+        $returnType = $methodReflection->getVariants()[0]->getReturnType();
+		$argType    = $scope->getType($methodCall->getArgs()[0]->value);
+		$modelClass = $argType->getClassStringObjectType()->getObjectClassNames()[0];
+
+        return new GenericObjectType($returnType->getObjectClassNames()[0], [
+			new ObjectType($modelClass),
+			$scope->getType($methodCall->var),
+		]);
+    }
+}
+
+abstract class Model
+{
+	/** @return BelongsTo<*, *> */
+	public function belongsTo(string $related): BelongsTo
+	{
+		return new BelongsTo();
+	}
+}
+
+/**
+ * @template TRelatedModel of Model
+ * @template TDeclaringModel of Model
+ */
+class BelongsTo {}
+
+class User extends Model {}
+
+class Post extends Model
+{
+	/** @return BelongsTo<User, $this> */
+	public function user(): BelongsTo
+	{
+		return $this->belongsTo(User::class);
+	}
+
+	/** @return BelongsTo<User, self> */
+	public function userSelf(): BelongsTo
+	{
+		/** @phpstan-ignore return.type */
+		return $this->belongsTo(User::class);
+	}
+}
+
+class ChildPost extends Post {}
+
+final class Comment extends Model
+{
+	// This model is final, so either of these
+	// two methods would work. It seems that
+	// PHPStan is automatically converting the
+	// `$this` to a `self` type in the user docblock,
+	// but it is not doing so likewise for the `$this`
+	// that is returned by the dynamic return extension.
+
+	/** @return BelongsTo<User, $this> */
+	public function user(): BelongsTo
+	{
+		return $this->belongsTo(User::class);
+	}
+
+	/** @return BelongsTo<User, self> */
+	public function user2(): BelongsTo
+	{
+		return $this->belongsTo(User::class);
+	}
+}
+
+function test(ChildPost $child): void
+{
+	assertType('Bug11857\BelongsTo<Bug11857\User, Bug11857\ChildPost>', $child->user());
+	// This demonstrates why `$this` is needed in non-final models
+	assertType('Bug11857\BelongsTo<Bug11857\User, Bug11857\ChildPost>', $child->userSelf());
+}