Support getting reflection of an anonymous function

src/Reflection/Php/ClosureInvokeMethodReflection.php

@@ -0,0 +1,106 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Reflection\Php;
+
+use PHPStan\Reflection\ClassMemberReflection;
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Reflection\FunctionVariant;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\TrinaryLogic;
+use PHPStan\Type\ClosureType;
+use PHPStan\Type\Type;
+
+final class ClosureInvokeMethodReflection implements MethodReflection
+{
+
+	/** @var MethodReflection */
+	private $nativeMethodReflection;
+
+	/** @var ClosureType */
+	private $closureType;
+
+	public function __construct(MethodReflection $nativeMethodReflection, ClosureType $closureType)
+	{
+		$this->nativeMethodReflection = $nativeMethodReflection;
+		$this->closureType = $closureType;
+	}
+
+	public function getDeclaringClass(): ClassReflection
+	{
+		return $this->nativeMethodReflection->getDeclaringClass();
+	}
+
+	public function isStatic(): bool
+	{
+		return $this->nativeMethodReflection->isStatic();
+	}
+
+	public function isPrivate(): bool
+	{
+		return $this->nativeMethodReflection->isPrivate();
+	}
+
+	public function isPublic(): bool
+	{
+		return $this->nativeMethodReflection->isPublic();
+	}
+
+	public function getDocComment(): ?string
+	{
+		return $this->nativeMethodReflection->getDocComment();
+	}
+
+	public function getName(): string
+	{
+		return $this->nativeMethodReflection->getName();
+	}
+
+	public function getPrototype(): ClassMemberReflection
+	{
+		return $this->nativeMethodReflection->getPrototype();
+	}
+
+	public function getVariants(): array
+	{
+		return [
+			new FunctionVariant(
+				$this->closureType->getTemplateTypeMap(),
+				$this->closureType->getResolvedTemplateTypeMap(),
+				$this->closureType->getParameters(),
+				$this->closureType->isVariadic(),
+				$this->closureType->getReturnType()
+			),
+		];
+	}
+
+	public function isDeprecated(): TrinaryLogic
+	{
+		return $this->nativeMethodReflection->isDeprecated();
+	}
+
+	public function getDeprecatedDescription(): ?string
+	{
+		return $this->nativeMethodReflection->getDeprecatedDescription();
+	}
+
+	public function isFinal(): TrinaryLogic
+	{
+		return $this->nativeMethodReflection->isFinal();
+	}
+
+	public function isInternal(): TrinaryLogic
+	{
+		return $this->nativeMethodReflection->isInternal();
+	}
+
+	public function getThrowType(): ?Type
+	{
+		return $this->nativeMethodReflection->getThrowType();
+	}
+
+	public function hasSideEffects(): TrinaryLogic
+	{
+		return $this->nativeMethodReflection->hasSideEffects();
+	}
+
+}

src/Type/ClosureType.php

@@ -10,6 +10,7 @@
 use PHPStan\Reflection\ParameterReflection;
 use PHPStan\Reflection\ParametersAcceptor;
 use PHPStan\Reflection\Php\ClosureCallMethodReflection;
+use PHPStan\Reflection\Php\ClosureInvokeMethodReflection;
 use PHPStan\Reflection\PropertyReflection;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Constant\ConstantArrayType;
@@ -167,6 +168,13 @@ public function getMethod(string $methodName, ClassMemberAccessAnswerer $scope):
 			);
 		}
 
+		if ($methodName === '__invoke') {
+			return new ClosureInvokeMethodReflection(
+				$this->objectType->getMethod($methodName, $scope),
+				$this
+			);
+		}
+
 		return $this->objectType->getMethod($methodName, $scope);
 	}