PHPUnit PHPStan extension

phpstan.php

<?php declare(strict_types = 1);

namespace Slevomat\PHPStan;

use Slevomat\TestCase;

class TestCaseDynamicReturnTypeExtension implements \PHPStan\Type\DynamicMethodReturnTypeExtension
{

	public static function getClass(): string
	{
		return TestCase::class;
	}

	public function isMethodSupported(\PHPStan\Reflection\MethodReflection $methodReflection): bool
	{
		return $methodReflection->getName() === 'createMock';
	}

	public function getTypeFromMethodCall(
		\PHPStan\Reflection\MethodReflection $methodReflection,
		\PhpParser\Node\Expr\MethodCall $methodCall,
		\PHPStan\Analyser\Scope $scope
	): \PHPStan\Type\Type
	{
		if (count($methodCall->args) === 0) {
			return $methodReflection->getReturnType();
		}

		$arg = $methodCall->args[0]->value;
		if (!($arg instanceof \PhpParser\Node\Expr\ClassConstFetch)) {
			return $methodReflection->getReturnType();
		}

		$class = $arg->class;
		if (!($class instanceof \PhpParser\Node\Name)) {
			return $methodReflection->getReturnType();
		}

		$class = (string) $class;

		if ($class === 'static') {
			return $methodReflection->getReturnType();
		}

		if ($class === 'self') {
			$class = $scope->getClass();
		}

		return new \PHPStan\Type\CommonUnionType(
			[
				new \PHPStan\Type\ObjectType($class, false),
				new \PHPStan\Type\ObjectType(\PHPUnit_Framework_MockObject_MockObject::class, false),
			],
			false
		);
	}

}