Nullsafe operator breaks route cache

[pelomedusa]

• Laravel Version: 8.61.0
• PHP Version: 8.0.10
• Database Driver & Version: /

Description:

Using the nullsafe operator in a route file will break the route cache.

Steps To Reproduce:

Issue is reproduced here:
https://github.com/pelomedusa/laravel-8-nullsafe-operator-bug

Reproduce by following these steps:

• Create a new laravel app

 laravel new myapp
 cd myapp

• Edit the routes/web.php file with a nullsafe operator, ie:

Route::get('/', function () {
  $example = null;
  $bug = $example?->test;
  return view('welcome');
});

• Generate a route cache and serve:

php artisan route:cache
php artisan serve

• Go to http://localhost:8000 and you will get the following error

[2021-09-22 08:18:30] local.ERROR: syntax error, unexpected fully qualified name "\test", expecting identifier or variable or "{" or "$" {"exception":"[object] (ParseError(code: 0): syntax error, unexpected fully qualified name \"\\test\", expecting identifier or variable or \"{\" or \"$\" at closure://function () {
\t$example = null;
\t$bug = $example?->\\test;
    return \\view('welcome');
}:4)
[stacktrace]
#0 [internal function]: Opis\\Closure\\SerializableClosure->unserialize()
#1 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/RouteSignatureParameters.php(22): unserialize()
#2 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Route.php(513): Illuminate\\Routing\\RouteSignatureParameters::fromAction()
#3 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/ImplicitRouteBinding.php(25): Illuminate\\Routing\\Route->signatureParameters()
#4 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Router.php(833): Illuminate\\Routing\\ImplicitRouteBinding::resolveForRoute()
#5 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Middleware/SubstituteBindings.php(41): Illuminate\\Routing\\Router->substituteImplicitBindings()
#6 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Routing\\Middleware\\SubstituteBindings->handle()
#7 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/VerifyCsrfToken.php(78): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#8 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\VerifyCsrfToken->handle()
#9 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/View/Middleware/ShareErrorsFromSession.php(49): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#10 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\View\\Middleware\\ShareErrorsFromSession->handle()
#11 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(121): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#12 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(64): Illuminate\\Session\\Middleware\\StartSession->handleStatefulRequest()
#13 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Session\\Middleware\\StartSession->handle()
#14 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/AddQueuedCookiesToResponse.php(37): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#15 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse->handle()
#16 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/EncryptCookies.php(67): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#17 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Cookie\\Middleware\\EncryptCookies->handle()
#18 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(103): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#19 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Router.php(697): Illuminate\\Pipeline\\Pipeline->then()
#20 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Router.php(672): Illuminate\\Routing\\Router->runRouteWithinStack()
#21 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Router.php(636): Illuminate\\Routing\\Router->runRoute()
#22 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Routing/Router.php(625): Illuminate\\Routing\\Router->dispatchToRoute()
#23 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(166): Illuminate\\Routing\\Router->dispatch()
#24 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(128): Illuminate\\Foundation\\Http\\Kernel->Illuminate\\Foundation\\Http\\{closure}()
#25 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#26 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ConvertEmptyStringsToNull.php(31): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#27 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\ConvertEmptyStringsToNull->handle()
#28 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#29 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TrimStrings.php(40): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#30 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\TrimStrings->handle()
#31 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ValidatePostSize.php(27): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#32 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize->handle()
#33 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/PreventRequestsDuringMaintenance.php(86): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#34 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Foundation\\Http\\Middleware\\PreventRequestsDuringMaintenance->handle()
#35 /tmp/laravel-test/bugtest/vendor/fruitcake/laravel-cors/src/HandleCors.php(38): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#36 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Fruitcake\\Cors\\HandleCors->handle()
#37 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Http/Middleware/TrustProxies.php(39): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#38 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(167): Illuminate\\Http\\Middleware\\TrustProxies->handle()
#39 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(103): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}()
#40 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(141): Illuminate\\Pipeline\\Pipeline->then()
#41 /tmp/laravel-test/bugtest/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(110): Illuminate\\Foundation\\Http\\Kernel->sendRequestThroughRouter()
#42 /tmp/laravel-test/bugtest/public/index.php(52): Illuminate\\Foundation\\Http\\Kernel->handle()
#43 /tmp/laravel-test/bugtest/server.php(21): require_once('...')
#44 {main}
"} 

[derekmd]

Next Laravel release will be switching the "opis/closure" package with a new fork laravel/serializable-closure (#38801).

The "opis/closure" package's test suite has one unit test for ReflectionClosure converting a nullsafe function to a string (https://github.com/opis/closure/blob/e7254e8f2a524ae05b1e0bcb1207ac0267385eaa/tests/ReflectionClosure6Test.php#L58-L64) but I don't see a full integration test on SerializableClosure to unserialize and actually run a nullsafe'd closure. Both packages may need a fix: https://github.com/opis/closure/issues

[nunomaduro]

Fixed. If you are using the latest version of the framework, please run composer update laravel/serializable-closure.

[driesvints]

We released v1.0.1 of serializable closure which should fix this.