Global middleware in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What happens when a global middleware returns a response early?

In Laravel, if a global middleware returns a response before calling $next($request), what is the effect on the request lifecycle?

Laravel

public function handle($request, Closure $next)
{
    if ($request->header('X-Block')) {
        return response('Blocked by middleware', 403);
    }
    return $next($request);
}

A The request stops and the response is sent immediately, skipping all other middleware and the controller.

B The request continues to the next middleware but the response is ignored.

C The middleware throws an error because it must always call $next($request).

D The middleware modifies the request but the response is delayed until the controller finishes.

💡 Hint

Think about what happens if middleware returns a response without calling the next middleware.

When a global middleware returns a response early, Laravel stops processing further middleware and the controller. The response is sent immediately to the client.

📝 Syntax

intermediate

Identify the syntax error in this global middleware registration

Which option correctly registers a global middleware in Laravel's app/Http/Kernel.php file?

Laravel

protected $middleware = [
    \App\Http\Middleware\CheckAge::class,
];

A

protected $middleware = [
    App\Http\Middleware\CheckAge::class,
];

B

protected $middleware = [
    \App\Http\Middleware\CheckAge::class,
];

C

protected $middleware = [
    'App\Http\Middleware\CheckAge',
];

D

protected $middleware = [
    \App\Http\Middleware\CheckAge::class
];

💡 Hint

Remember the correct way to reference a class with namespace in PHP arrays.

In PHP, class names with namespaces must be prefixed with a backslash and end with ::class to get the fully qualified class name. The array must have commas after each element.

❓ state_output

advanced

What is the output after applying this global middleware?

Given this global middleware that adds a header, what will the client receive?

Laravel

public function handle($request, Closure $next)
{
    $response = $next($request);
    $response->headers->set('X-Global', 'Active');
    return $response;
}

A The response does not include the <code>X-Global</code> header because headers cannot be modified after $next.

B The middleware causes a runtime error because headers are immutable.

C The response includes the header <code>X-Global: Active</code>.

D The response includes the header <code>X-Global</code> but with an empty value.

💡 Hint

Think about how middleware can modify the response after calling $next.

Middleware can modify the response object after calling $next($request). Here it adds a custom header before returning the response.

🔧 Debug

advanced

Why does this global middleware not run for some routes?

Consider this global middleware registered in Kernel.php. It does not run for routes using the 'api' middleware group. Why?

Laravel

protected $middleware = [
    \App\Http\Middleware\CheckUser::class,
];

protected $middlewareGroups = [
    'web' => [
        // web middleware
    ],
    'api' => [
        'throttle:api',
        'auth:api',
    ],
];

A The 'api' middleware group does not include global middleware, but global middleware runs for all routes regardless.

B Global middleware always runs for all routes; the issue is elsewhere.

C The middleware is registered globally but the 'api' routes use a different HTTP kernel instance.

D The 'api' middleware group overrides global middleware, so global middleware is skipped.

💡 Hint

Recall how Laravel applies global middleware versus middleware groups.

Global middleware runs for every HTTP request regardless of middleware groups. If the middleware does not run, the problem is likely in the middleware logic or route definition, not in registration.

🧠 Conceptual

expert

How does Laravel prioritize global middleware compared to route middleware?

In Laravel, when a request is handled, in what order are global middleware and route middleware executed?

A Global middleware run only if route middleware allow the request to proceed.

B Route middleware run first, then global middleware, then controller.

C Global and route middleware run simultaneously in parallel before the controller.

D Global middleware run first, then route middleware, then controller.

💡 Hint

Think about the middleware layers and their scope in Laravel.

Laravel runs global middleware first on every request. Then it runs any route middleware assigned to the route. Finally, the controller handles the request.