How To Test Routes' Middleware?

Let's say I have a group of routes which are protected by a middleware:

Route::group(['middleware' => 'verified'], function () {
    Route::get('/profile', '[email protected]')->name('profile.show');
    Route::get('/settings', '[email protected]')->name('settings.show');
});

How can I test that these routes are protected by verified middleware? If I write those tests, are they considered as feature tests or unit tests?

Middleware testing highly depends on the logic of the middleware itself and on the possible outcomes. Let's take the verified middleware you cited as an example:

We expect the user to be redirected (302) to the "Verify your email" page if it has not verified his email (the email_verified_at attribute is null), otherwise we expect a normal response (200).

How can we simulate a user accessing our page? With the actingAs method. From the docs:

The actingAs helper method provides a simple way to authenticate a given user as the current user.

So our code will look something like this:

use App\User;

class ExampleTest extends TestCase
{
    public function testAccessWithoutVerification()
    {
        // Create a dummy user
        $user = factory(User::class)->create();

        // Try to access the page
        $response = $this->actingAs($user)
                         ->get('/the-page-we-want-to-test');

        // Assert the expected response status
        $response->assertStatus(302);
    }

    public function testAccessWithVerification()
    {
        // Create a dummy user, but this time we set the email_verified_at
        $user = factory(User::class)->create([
            'email_verified_at' => \Carbon\Carbon::now(),
        ]);

        // Try to access the page
        $response = $this->actingAs($user)
                         ->get('/the-page-we-want-to-test');

        // Assert the expected response status
        $response->assertStatus(200);
    }

}

The docs have an entire page dedicated to HTTP tests, check it out.