Laravel 5 middleware class that sets a context in a multi-tenant app + updated version for easier testing with example testcase.

1.Summary.md

I wrote a middleware class that sets a singleton "Context" based upon either a domain or subdomain. This was an untested class and was refactored for testing with some help from @adamwathan (https://gist.github.com/adamwathan/d8dd4ea5337eb3f975b8).

2.TenantMiddleware.php

<?php namespace Kilo\Http\Middleware;

use Closure;
use Route;
use App;

use Kilo\Models\TenantSpecific\Tenant;

class TenantMiddleware {

	protected $domain;
	protected $tld;
	protected $subdomain;
	protected $tenant;
	protected $full_domain;

	/**
	 * Handle an incoming request.
	 *
	 * @param  \Illuminate\Http\Request  $request
	 * @param  \Closure  $next
	 * @return mixed
	 */
	public function handle($request, Closure $next)
	{
		
		$domain = Route::input('domain');
		$tld = Route::input('tld');
		$subdomain = Route::input('subdomain');

		$full_domain = $domain . '.' . $tld;

		/**
		 * Get the Tenant by either domain or subdomain.
		 * If no Tenant found redirect to app home.
		 */
		if(isset($domain) && $full_domain != env('APP_DOMAIN')) {

			$tenant = Tenant::getByDomain($full_domain);

		} elseif (isset($subdomain)) {

			$tenant = Tenant::getBySubdomain($subdomain);
		} else {

			$tenant = NULL;
		}

		return $this->setContext($tenant) ? $next($request) : redirect()->route('app-home');
	}

	/**
	 * Sets the context
	 * @param Kilo\Models\TenantSpecific\Tenant $tenant
	 */
	public function setContext($tenant) {

		if(!isset($tenant)) {

			return false;
		}

		$context = App::make('Context');
		$context->set($tenant);

		return true;
	}
}

3.TenantMiddleware.php

<?php namespace Kilo\Http\Middleware;

/**
 * Updated version for easier testability.
 * Cheers @adamwathan for helping me wrap my head around this.
 */

use Closure;

use Illuminate\Routing\Redirector as Redirect;

use Kilo\Models\TenantSpecific\Tenant;
use Kilo\Models\TenantSpecific\TenantContext as Context;

class TenantMiddleware {

	protected $tenant;
	protected $context;
	protected $redirect;

	public function __construct(Tenant $tenant, Context $context, Redirect $redirect)
	{
		$this->tenant = $tenant;
		$this->context = $context;
		$this->redirect = $redirect;
	}

	/**
	 * Handle an incoming request.
	 *
	 * @param  \Illuminate\Http\Request  $request
	 * @param  \Closure  $next
	 * @return mixed
	 */
	public function handle($request, Closure $next)
	{
		$domain = $request->route('domain');
		$tld = $request->route('tld');
		$subdomain = $request->route('subdomain');

		$full_domain = $domain . '.' . $tld;

		$current_tenant = NULL;

		// Get the tenant by domain.
		if(isset($domain) && $full_domain != env('APP_DOMAIN')) {

			$current_tenant = $this->tenant->getByDomain($full_domain);

		// Get the tenant by subdomain.
		} elseif (isset($subdomain)) {

			$current_tenant = $this->tenant->getBySubdomain($subdomain);
		}

		// Set the context if a tenant is found, else redirect to app home.
		return $this->setContext($current_tenant) ? $next($request) : $this->redirect->route('app-home');
	}

	/**
	 * Set the context.
	 * @param Kilo\Models\TenantSpecific\Tenant $current_tenant
	 * @return  Boolean
	 */
	public function setContext($current_tenant) {

		if(!isset($current_tenant)) {

			return false;
		}

		$this->context->set($current_tenant);

		return true;
	}
}

4.TenantMiddlewareSpec.php

<?php

/**
 * Example testcases written for PhpSpec framework.
 */

namespace spec\Kilo\Http\Middleware;

use PhpSpec\ObjectBehavior;
use Prophecy\Argument;

use Kilo\Models\TenantSpecific\Tenant;
use Kilo\Models\TenantSpecific\TenantContext as Context;

use Illuminate\Http\Request;
use Illuminate\Routing\Redirector as Redirect;

class TenantMiddlewareSpec extends ObjectBehavior
{
    function let(Tenant $tenant, Context $context, Redirect $redirect)
    {
        $this->beConstructedWith($tenant, $context, $redirect);
    }

    function it_is_initializable()
    {
        $this->shouldHaveType('Kilo\Http\Middleware\TenantMiddleware');
    }

    function it_sets_the_context_by_subdomain(

        Request $request,
        Tenant $tenant,
        Context $context,
        Redirect $redirect,
        Tenant $matchingTenant
    ){
        $next = function () { return 'next'; };

        $request->route('domain')->willReturn(NULL);
        $request->route('tld')->willReturn(NULL);
        $request->route('subdomain')->willReturn('sub');

        $tenant->getBySubdomain('sub')->willReturn($matchingTenant);

        // Ready, set, deal with it!
        $this->handle($request, $next)->shouldReturn($next($request));

        $context->set($matchingTenant)->shouldHaveBeenCalled();
    }

    function it_sets_the_context_by_domain(

        Request $request,
        Tenant $tenant,
        Context $context,
        Redirect $redirect,
        Tenant $matchingTenant
    ){
        $next = function () { return 'next'; };

        $request->route('domain')->willReturn('domain');
        $request->route('tld')->willReturn('tld');
        $request->route('subdomain')->willReturn(NULL);

        $tenant->getByDomain('domain.tld')->willReturn($matchingTenant);

        // Ready, set, deal with it!
        $this->handle($request, $next)->shouldReturn($next($request));

        $context->set($matchingTenant)->shouldHaveBeenCalled();
    }
}