Simulate a http request and parse route parameters in Laravel testcase

I assume you need to simulate a request without actually dispatching it. With a simulated request in place, you want to probe it for parameter values and develop your testcase.

There's an undocumented way to do this. You'll be surprised!

The problem

As you already know, Laravel's Illuminate\Http\Request class builds upon Symfony\Component\HttpFoundation\Request. The upstream class does not allow you to setup a request URI manually in a setRequestUri() way. It figures it out based on the actual request headers. No other way around.

OK, enough with the chatter. Let's try to simulate a request:

<?php

use Illuminate\Http\Request;

class ExampleTest extends TestCase
{
    public function testBasicExample()
    {
        $request = new Request([], [], ['info' => 5]);

        dd($request->route()->parameter('info'));
    }
}

As you mentioned yourself, you'll get a:

Error: Call to a member function parameter() on null

We need a Route

Why is that? Why route() returns null?

Have a look at its implementation as well as the implementation of its companion method; getRouteResolver(). The getRouteResolver() method returns an empty closure, then route() calls it and so the $route variable will be null. Then it gets returned and thus... the error.

In a real HTTP request context, Laravel sets up its route resolver, so you won't get such errors. Now that you're simulating the request, you need to set up that by yourself. Let's see how.

<?php

use Illuminate\Http\Request;
use Illuminate\Routing\Route;

class ExampleTest extends TestCase
{
    public function testBasicExample()
    {
        $request = new Request([], [], ['info' => 5]);

        $request->setRouteResolver(function () use ($request) {
            return (new Route('GET', 'testing/{info}', []))->bind($request);
        });

        dd($request->route()->parameter('info'));
    }
}

See another example of creating Routes from Laravel's own RouteCollection class.

Empty parameters bag

So, now you won't get that error because you actually have a route with the request object bound to it. But it won't work yet. If we run phpunit at this point, we'll get a null in the face! If you do a dd($request->route()) you'll see that even though it has the info parameter name set up, its parameters array is empty:

Illuminate\Routing\Route {#250
  #uri: "testing/{info}"
  #methods: array:2 [
    0 => "GET"
    1 => "HEAD"
  ]
  #action: array:1 [
    "uses" => null
  ]
  #controller: null
  #defaults: []
  #wheres: []
  #parameters: [] <===================== HERE
  #parameterNames: array:1 [
    0 => "info"
  ]
  #compiled: Symfony\Component\Routing\CompiledRoute {#252
    -variables: array:1 [
      0 => "info"
    ]
    -tokens: array:2 [
      0 => array:4 [
        0 => "variable"
        1 => "/"
        2 => "[^/]++"
        3 => "info"
      ]
      1 => array:2 [
        0 => "text"
        1 => "/testing"
      ]
    ]
    -staticPrefix: "/testing"
    -regex: "#^/testing/(?P<info>[^/]++)$#s"
    -pathVariables: array:1 [
      0 => "info"
    ]
    -hostVariables: []
    -hostRegex: null
    -hostTokens: []
  }
  #router: null
  #container: null
}

So passing that ['info' => 5] to Request constructor has no effect whatsoever. Let's have a look at the Route class and see how its $parameters property is getting populated.

When we bind the request object to the route, the $parameters property gets populated by a subsequent call to the bindParameters() method which in turn calls bindPathParameters() to figure out path-specific parameters (we don't have a host parameter in this case).

That method matches request's decoded path against a regex of Symfony's Symfony\Component\Routing\CompiledRoute (You can see that regex in the above dump as well) and returns the matches which are path parameters. It will be empty if the path doesn't match the pattern (which is our case).

/**
 * Get the parameter matches for the path portion of the URI.
 *
 * @param  \Illuminate\Http\Request  $request
 * @return array
 */
protected function bindPathParameters(Request $request)
{
    preg_match($this->compiled->getRegex(), '/'.$request->decodedPath(), $matches);
    return $matches;
}

The problem is that when there's no actual request, that $request->decodedPath() returns / which does not match the pattern. So the parameters bag will be empty, no matter what.

Spoofing the request URI

If you follow that decodedPath() method on the Request class, you'll go deep through a couple of methods which will finally return a value from prepareRequestUri() of Symfony\Component\HttpFoundation\Request. There, exactly in that method, you'll find the answer to your question.

It's figuring out the request URI by probing a bunch of HTTP headers. It first checks for X_ORIGINAL_URL, then X_REWRITE_URL, then a few others and finally for the REQUEST_URI header. You can set either of these headers to actually spoof the request URI and achieve minimum simulation of a http request. Let's see.

<?php

use Illuminate\Http\Request;
use Illuminate\Routing\Route;

class ExampleTest extends TestCase
{
    public function testBasicExample()
    {
        $request = new Request([], [], [], [], [], ['REQUEST_URI' => 'testing/5']);

        $request->setRouteResolver(function () use ($request) {
            return (new Route('GET', 'testing/{info}', []))->bind($request);
        });

        dd($request->route()->parameter('info'));
    }
}

To your surprise, it prints out 5; the value of info parameter.

Cleanup

You might want to extract the functionality to a helper simulateRequest() method, or a SimulatesRequests trait which can be used across your test cases.

Mocking

Even if it was absolutely impossible to spoof the request URI like the approach above, you could partially mock the request class and set your expected request URI. Something along the lines of:

<?php

use Illuminate\Http\Request;
use Illuminate\Routing\Route;

class ExampleTest extends TestCase
{

    public function testBasicExample()
    {
        $requestMock = Mockery::mock(Request::class)
            ->makePartial()
            ->shouldReceive('path')
            ->once()
            ->andReturn('testing/5');

        app()->instance('request', $requestMock->getMock());

        $request = request();

        $request->setRouteResolver(function () use ($request) {
            return (new Route('GET', 'testing/{info}', []))->bind($request);
        });

        dd($request->route()->parameter('info'));
    }
}

This prints out 5 as well.