Obtain a response from a Controller object without needing routes, for the purposes of testing

AnonymousResponse.php

<?php

namespace Tests;

use Orchestra\Testbench\TestCase;
use Illuminate\Http\{Request, Response};
use Illuminate\Routing\{Controller, ControllerDispatcher, Pipeline, Route, Router};

/**
 * Trait AnonymousResponse
 * @package Tests
 * @mixin TestCase
 */
trait AnonymousResponse
{
    /**
     * @param Controller $controller
     * @param string $methodName
     * @param Request|null $request
     * @return Response
     */
    protected function generateResponse(Controller $controller, string $methodName, Request $request = null)
    {
        $request = $request ?: Request::create(config('app.url'));
        $route = $this->applyRoute($request, $controller, $methodName);
        $this->applyMiddleware($request, $controller, $methodName);

        return $route->run();
    }

    /**
     * @param Request $request
     * @param Controller $controller
     * @param string $methodName
     * @return Route
     */
    protected function applyRoute(Request $request, Controller $controller, string $methodName)
    {
        $action = ['as' => $methodName, 'uses' => "@$methodName"];
        $route = app(Router::class)->addRoute(['GET'], $methodName, $action)->bind($request);
        $route->controller = $controller;
        $this->app->instance('request', $request->setRouteResolver(function () use ($route) {
            return $route;
        }));

        return $route;
    }

    /**
     * @param Request $request
     * @param Controller $controller
     * @param string $methodName
     * @return Response
     */
    protected function applyMiddleware(Request $request, Controller $controller, string $methodName)
    {
        $middleware = app(ControllerDispatcher::class)->getMiddleware($controller, $methodName);
        $pipeline = app(Pipeline::class, ['container' => $this->app])->send($request)->through($middleware);

        return $pipeline->then(function (Request $request) {
            return $request;
        });
    }
}