Mock classes & routes in Laravel Dusk tests

DuskServiceProvider.php

<?php

namespace App\Providers;

class DuskServiceProvider extends ServiceProvider
{
    /**
     * The classes that should be mocked for Dusk tests
     *
     * @var array
     */
    protected $classes = [
        AddressVerification::class => AddressVerificationMock::class,
    ];

    /**
     * The additional routes that should be mocked for Dusk tests
     *
     * @var array
     */
    protected $routes = [
        'api/invoices/{invoice}' => [
            'method' => 'GET',
            'action' => InvoiceControllerMock::class
        ],
    ];

    /**
     * Register services.
     *
     * @return void
     */
    public function register()
    {
        if (app()->environment('dusk')) {
            $this->mockClasses();
            $this->mockRoutes();
        }
    }

    /**
     * Mock classes
     *
     * @return void
     */
    protected function mockClasses()
    {
        foreach ($this->classes as $class => $mock) {
            $this->app->instance($class, new $mock);
        }
    }

    /**
     * Mock routes
     *
     * @return void
     */
    protected function mockRoutes()
    {
        $router = app()->make('router');

        foreach ($this->routes as $route => $mock) {
            $router->addRoute($mock['method'], $route, $mock['action']);
        }
    }
}

Dusk is wonderful for testing, but lacks the ability to mock and swap classes like feature and unit tests.

The above service provider makes it possible to mock classes and routes when the environment is set to dusk (typically using .env.dusk.local). In this example, I'm mocking an external API service /api/invoices (utilized by Vue.js components) by overriding my environment variable for the API's endpoint:

Note: the routes functionality will only append new routes, and cannot overwrite existing ones (I might explore that some more down the road, extending RouteCollection's add method)

.env

APP_ENV=production
EXTERNAL_ENDPOINT="https://api.stripe-ish.com"

.env.dusk.local

APP_ENV=dusk
EXTERNAL_ENDPOINT=""