Feature testing with Stache

Using either php please test or php artisan test to run feature tests, I am finding that the Statamic cache is being built from scratch each time, causing very high load times for each test.

As an example, if I load /my_url in the web browser for the first time, it takes 6s to load but if I run it a second time, it takes 530ms because everything is already cached, just as you would expect with Statamic.

However, consider this very simple test:

use Tests\TestCase;

class ThingyTest extends TestCase
{
    /**
     * A basic feature test example.
     *
     * @return void
     */
    public function test_example()
    {
        $response = $this->get('/my_url');

        $response->assertStatus(200);
    }
}

This literally takes 6s every time I run it. So it would quickly become impossible to do effective TDD if I wrote tests for my entire application.

I'm also struggling to find up-to-date reference material about testing in Statamic. The v2 docs has https://v2.statamic.com/testing but the referenced Statamic\Testing\TestCase doesn't appear to exist in v3 and there doesn't seem to be any information in the v3 docs about testing at all. I was hoping that there would just be something like a --with-cache flag I could use but apparently there isn't.