adrema/tests/Feature/Invoice/InvoiceDestroyActionTest.php

<?php

namespace Tests\Feature\Invoice;

use App\Invoice\Models\Invoice;
use App\Invoice\Models\InvoicePosition;
use Illuminate\Foundation\Testing\DatabaseTransactions;

uses(DatabaseTransactions::class);

it('testItDestroysInvoice', function () {
    $this->login()->loginNami()->withoutExceptionHandling();
    $invoice = Invoice::factory()->has(InvoicePosition::factory()->withMember(), 'positions')->create();

    $this->delete(route('invoice.destroy', ['invoice' => $invoice]))->assertOk();
    $this->assertDatabaseCount('invoices', 0);
    $this->assertDatabaseCount('invoice_positions', 0);
});