How to use the method setup from PHPUnit in Laravel 5.8

Question

I used to use the method setup of PHPUnit to create a instance for my test methods. But in Laravel 5.8 I can't do it

I've tried both ways, and it's works makes an instance per method how showed below.

This works:

<?php

namespace Tests\Unit;

use Tests\TestCase;
use Illuminate\Foundation\Testing\WithFaker;
use Illuminate\Foundation\Testing\RefreshDatabase;
use App\Service\MyService;

class MyServiceTest extends TestCase
{
    /**
     * A basic unit test example.
     *
     * @return void
     */
    public function testInstanceOf()
    {
        $myService = new MyService;
        $this->assertInstanceOf( 'App\Service\MyService' , $myService );
    }
}

This doesn't works:

<?php

namespace Tests\Unit;

use Tests\TestCase;
use Illuminate\Foundation\Testing\WithFaker;
use Illuminate\Foundation\Testing\RefreshDatabase;
use App\Service\MyService;

class MyServiceTest extends TestCase
{

    private $instance;

    function setUp(){    
      $this->instance = new MyService;
    }
    /**
     * A basic unit test example.
     *
     * @return void
     */
    public function testInstanceOf()
    {
        $myService = $this->instance;
        $this->assertInstanceOf( 'App\Service\MyService' , $myService );
    }
}

This error message below show in console:

PHP Fatal error:  Declaration of Tests\Unit\MyServiceTest::setUp() must be compatible with Illuminate\Foundation\Testing\TestCase::setUp(): void in /home/myproject/tests/Unit/MyServiceTest.php on line 10

Answer 1

Laravel 5.8 added the void typehint to the return type of the setUp method.
So you have to declare that like this:

public function setUp(): void
{
    // you should also call parent::setUp() to properly boot
    // the Laravel application in your tests
    $this->instance = new MyService;
}

Note the : void after the function arguments to state the return type of that function