How to catch PHP Warning in PHPUnit

Question

I am writing test cases and here is a question I have.

So say I am testing a simple function someClass::loadValue($value)

The normal test case

Answer 1

I would create a separate case to test when the notice/warning is expected.

For PHPUnit v6.0+ this is the up to date syntax:

use PHPUnit\Framework\Error\Notice;
use PHPUnit\Framework\Error\Warning;
use PHPUnit\Framework\TestCase;

class YourShinyNoticeTest extends TestCase
{

    public function test_it_emits_a_warning()
    {
        $this->expectException(Warning::class);

        file_get_contents('/nonexistent_file'); // This will emit a PHP Warning, so test passes
    }


    public function test_it_emits_a_notice()
    {
        $this->expectException(Notice::class);

        $now = new \DateTime();
        $now->whatever; // Notice gets emitted here, so the test will pass
    }
}