toBeEmpty(); expect(null)->toBeEmpty(); }); test('failures', function () { expect([1, 2])->toBeEmpty(); expect(' ')->toBeEmpty(); })->throws(ExpectationFailedException::class); test('failures with custom message', function () { expect([1, 2])->toBeEmpty('oh no!'); expect(' ')->toBeEmpty('oh no!'); })->throws(ExpectationFailedException::class, 'oh no!'); test('not failures', function () { expect([])->not->toBeEmpty(); expect(null)->not->toBeEmpty(); })->throws(ExpectationFailedException::class);