1, 'b', 'c' => 'world'])->toHaveKey('c'); }); test('failures', function () { expect(['a' => 1, 'b', 'c' => 'world'])->toHaveKey('hello'); })->throws(ExpectationFailedException::class); test('not failures', function () { expect(['a' => 1, 'hello' => 'world', 'c'])->not->toHaveKey('hello'); })->throws(ExpectationFailedException::class);