/** * @dataProvider subjectProvider * @covers ::foldRight */ public function test_foldRight_direction(testSubject $subject) { $expected = $subject->reverse()->keys()->toArray(); $assembleKeys = function ($p, $v, $k, $c) { $p[] = $k; return $p; }; $result = $subject->foldRight($assembleKeys, []); self::assertEquals($expected, $result); }