/** * @dataProvider oneToTen */ public function testGroupJoinApplyToSelfWithInnerIndexBy(\Pinq\ICollection $collection) { $inner = $collection->indexBy(function ($i) { return $i - 1; })->select(function ($i) { return (int) $i; }); $collection->groupJoin($inner)->on(function ($outer, $inner) { return $outer > $inner; })->apply(function (&$outer, \Pinq\ITraversable $group) { $outer .= ':' . $group->implode(','); }); $this->assertMatches($collection, [0 => '1:', 1 => '2:1', 2 => '3:1,2', 3 => '4:1,2,3', 4 => '5:1,2,3,4', 5 => '6:1,2,3,4,5', 6 => '7:1,2,3,4,5,6', 7 => '8:1,2,3,4,5,6,7', 8 => '9:1,2,3,4,5,6,7,8', 9 => '10:1,2,3,4,5,6,7,8,9']); }