I use Test::Deep quite a bit and like it but the following structure has defeated me as to coming up with a matching structure:

 [
   11,
   22, # optional
   [
     [
      1
     ],
     [  #
      -1 # only here if 2 above is there
     ]  #
   ]
]
[download]

so I get:

[11,22,[[1],[-1]]]

or

[11,[[1]]

The closest I've got is:

use Test::More tests => 2;
use Test::Deep;

my $id_re = re('^\d+$');
my $vpt_re = re('^-?1$');

my $x = [
          '11',
          '22',
          [
            [
              '-1',
            ],
            [                   # 
              '1',              # only present if '22' above present
            ]                   # 
          ]
        ];

my $y = [
          '11',
          [
            [
              '-1',
            ],
          ]
        ];

my $comp =
    [
        $id_re,
        $id_re,
        subbagof([$vpt_re], [$vpt_re])
    ];

cmp_deeply($x, $comp, 'test1');
cmp_deeply($y, $comp, 'test2');
[download]

but it does not handle a) the optional $id_re at the top level and the subbagof allows none. I tried to put it all in a subbagof but the problem with subbags is it depends on what matches first.

Obviously I could test to see if it is an arrayref then use one of 2 patterns depending on whether the array contains 2 or 3 items but that seems like a cop out.