Show your code anyway?
use warnings;
use strict;
use Test::More;
my @AoH = (
{'targetL' => 'foisonnement', 'origin' => 'AMG', 'count' => '1'},
{'targetL' => 'foisonnement', 'origin' => 'IDBR', 'count' => '1'},
{'targetL' => 'gonfler', 'origin' => 'IWWF', 'count' => '1'},
{'targetL' => 'due', 'origin' => 'IWWF', 'count' => '1' },
{'targetL' => 'due', 'origin' => 'IWWF', 'count' => '1' },
);
my @AoHfinal;
my %targets;
for my $h (@AoH) {
push @AoHfinal, ($targets{$$h{targetL}}={targetL=>$$h{targetL}})
unless $targets{$$h{targetL}};
$targets{$$h{targetL}}{origin}{$$h{origin}}++;
$targets{$$h{targetL}}{count}++;
}
$$_{origin} = join ' ', sort keys %{$$_{origin}} for values %targets;
is_deeply \@AoHfinal, [
{'targetL' => 'foisonnement','origin' => 'AMG IDBR','count'=>'2'},
{'targetL' => 'gonfler','origin' => 'IWWF','count' => '1'},
{'targetL' => 'due','origin' => 'IWWF','count' => '2'},
] or diag explain \@AoHfinal;
done_testing;
Note you didn't specify the order of the resulting values, both @AoHfinal (so I kept the original order from @AoH), or of the origin values (so I sorted them because it was easier).
