use strict;
use warnings;

my $headline = <DATA>;
my %HoA;
while ( <DATA> ) {
   s/null/0/g;
   # no warnings 'numeric';
   next unless /^\w/;
   chomp;
   my ( $name, @res ) = split /\s*\|\s*/;
   $HoA{$name} = ! $HoA{$name}
      ? [ @res ] 
      : [ map { $HoA{$name}[$_] + $res[$_] } 0 .. $#res ];
}

print $headline;
{
   local $" = ' | ';
   print "$_: @{ $HoA{$_} }\n" for ( keys %HoA );
}

__DATA__
name | passed | failed | pending
-----+--------+--------+---------
xxx | null | 2 | null
xxx | 30 | null | null
xxx | null | null | 10
yyy| 6 | null | null