my @Tests = (
    {
       'desc' => 'failure',
       'params' => {},
       'result' => "some error msg",
    },
    {
       'desc' => 'success',
       'params' => {bar=>1, baz=2},
       'result' => "ok",
    },
);

foreach my $test (@Tests) {
    ok(
      sub {
         Foo->new($test->{params});
         'ok';
      };
      'ok',
      "test new() " . ( exists( $test->{'desc'} ) ? " - $test->{'desc'}" : '' )
    );
}