Perl: What is the definition of a test?

Question

I feel a bit ashamed to ask this question but I am curious. I recently wrote a script (without organizing the code in modules) that reads log files of a store and saves the info to the data base.

For example, I wrote something like this (via Richard Huxton):

while (<$infile>) {
    if (/item_id:(\d+)\s*,\s*sold/) {
        my $item_id = $1;
        $item_id_sold_times{$item_id}++;
    }
}
my @matched_items_ids = keys %item_id_sold_times;
my $owner_ids =
  Store::Model::Map::ItemOwnerMap->fetch_by_keys( \@matched_item_ids )
  ->entry();
for my $owner_id (@$owner_ids) {
    $item_id_owner_map{$owner_id}++;
}

Say, this script is called script.pl. When testing the file, I made a file script.t and had to repeat some blocks of script.pl in script.t. After copy pasting relevant code sections, I do confirmations like:

is( $item_id_sold_times{1}, 1, "Number of sold items of item 1" );
is( $item_id_owner_map{3},  8, "Number of sold items for owner 3" );

And so on and so on.

But some have pointed out that what I wrote is not a test. It is a confirmation script. A good test would involve writing the code with modules, writing a script that kicks the methods in the modules and write a test for the module.

This has made me think about what is the definition of a test most widely used in software engineering. Perhaps some of you that have even tested Perl core functions can give me a hand. A script (not modulized) cannot be properly tested?

Regards

Answer 1

An important distinction is: If someone were to edit (bugfix or new feature) your 'script.pl' file, would running your 'script.t' file in its current state give any useful information on the state of the new 'script.pl'? For this to be the case you must include or use the .pl file instead of selectively copy/pasting excerpts.

In the best case you design your software modularly and plan for testing. If you want to test a monolithic script after the fact, I suppose you could write a test script that includes your main program after an exit() and at least have the subroutines to test...