use Assertions 'test'; plan tests; ASSERT(1 == 1, "an example test"); my %observed = parse_data("a1b4c6"); ASSERT(EQUAL(\%observed, {a => 1, b => 4, c => 6}), 'parse_data, parsed ok'); my $returned = munge_data(\%observed); ASSERT(EQUALS_FILE($returned, 'expected.txt'), 'munge_data is good at munging'); ASSERT(DIED(sub { $object_to_test->method(@bad_inputs) }));