use Perl

• Test what you use. (Score:1)

  by Eric Wilhelm (6389)

  Adding in all of the other "silly" tests would likely be a waste of time, but not if you're writing software to control a nuclear reactor.

  I like Schwern's "test bugs" philosophy for any sort of maintenance testing.

  For new code, I probably wouldn't even write a unit test for reciprocal() -- but I wouldn't have a function for reciprocal() except in a general-purpose math library. And in such a library, yes I would probably have more "silly" tests, but also better diagnostics built into the function.

  But for s
• dodging the question (Score:1)

  by dug (2501)

  I'm probably not doing a good job of answering "what do you test", but that's okay, my test suite gives me a pass [grin].

  I'd be worried enough that someone would accidentally throw some code together that uses reciprocal as an object method (and therefore uses an int-ified string-ified object as the divisor) that I would probably add some parameter validation, and then just test that my validation worked. I wouldn't feel the need to test the / operator.

  -- Douglas Hunter
• A Good Type System (Score:1)

  by chromatic (983)

  This is one of the cases where a good strict typing system really helps (though I'd want the system to enforce all overloading of the division operator such that mathematic invariants hold).
• Don't forget to test ... (Score:2)

  by drhyde (1683)

  ... that it gives a true but incorrect value for the reciprocal of three. Or indeed for anything that has any non-2 factor :-)
  • Re: (Score:2)

    by Ovid (2709)

    You're just making life difficult :)
• easy, be more strict. (Score:1)

  by notbenh (7967)

  You can simply enforce typing:

  use Carp::Assert::More;

  sub recip {
        my ($num) = @_;
        assert_nonzero($num);
        return 1/$num;
  }

  Then write one test to make sure that it works:

  is( recip(2), .5 );

  one to show that it dies correctly:

  dies_ok sub{recip(0)};

  and your done, any bugs that come up later can be tested then.

  --
  benh~