The Daily WTF: Curious Perversions in Information Technology

Tern Down a Date

by Remy Porter in Representative Line on 2025-03-25

Today's anonymous submitter has managed to find a way to do date formatting wrong that I don't think I've seen yet. That's always remarkable. Like most such bad code, it checks string lengths and then adds a leading zero, if needed. It's not surprising, but again, it's all in the details:

// convert date string to yyyy/MM/DD
return dtmValue.Year + "-" + ((dtmValue.Month.ToString().Length == 1)?  ("0" + dtmValue.Month.ToString()): dtmValue.Month.ToString()) + "-" + ((dtmValue.Day.ToString().Length == 1)? ("0" + dtmValue.Day.ToString()): dtmValue.Day.ToString());

13 comments - Last comment @ 11:39

The Rounding Error

by Remy Porter in Representative Line on 2025-03-24

At one point, someone noticed that some financial transactions weren't summing up correctly in the C# application Nancy supported. It didn't require Superman or a Peter Gibbons to figure out why: someone was using floating points for handling dollar amounts.

That kicked off a big refactoring project to replace the usage of double types with decimal types. Everything seemed to go well, at least until there was a network hiccup and the application couldn't connect to the database. Let's see if you can figure out what happened:

18 comments - Last comment @ 09:50

Over Extended Methods

by Remy Porter in Feature Articles on 2025-03-20

Jenny had been perfectly happy working on a series of projects for her company, before someone said, "Hey, we need you to build a desktop GUI for an existing API."

The request wasn't the problem, per se. The API, on the other hand, absolutely was.

17 comments - Last comment @ 2025-03-20

Reliability Test

by Remy Porter in CodeSOD on 2025-03-19

Once upon a time, Ryan's company didn't use a modern logging framework to alert admins when services failed. No, they used everyone's favorite communications format, circa 2005: email. Can't reach the database? Send an email. Unhandled exception? Send an email. Handled exception? Better send an email, just in case. Sometimes they go to admins, sometimes they just go to an inbox used for logging.

Let's look at how that worked.

19 comments - Last comment @ 2025-03-23

Spaced Out Prefix

by Remy Porter in CodeSOD on 2025-03-18

Alex had the misfortune to work on the kind of application which has forms with gigantic piles of fields, stuffed haphazardly into objects. A single form could easily have fifty or sixty fields for the user to interact with.

That leads to C# code like this:

16 comments - Last comment @ 10:07

Don't Date Me

by Remy Porter in CodeSOD on 2025-03-13

I remember in some intro-level compsci class learning that credit card numbers were checksummed, and writing basic functions to validate those checksums as an exercize. I was young and was still using my "starter" credit card with a whopping limit of $500, so that was all news to me.

Alex's company had a problem processing credit cards: they rejected a lot of credit cards as being invalid. The checksum code seemed to be working fine, so what could the problem be? Well, the problem became more obvious when someone's card worked one day, and stopped working the very next day, and they just so happened to be the first and last day of the month.

14 comments - Last comment @ 2025-03-19

Expressing a Leak

by Remy Porter in CodeSOD on 2025-03-12

We previously discussed some whitespacing choices in a C++ codebase. Tim promised that there were more WTFs lurking in there, and has delivered one.

Let's start with this class constructor:

20 comments - Last comment @ 2025-03-13

Broken Up With

by Remy Porter in Representative Line on 2025-03-11

Marco found this wreck, left behind by a former co-worker:

$("#image_sample").html('<i><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br />No image selected, select an image to see how it looks in the banner!</i>');

28 comments - Last comment @ 2025-03-24

Where is the Validation At?

by Remy Porter in CodeSOD on 2025-03-10

As oft stated, the "right" way to validate emails is to do a bare minimum sanity check on format, and then send a verification message to the email address the user supplied; it's the only way to ensure that what they gave you isn't just syntactically valid, but is actually usable.

But even that simple approach leaves places to go wrong. Take a look at this code, from Lana.

15 comments - Last comment @ 2025-03-11

An Argument With QA

by Remy Porter in CodeSOD on 2025-03-06

Markus does QA, and this means writing automated tests which wrap around the code written by developers. Mostly this is a "black box" situation, where Markus doesn't look at the code, and instead goes by the interface and the requirements. Sometimes, though, he does look at the code, and wishes he hadn't.

Today's snippet comes from a program which is meant to generate PDF files and then, optionally, email them. There are a few methods we're going to look at, because they invested a surprising amount of code into doing this the wrong way.

9 comments - Last comment @ 2025-03-07

Wrap Up Your Date

by Remy Porter in CodeSOD on 2025-03-05

Today, we look at a simple bit of bad code. The badness is not that they're using Oracle, though that's always bad. But it's how they're writing this PL/SQL stored function:

  FUNCTION CONVERT_STRING_TO_DATE --Public
    (p_date_string IN Varchar2,
       p_date_format IN Varchar2 DEFAULT c_date_format)
    Return Date

   AS

   BEGIN

    If p_date_string Is Null Then
        Return Null;
      Else
        Return To_Date(p_date_string, p_date_format);
      End If;

   END;  -- FUNCTION CONVERT_STRING_DATE

20 comments - Last comment @ 2025-03-07

The Sales Target

by Remy Porter in Feature Articles on 2025-03-04

The end of the quarter was approaching, and dark clouds were gathering in the C-suite. While they were trying to be tight lipped about it, the scuttlebutt was flowing freely. Initech had missed major sales targets, and not just by a few percentage points, but by an order of magnitude.

Heads were going to roll.

16 comments - Last comment @ 2025-03-07

An Alerting Validation

by Remy Porter in CodeSOD on 2025-03-03

There are things which are true. Regular expressions frequently perform badly. They're hard to read. Email addresses are not actually regular languages, and thus can't truly be validated (in all their many possible forms) by a pure regex.

These are true. It's also true that a simple regex can get you most of the way there.

26 comments - Last comment @ 2025-03-11