You know how some people put those little badges in their readme files in GitHub?

Well, one of my team members didn't know how to make those work correctly, so they just plastered images of them to make our repo look good. In actuality we have no coverage, no testing, no nothing...

Most painful code error you've made?

More than I probably care to count.

One in particular where I was asked to integrate our code and converted the wrong value..ex

The correct code was supposed to be ...

var serviceBusMessage = new Message() {ID = dto.InvoiceId ...}

but I wrote ..

var serviceBusMessage = new Message() {ID = dto.OrderId ...}

At the time of the message bus event, the dto.OrderId is zero (it's set after a successful credit card transaction in another process)

Because of a 'true up' job that occurs at EOD, the issue went unnoticed for weeks. One day the credit card system went down and thousands of invoices needed to be re-processed, but seemed to be 'stuck', and 'John' was tasked to investigate, found the issue, and traced back to the code changes.

John: "There is a bug in the event bus, looks like you used the wrong key and all the keys are zero."
Me: "Oh crap, I made that change weeks ago. No one noticed?"
John: "Nah, its not a big deal. The true-up job cleans up anything we missed and in the rare event the credit card system goes down, like now. No worries, I can fix the data and the code."
<about an hour later I'm called into a meeting>
Mgr1: "We're following up on the credit card outage earlier. You made the code changes that prevented the cards from reprocessing?"
Me: "Yes, it was my screw up."
Mgr1: "Why wasn't there a code review? It should have caught this mistake."
Mgr2: "All code that is deployed is reviewed. 'Tom' performed the review."
Mgr1: "Tom, why didn't you catch that mistake."
Tom: "I don't know, that code is over 5 years old written by someone else. I assumed it was correct."
Mgr1: "Aren't there unit tests? Integration tests?"
Tom: "Oh yea, and passed them all. In the scenario, the original developers probably never thought the wrong ID would be passed."
Mgr1: "What are you going to do so this never happens again?"
Tom: "Its an easy addition to the tests. Should only take 5 minutes."
Mgr1: "No, what are *you* going to do so this never happens again?"
Me: "It was my mistake, I need to do a better job in paying attention. I knew what value was supposed to passed, but I screwed up."
Mgr2: "No harm no foul. We didn't lose any money and no customer was negativity affected. Credit card system may go down once, or twice a year? Nothing to lose sleep over. Thanks guys."

A week later Mgr1 fires Tom.

I feel/felt like a total d-bag.

Talking to 'John' later about it, turns out Tom's attention to detail and 'passion' was lacking in other areas. Understandable since he has 2 kids + one with special-needs, and in the middle of a divorce, taking most/all of his vacation+sick time (which 'Mgr1' dislikes people taking more than a few days off, that's another story) and 'Mgr1' didn't like Tom's lack of work ethic (felt he needed to leave his problems at home). The outage and the 'lack of due diligence' was the last straw.

The feature was to parse a set of fairly complex xml files following a legacy schema. Problem was, the way this was done previously did not conform to the schema so it was a guideline at best, which over the course of many years snowballed into an anarchy where clients would send in whatever and it was continuously updated per case as needed. They wanted to start enforcing their new schema while phasing out the old method.

The good news is that parsing and serialization is very testable, so I rounded up what I could find of example files and got to work. Around the same time I asked our client if they had any more examples of typical cases we need to deal with, and sure enough a couple of days later I receive a zip with hundreds of files. They also point out that I should just disregard the entire old set since they decided to outright cut support for it after all if it makes things simpler. Nice.

I finish the feature in a decent amount of time. All my local tests pass, and the CD tests pass when I push my branches. Once we push to our QA env though and the integration tests run, we get a pass rate of less than 10%.

I spend a couple of days trying to figure out what's going on, and eventually narrow it down to some wires being crossed with the new vs. old xml formats. I'm at a loss. I keep trying to chip away at it until I'm left with a minimal example, and I have one of those lean-back moments where you're just "I don't get it". My tests pass locally, but in the QA environment they fail on the same files.

We're now 3 people around my workstation including the system architect, and I'm demonstrating to the others how baffling and black magic this is. I postulate that maybe something is cached in my local environment and it's not actually testing the new files. I even deleted the old ones.

"Are you sure you deleted the right files?"

"Duh of course -- but let me check..."