Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: What's the largest amount of bad code you have ever seen work?

news.ycombinator.com

Post reply on HN
Print view View original

541–550 of 601 posts

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#541

Post by jsgo »

acroback wrote: post #415
Izkata wrote: post #62

Earlier quoted context omitted.

A sentiment among members of a former team was that automated tests meant you didn't need to write understandable code - let the tests do the thinking for you. This, and stuff like your story, are why I don't trust people who promote test-driven development as the best way to write clean APIs.

TDD need to die. This is a curse. There should be integration tests along with some property based tests and fuzzy tests. Usually catches a lot of things.Invest in monitoring and alerts too. TDD is like relying on debugger to solve your problem. Is debugger a good tool? yes,it is a great tool. But using it as an excuse to avoid understanding what happens under the hood is plain wrong. The problem lies in industry whe…

I'm probably not the best to speak on the topic as I don't use TDD (nor have I), but I think the idea is good if maybe a bit unorthodox: leveraging tests to define examples of inputs/outputs and setting "guards" to make sure the result of your code is as you expected via the tests.

I'm not keen on the "cult" of it, but if expectations of what the output should look like are available from the onset, it would appear to be of some benefit, at least.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#542

Post by lojack »

iopq wrote: post #482
lojack wrote: post #468

Earlier quoted context omitted.

Unit tests are a side effect of TDD, they don't have to be the goal. I'd find value out of TDD even if I deleted all of my tests after. It sounds like your problems are around unit tests, and that is neither something required to TDD nor is it something limited to just TDD. The problem with integration tests is they are slow and grow exponentially. If they aren't growing exponentially then there's probably large chun…

No, like in some programs when I figure out how to do it correctly the unit tests are either complete tautologies or integration tests. Then there are the "write once, never fail ever" tests. Okay, so the test made sense when I wrote the code. I will never touch that part ever again because it works perfectly. Why do I keep running them every time?

If the unit tests are tautologies then they aren't testing the right things, and if they are integration tests then they aren't actually unit tests.

I personally run my unit tests every time to confirm my assumptions that the unit of code under test hasn't changed. I also assume all code I write will inevitably be changed in the future because business requirements change and there's always room for improvement. Actually can't think of a single piece of code I've written (apart from code I've thrown out) that didn't eventually need to be rewritten. The benefit of running unit tests is less than the benefit of running integration tests, but the cost of running them is also significantly less. Current project I'm working on has 10x as many unit tests as integration tests and they run 100x faster.

My workflow is usually run my unit tests for the code I'm working on constantly, and when I think things are working run the entire test suite to verify everything works well together. Thats my workflow whether or not I'm doing TDD.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#543

Post by rumpelbums »

oraguy wrote: post #325
mlthoughts2018 wrote: post #309

Earlier quoted context omitted.

Were you even given substantial time to ask the interviewers questions? In most interviews I’ve done, even later round interviews whether it’s a finance company, start-up, FAANG, and companies of all sorts in between, I was given at most 5 minutes to ask questions after some dumb shit whiteboard algo trivia.

I was given 5 minutes to ask questions after each round of interview. That part was ordinary too. That's what most of the other companies do (FAANG or otherwise).

I am not sure what position you were interviewing for and to what level of interview you made it.

When I was interviewing for an SRE position with Google in Dublin, I had about 10min to ask questions in each of the 5 interviews that were conducted on-site.

In between the interviews, a sixth SRE would take me to lunch for about an hour. Anything discussed with him wouldn't be evaluated as part of the interview.

So there was plenty of time for questions, I would say.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#544

Post by julianz »

humanrebar wrote: post #339
rollulus wrote: post #239

At my first gig I teamed up with a guy responsible for a gigantic monolith written in Lua. Originally, the project started as a little script running in Nginx. Over the course of several years, it organically grew to epic proportions, by consuming and replacing every piece of software that it interfaced with - including Nginx. There were two ingredients in the recipe for disaster. The first is that Lua comes "batteri…

I've seen personal reality building happen in Lua several times already. It's very seductive to intelligent solo artists who are given a lot of freedom. To be fair, I've also seen it happen in C, C++, and JavaScript.

"personal reality building" is the greatest quote in this whole thread, it's perfect. Will be using.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#545

Post by Blaisorblade0 »

guscost wrote: post #531
oraguy wrote: post #292

Earlier quoted context omitted.

That would have been fun but in reality there was no downtime. Developers like me were expected to work on two to three bugs/features at a time and context switch between them. If I submit my test jobs today to the farm, the results would come one or two days later, so I work on another bug tomorrow, and submit that. Day after tomorrow, I return to the first bug, and so on.

How would you know that merging code from the first bugfix wouldn't break the (just tested) code from the second bugfix?? Would you assume that the first bugfix will be merged first and branch off of that?

Without knowing Oracle's approach, this sort of problem is no different from any other software, even tho it reaches a larger scale.

Branch from master, and rerun tests before the final merge, like you should in any other software? (Many processes fail that criterion, see https://bors.tech/ for something that gets this right).

Ideally you work on a different enough bug that there's limited interaction, and ideally that's figured out before you fix it, but those criteria are indeed harder to satisfy in a bigger software.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#546

Post by thumb »

oraguy wrote: post #18

Oracle Database 12.2. It is close to 25 million lines of C code. What an unimaginable horror! You can't change a single line of code in the product without breaking 1000s of existing tests. Generations of programmers have worked on that code under difficult deadlines and filled the code with all kinds of crap. Very complex pieces of logic, memory management, context switching, etc. are all held together with thousand…

This sounds a lot like Walmart's codebase for their POS registers. Except, the kicker is that there are zero unit tests, zero test frameworks, etc. You just have to run it through the shitty IBM debugger and hope that you don't step on anyone else's work. Up until 2016, they didn't even have a place to store documentation. Each register has ~1000 flags, some of which can be bit switched further into testing hell.

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#547

Post by skrebbel »

oraguy wrote: post #18

Oracle Database 12.2. It is close to 25 million lines of C code. What an unimaginable horror! You can't change a single line of code in the product without breaking 1000s of existing tests. Generations of programmers have worked on that code under difficult deadlines and filled the code with all kinds of crap. Very complex pieces of logic, memory management, context switching, etc. are all held together with thousand…

Sounds like ASML, except that Oracle has automated tests.

(ASML makes machines that make chips. They got something like 90% of the market. Intel, Samsung, TSMC etc are their customers)

ASML has 1 machine available for testing, maybe 2. These are machines that are about to be shipped, but not totally done being assembled yet, but done enough to run software tests on. This is where changes to their 20 million lines of C code can be tested on. Maybe tonight, you get 15 minutes for your team's work. Then again tomorrow, if you're lucky. Oh but not before the build is done, which takes 8 hours.

Otherwise pretty much the same story as Oracle.

Ah no wait. At ASML, when you want to fix a bug, you first describe the bugfix in a Word document. This goes to various risk assessment managers. They assess whether fixing the bug might generate a regression elsewhere. There's no tests, remember, so they do educated guesses whether the bugfix is too risky or not. If they think not, then you get a go to manually apply the fix in 6+ product families. Without automated tests.

(this is a market leader through sheer technological competence, not through good salespeople like oracle. nobody in the world can make machines that can do what ASML's machines can do. they're also among the hottest tech companies on the dutch stock market. and their software engineering situation is a 1980's horror story times 10. it's quite depressing, really)

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#548

Post by pmarreck »

vaylian wrote: post #493
pmarreck wrote: post #222

Earlier quoted context omitted.

Since when is a greenfield app on a new product addressing a market with only old entrenched players “throwing away your sanity?”

Sorry, I did not realize you meant to create a new software from scratch. I thought you were talking about supporting/extending/refactoring this old pile of madness. Thanks for the clarification! I suppose you were referring to the statement "Customers in that space don't have many options". Your statement is reasonable and there might be market opportunities to create new software. But I somehow have the feeling tha…

Thing is, a competing product does not (at launch) have to match the entrenched one feature-for-feature. It just has to tick the MOST IMPORTANT boxes while being advantageous in other ways (such as being built on FAR newer tech, more reliable etc.)

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#549

Post by dlandi »

oraguy wrote: post #18

Oracle Database 12.2. It is close to 25 million lines of C code. What an unimaginable horror! You can't change a single line of code in the product without breaking 1000s of existing tests. Generations of programmers have worked on that code under difficult deadlines and filled the code with all kinds of crap. Very complex pieces of logic, memory management, context switching, etc. are all held together with thousand…

#JobSecurity

Re: Ask HN: What's the largest amount of bad code you have ever seen work?

#550

Post by guscost »

Blaisorblade0 wrote: post #545
guscost wrote: post #531

Earlier quoted context omitted.

How would you know that merging code from the first bugfix wouldn't break the (just tested) code from the second bugfix?? Would you assume that the first bugfix will be merged first and branch off of that?

Without knowing Oracle's approach, this sort of problem is no different from any other software, even tho it reaches a larger scale. Branch from master, and rerun tests before the final merge, like you should in any other software? (Many processes fail that criterion, see https://bors.tech/ for something that gets this right). Ideally you work on a different enough bug that there's limited interaction, and ideally th…

But if the time needed to test and deploy a change is so ludicrous, it seems like you'd rarely get a big-enough window to rerun your tests before the upstream changes again. Either people are merging in unstable code, or the release lifecycle is a slow byzantine nightmare too (probably the case here).
Post reply on HN