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

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

#561

Post by bullshitman »

kazinator wrote: post #472
acroback wrote: post #415

Earlier quoted context omitted.

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…

The problem with TDD is that the methodology wants to cover every change, no matter how internal, with some sort of external test. Some changes are simply not testable, period. No, you cannot always write a test which initially fails, and then passes when the change is made, and when this is the case. You should understand why that is, and not try. In some cases when you can , yet still should not. If a whole module…

Bullshit. Even if you say "period", it doesn't make a bullshit true.

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

#562

Post by bullshitman »

astrange wrote: post #456
ddfx wrote: post #431

Earlier quoted context omitted.

I think TDD is the best way to develop (yet). Obviously tests are code, and if you write crappy highly-coupled tests you will end up with only much more messy code. This is a clear example of bad testing. The greatest advantage of TDD is in design, everything should be modular and easy to unit test, so you could: - reproduce bug and verify your bugfix in matter of ms with proper unit test - understand what code does…

A unit test is the least useful kind of test. It requires your design to be "easy to unit test" instead of simple, and if you change something and have to rewrite the test you might miss some logic in both pieces. Plus the tests never break on their own because they're modular, and each time you run a test that was obviously going to pass, you've wasted your time. As long as you have code coverage, better to have lot…

Bullshit. I have found many bugs writing unit tests to a legacy code (afterwards). I have cleaned up incredibly messy spaghetti code by writing unit tests (which forced me to clean it up). I have made the code understandable by writing unit tests (both by means of "test as a documentation" and by means of "clean the code so that it is testable, make it modular and made of small units").

And btw, "easy to unit test" actually leads to "simple". That's the point of TDD.

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

#564

Post by troels »

pgaddict wrote: post #534
forthy wrote: post #498

Earlier quoted context omitted.

I doubt the competition (e.g. IBM or Microsoft) has any better code quality. Even PostgreSQL is 1.3M lines of code, so let's get something deliberately written for simplicity. SQLite is just 130k SLoC, so another order of magnitude simpler. And yet, even SQLite has an awful amount of test cases. https://www.sqlite.org/testing.html

I'm sure some of the difference (25M vs. 1.3M) can be attributed to code for Oracle features missing in PostgreSQL. But a significant part of it is due to careful development process mercilessly eliminating duplicate and unnecessary code as part of the regular PostgreSQL development cycle. It's a bit heartbreaking at first (you spend hours/days/weeks working on something, and then a fellow hacker comes and cuts of th…

> It's a bit heartbreaking at first (you spend hours/days/weeks working on something, and then a fellow hacker comes and cuts of the unnecessary pieces), but in the long run I'm grateful we do that.

The single hardest thing about programming, I'd say.

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

#565

Post by royaltm »

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…

I wonder what version control system do they use for that monstrosity (how long it takes to checkout/commit changes)?

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

#566

Post by [deleted] »

theshrike79 wrote: post #254
gnulinux wrote: post #49

Earlier quoted context omitted.

Tests that run for 30 hours is an indication that nobody bothered writing unittests. If you need to run all tests after changing X, it means X is NOT tested. Instead you need to rely on integrations tests catching Xs behavior.

In large systems you can unit test your code within an inch of its life and it can still fail in integration tests.

[deleted]

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

#567

Post by kaon »

theshrike79 wrote: post #254
gnulinux wrote: post #49

Earlier quoted context omitted.

Tests that run for 30 hours is an indication that nobody bothered writing unittests. If you need to run all tests after changing X, it means X is NOT tested. Instead you need to rely on integrations tests catching Xs behavior.

In large systems you can unit test your code within an inch of its life and it can still fail in integration tests.

Exactly. I have a product that spans multiple devices and multiple architectures: micro controllers, SDKs and drivers running on PCs, third-party devices with firmware on them and FPGA code. They all evolve at their own pace, and there’s a big explosion of possible combinations in the field.

We ended up emulating the hardware, run all the software on the emulated hardware, and deploy integration tests to a thousand nodes on AWS for a few minutes it takes to test each combination. Tests finish quickly and it has been a while since we shipped something with a bug in it.

But there’s a catch: we have to unit test the test infrastructure against real hardware - I believe it’d be called test validation. Thus all the individual emulators and cosimulation setups have to have equivalent physical test benches, automated so that no human interaction is needed to compare emulated output to real output. In more than a few cases, we need cycle-accurate behavior.

The test harness unit (validation ) test has to, for example, spin up a logic analyzer and a few MSO oscilloscopes, reinitialize the test bench – e.g. load the 3rd party firmware we test against, then get it all synchronized and run the validation scenarios. Oh, and the firmware of the instrumentation is also a part of the setup: we found bugs in T&M equipment firmware/software that would break our tests. We regression test that stuff, too.

All in all, a full test suite, run sequentially, takes about 40,000 hours, and that’s when being very careful about orthogonalizing the tests so that there’s a good balance between integration aspects and unit aspects.

I totally dig why Oracle has to do something like this, but on the other hand, we have a code base that’s not very brittle, but the integration aspects make it mostly impossible to reason about what could possibly break - so we either test, or get the support people overwhelmed with angry calls. Had we had brittle code on top of it, we’d have been doomed.

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

#568

Post by kaon »

christophilus wrote: post #335
dejv wrote: post #168

I am maintaining one application in construction industry space. That application was created 25 years ago by construction worker that never wrote single line of code before, but because he caused a lot of problems on construction site they give him Programming 101 book and let him build it. 15 years later the app was close to half milion lines long of huge bowl of spaghetti code. Only comments in whole codebase were…

One of my first jobs in the industry was really similar. I ended up sitting down with a friend and rewriting it in C#. We didn’t have permission, but no one knew until our codebase was already in working shape (a month or so). We got away with it because the original codebase was so bad that it hadn’t shipped in 5 years. Months of 0 productivity were normal. My friend and I went on to rewrite the entire suite of prod…

We had a bunch of code at work that everyone sort of begrudgingly used that I wrote almost 20 years ago, not knowing too much about what I was doing. I have recently rewritten it – about 100kLOC of messy C++ turned into 25kLOC of bliss. The test coverage we had ensured that we didn’t have to worry about anything breaking. I hate myself a bit less :)

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

#569

Post by UziTech »

My first PHP app was an invoicing application. It is ~3500 lines of php in a single file. Most of which is a few heredocs with javascript to be in lined on the client side. I haven't touched the code in 10 years. I still use it for my freelance invoicing.

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

#570

Post by p0nce »

Latteland wrote: post #555
p0nce wrote: post #522

Earlier quoted context omitted.

It's because software LOC scales linerarly with the amount of man-months spent: a testament to the unique ability of our species to create beautiful, abstract designs that will stand the test of time.

This is an interesting comment, because I can't decide if you are sarcastic or making a deep insightful comment. Because I don't think the statement is true. LOC can go on forever, but it usually happens in things that aren't beautiful and abstract.

I was being sarcastic.
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