The Cults of TDD and GenAI

https://drewdevault.com/blog/Cult-of-TDD-and-LLMs/

by pards • 3 months ago

5 8 3 months ago

pards4• 3 months ago

A few quotes that resonated with me:

it (TDD) makes you feel like a good programmer even if none of it necessarily contributes to the results your team is supposed to achieve.

It also, in my experience, often makes refactoring difficult because the implementation is set in stone, not the behaviour. I know the TDDers say this is because the tests are bad but, like agile, very few people seem to be able to "do it right".

All of the really hard problems are not solved by TDD.

I've never seen TDD iterate towards good architecture. It optimizes for testable logic.

A coding agent permits one to feel as if they have the raw productive power a great programmer can tap into. [...] Those cathedrals are not the great works they appear to be. The construction is shoddy and the architecture nonsensical

In other words, AI allows junior/mediocre devs to _feel_ experienced and produce naive implementations much faster, burying the experienced devs in the drudgery of code reviews and defect triage.

rvz• 3 months ago

If you're a startup and religiously using TDD from the very beginning without focusing on your core product and have little to no revenue coming in, you are wasting your time.

Once you have the revenue / funding and the paying customers then having TDD with thousands of tests makes a lot more sense.

I'm very hesitant to use an agent to completely generate lots tests unless you clearly know what to test for. Otherwise I write them myself.

pards4• 3 months ago

using TDD [...] without focusing on your core product

This. Even in large enterprises, I've seen projects prioritize code metrics over product metrics. A beautiful codebase that nobody uses is completely wasted effort.

pydry2• 3 months ago

I swear almost every critique of test driven development boils down to "I wrote a bad test".

Yet TDD has no opinion on how you design your tests. There are people who say "you must do DI if you do TDD" or "TDD must be done with unit tests" and they are wrong but that is a separate conversation.

The author seems to disagree arguing that TDD is "pressuring" him to write tests in a certain way. Bull. He made a choice.

Invariably the shitty test which you write before because you overdid low level unit testing or DI is going to be just as shitty written after the code. Maybe a hint that PEBKAC?

It’s an intoxicating way to work, especially for someone who struggles with software engineering. It makes you feel like a good programmer

I think somebody needs to get allll the way over themselves.

pards4• 3 months ago

For clarity, PEBKAC is "problem exists between keyboard and chair"

pards4• 3 months ago

In my experience, the level of test coverage has little to no correlation to the quality and readability of the codebase.

These are subjective, of course, but some of the easiest codebases to understand had low test coverage, and some of the most complex codebases had high test coverage. The opposite has also been true.

voiceofunreason• 3 months ago

I swear almost every critique of test driven development boils down to "I wrote a bad test".

It does seem that way - this one theme does drown out all of the other criticisms.

That said, (to first order) everyone's been "doing it wrong" for 25 years (give or take, there are lots of reasonable start dates to choose from).

Maybe "everyone" isn't the actually the problem, and we need to be open to alternatives like "our theory of what makes it work isn't very strong yet", "we oversold it", or "it was only ground breaking when compared with just-winging-it".

pydry2• 3 months ago

There are cultural reasons why shitty testing practices have persisted for ~30 years but those practices suck equally badly whether you do them with TDD or without TDD.

TDD is a scapegoat.

The Cults of TDD and GenAI

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