I have personally worked on a team where velocity collapsed under the weight of the test suite.

There were lots of brittle mocks. I think we even did mock out the Ruby equivalent of the HTTP client.

Every change would inevitably break tests (not functionality!) and developers were spending more than half their time wrestling with the test suite.

All of us could have used this article.

Please always strive to improve your practice. Commit things that aren’t perfect, but try to internalize best practices over time. Gradually raise your own code quality bar as you get better.

Learning from posts like the OP is super important if you don’t have a good senior Eng on your team. A group of smart juniors can easily code themselves into a hole of left to their own devices. I know this, because I did this.

FWIW I’m a former senior-less junior that programmed himself into a hole. My blog and conference talks are exactly the material that I’d loved to have had ~10 years ago.

Not sure if I’d have been smart enough to take my advice though. ;)

>Every change would inevitably break tests (not functionality!) and developers were spending more than half their time wrestling with the test suite.

I find that this invariably happens because the team tries to test implementation at a very low level rather than behavior at a high level.

I blame an overemphasis on unit tests over integration testing (e.g. J B Rainsberger's inane rant) and tutorials that imply that, for example, if you build a class you have to have some tests for that class.

At a previous company, someone established a "rule" that every "new function or method" needed its own test. Unless you lucked out with a lax reviewer (like me!) , your code would not pass review if this wasn't followed. Meanwhile, there were basically zero integration or e2e tests. People spent more time adding and maintaining useless tests...

These sound like checksum tests. If you touch anything, they fail. That's all they do now, alert you that yes, you touched that code, now go figure the new checksum for the next poor soul.

Agreed. One thing Juniors don't get (and some seniors) is when to test. I see them writing tests on business logic and have to correct them regularly. I've had to sit down and explain to 3rd party technical resources that they're foolishly asking for more technical debt by asking for certain tests.

The other thing Juniors don't get is prototyping. I regularly build something quickly to get the problem set into my head. If it's good enough, I'll leave it. If it's got issues, I'll throw it away and start fresh now that I know what I'm solving. Juniors don't work fast enough or effective enough to do things like that without putting timelines at risk. Plus, they frequently want to do some cargo cult methodology of the week like TDD.

> I see them writing tests on business logic and have to correct them regularly.

Are you saying you have to tell the developers not to test business logic, or that you have to fix the tests they write?

The former. Business logic changes regularly. New phases of projects frequently require changes that break the unnecessary business logic test code.

Test code should fail when an important underlying mechanism regresses. If it always fails on the next phase of the project because some hapless idiot needed to cover every line, the signal to noise ratio gets weaker and the purpose of the test code is lost.

Thanks for the clarification -- that's what I suspected, but thought I must be misreading or misunderstanding, but I also don't know your situation and trust you're making the right set of trade-offs here. If your system is today a cuttlefish, yesterday a cow, and tomorrow a crab, cow tests don't do you much good. That sounds like a crazy environment, and I'd maybe have a care that those hapless idiots are sane people in an insane place.

You sound like you're in that category if you can't differentiate and think that it's surprising for software to have a flexible business logic layer.

Counterpoint, I've not seen seniority affect these outcomes at all. Most of the time I see some management type or CTO heavily push the "code coverage / test everything" narrative which then rolls down the hill. Strategy did not seem at all correlated with seniority.

Same goes for prototyping. I don't see much of a correlation between willingness to prototype and seniority, either.

I worked at a place that had a "increase test coverage" dogma. If you ran out of real work, which was common due to poor management, you'd wind up with an awful "increase test coverage to 80%" ticket to keep you busy. This resulted in at least one guy quitting because he said it was a useless waste of time.

I can assure you that it is possible and meaningful to have full code coverage in certain contexts (for instance for important projects that get only rarely touched) and doesn’t inevitably lead to bad test suites.

Railing against code coverage is at this point just as dogma as insisting on it.

Not sure why you're highlighting this in a sub-thread regarding the importance of context. Surely this was already implied?

What I'm railing against is the idea that seniority is a prime indicator to the effective strategy parent comment insists on, which simply doesn't mirror my experiences. What I see is juniors picking up the habits of their superiors. They're learning this dogmatism from somewhere.

I’m sorry I’ve apparently misunderstood your point. I guess I’ve never seen too brass imparting more than a big picture “we’re writing tests now”.

Depends on the industry and client. Some industries have a lot of consultants that don't write code but will tell you 80% is the minimum. Some contracts stipulate code coverage deliverables. Some platforms like Salesforce count lines of code covered and prevent deployments unless 75% and passing.

> Same goes for prototyping. I don't see much of a correlation between willingness to prototype and seniority, either.

Willingness is one thing, but getting yelled at for learning and doing your best is another. I never treat my Juniors like that, and encourage a 75/25 working/improving split. Still, several frequently get anxiety about how long it's taking them to clear tickets.