[ddavis]

I agreed with this 100% for a long time. Then I started working on a library at $WORK with dozens of downstream users abusing the hell out of my idiomatic underscore usage, especially in the context of lazy tests with folks writing endless mocks. When I’d “break” their test suite (blocking some time sensitive release) I’d get all kinds of shit. But _they_ were breaking the contract. Unfortunately I had little (if any) control on the path of application code making it to production (yeah yeah not great engineering org, but it’s the world I lived in). Strategies like this post would be helpful for said situations.

[senkora]

There’s always the extra idiomatic __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED for coworkers that can’t take a hint.

https://github.com/reactjs/react.dev/issues/3896

[nomel]

You can technically "enforce" this at runtime with __getattribute__ or decorators[1].

Maybe be evil and add 1000 "Private access not allowed: {name}" with 1 second delays between each.

Aaaand, this flexibility is exactly why python is slow.

[1] https://pypi.org/project/accessify/

[taeric]

I'm torn. On the one hand, this is not too uncommon of a problem to run into. On the other, poor practices from coworkers are not going to go away thanks to a language filter.

So, the question will come down to which causes more grief, people abusing this convention, or people that overly use the language features that combat it? It is the standard optimization question between poor practices and enforcement that you have in any question of enforcement.

I would be delighted if we could get some empirical data on this.

[sanderjd]

I generally agree with you (and disagree with the parent comment) that I think this seems like a useful technique. But just note that if someone really wants to break the contract, they can just use the "private" class. Just like "private" members, it is only private by convention.

[david-gpu]

> Then I started working on a library at $WORK with dozens of downstream users abusing the hell out of my idiomatic underscore usage [...]. When I’d “break” their test suite [...] I’d get all kinds of shit

I can understand this happening once. But, after that, management should have been involved and addressed the root problem. It would be no longer a technical or communication issue, but a project management one.

[1-more]

My secret for test-only code is to provide functions whose first argument is a value that only exist in a test scenario. There are also static analysis rules for the linter in my language of choice that disallows test-only functions being called outside of test files. This gets you closer to "we're actually adults here" but still a tiny bit cheatable.

[jghn]

Something similar happened to me. I told those groups to pound sand because they knew they were relying on something which they should not. Manager had my back, they whined a lot but they had to change and improve their processes.