This is a good point, and I'm not arguing with it, but I don't think the words "code cannot lie" are the right way to express it.

Code can deceive even if, definitionally, the code states what the computer will do. So code most certainly can lie.

[By analogy, you'd still feel lied to if someone told you something that is technically correct but very misleading: "(Me) It's going to rain tomorrow." → tomorrow comes → "(You) It isn't raining today!" → "(Me) It is raining, in Japan. I didn't say it would rain here."]

I suppose it depends on whether you're considering what the code communicates to the machine or what it communicates to a person.

How about "code does what it does but comments say what it might have once, and possibly still might do?"

You can have your pipeline regression test code, but not comments. Just recently my mentee found some of my code where I had changed the code but not the comment. I'm a horrible human and wasted his time. If that comment hadn't existed the code might have taken a moment to understand but as it was, he wasn't sure which was the intent.

While code gives you a correct understanding of the state of the system, it doesn't give you any understanding of why the system is in that state. That's the point from the OP. Code tells you what a system is doing, not why it was designed to be that way. Comments that try and explain what a system is doing can absolutely be wrong and therefore problematic, but there's no way for code to convey the context in which it was implemented a particular way, which is what comments are for.

Code without comments only gives half the story. It gives you the what, not the why.

> Code cannot lie

Sure, but it can take you on a freaking trip. Comment your code bro.

This whole argument makes me think of C coders who say C is perfectly safe as long as you don’t write bugs.

The point is not to fetishize comments. Write a comment if you feel something needs explanation, but don't freak out about "uncommented code" as a smell or whatever, when reading the code should have been your first step anyway.

And to repeat: when debugging, train yourself to ignore the comments. They will absolutely lie to you.

Imo comments are like formatting. If you don’t enforce it in CI it’s going to be bad

Forcing developers to write comments[1] just to get code merged seems like the best possible way to ensure those comments are lies.

[1] Which, it's important to point out since you used the term "CI", are fundamentally untestable. There's absolutely no way to ensure a comment is correct. A CI smoke test at the very least verifies code builds and doesn't break pre-existing cases. No such validation is even theoretically possible for comments.

I’ve seen it done before and no, it was beautiful, everything was commented