7 ms·

Forgive my ignorance, but why and how would you test a comment? They don't do anything, there is no instruction for the machine to understand or run.

ttty 12y ago
Then you will read the comment that says to do one thing but the program will do a completely other thing. I don't see any problem, do you?
- mike_hearn 12y ago
  That's why good comments are about explaining WHY you're doing something, or HOW to use the code, and possibly making the code itself clearer but only if there's no way to do that by introducing better variable and method naming. Comments are highly valuable but like any tool they can be abused, or done in such a way that they don't make things better.
  - wtetzner 12y ago
    The point is that comments can become out of date, and there's no automated way to enforce they stay up to date.
knowaveragejoe 12y ago
He's referring to the problem of comments becoming out of sync with the code they're referring to. Not everyone updates comments as they update code.
- jdbernard 12y ago
  And those people deserve a special place of torment all their own. How hard is it really to update, or at least delete comments that are no longer relevant when you modify the code?
  - knowaveragejoe 12y ago
    It's not that it's hard, it just may not be apparent that you need to do so.
seanmcdirmid 12y ago
The comments are meant to be read and used to understand code. So you must test them like any other artifact to ensure that they are a net positive and not a net negative. Programmers make mistakes, which hopefully fail a test or at least cause a crash. Because comments can't be executed, neither of those will happen; they have to be verified manually
- AlisdairO 12y ago
  Isn't that fairly easy to do during a code review?
  - seanmcdirmid 12y ago
    Sure, code review is a very manual approach.
    - AlisdairO 12y ago
      Yes, what I mean is, if you're doing code review then there's virtually no additional cost - you're looking over the changes anyway. It doesn't matter that the process is manual if you're already doing it. If you're not doing code review, then you perhaps either have some organisational issues or you have coworkers who are sufficiently responsible that you can trust them to do basic code hygiene work like keeping comments up to date.
      - seanmcdirmid 12y ago
        I think comments would be more difficult to review than code, since you'd have to carefully make sure they are meaningful by examining the code, without the context of the programmers involved. Alternatively, you could add comments during code review to document the review and basically redo the comments on each review...maybe. Comments also break flow and get in the way of code reading, but could probably just be hidden during review.
        dragonwriter 12y ago
peaton 12y ago
Brings up an interesting point about perhaps using natural language processing to determine correctness of a comment. That would be prettty cool.
- kedean 12y ago
  If you could use NLP to verify the comment, then what would the point of the comment be? Comments are for those aspects of a program that are invisible to the compiler and IDE, the intent.
  - peaton 12y ago
    Maybe my view of NLP is more sci-fi than reality, but I think you're missing what I meant. If you can use NLP to prove that your comment - ie the intent - which IS invisible to the compiler and IDE, then that might be cool. Practical, probably not. But I'd still be very impressed at the implications if this was possible within some error margin.

ttty 12y ago

Then you will read the comment that says to do one thing but the program will do a completely other thing. I don't see any problem, do you?

mike_hearn 12y ago
That's why good comments are about explaining WHY you're doing something, or HOW to use the code, and possibly making the code itself clearer but only if there's no way to do that by introducing better variable and method naming. Comments are highly valuable but like any tool they can be abused, or done in such a way that they don't make things better.
- wtetzner 12y ago
  The point is that comments can become out of date, and there's no automated way to enforce they stay up to date.

knowaveragejoe 12y ago

He's referring to the problem of comments becoming out of sync with the code they're referring to. Not everyone updates comments as they update code.

jdbernard 12y ago
And those people deserve a special place of torment all their own. How hard is it really to update, or at least delete comments that are no longer relevant when you modify the code?
- knowaveragejoe 12y ago
  It's not that it's hard, it just may not be apparent that you need to do so.

seanmcdirmid 12y ago

The comments are meant to be read and used to understand code. So you must test them like any other artifact to ensure that they are a net positive and not a net negative. Programmers make mistakes, which hopefully fail a test or at least cause a crash. Because comments can't be executed, neither of those will happen; they have to be verified manually

AlisdairO 12y ago
Isn't that fairly easy to do during a code review?
- seanmcdirmid 12y ago
  Sure, code review is a very manual approach.
  - AlisdairO 12y ago
    Yes, what I mean is, if you're doing code review then there's virtually no additional cost - you're looking over the changes anyway. It doesn't matter that the process is manual if you're already doing it. If you're not doing code review, then you perhaps either have some organisational issues or you have coworkers who are sufficiently responsible that you can trust them to do basic code hygiene work like keeping comments up to date.
    - seanmcdirmid 12y ago
      I think comments would be more difficult to review than code, since you'd have to carefully make sure they are meaningful by examining the code, without the context of the programmers involved. Alternatively, you could add comments during code review to document the review and basically redo the comments on each review...maybe. Comments also break flow and get in the way of code reading, but could probably just be hidden during review.
      - dragonwriter 12y ago

peaton 12y ago

Brings up an interesting point about perhaps using natural language processing to determine correctness of a comment. That would be prettty cool.

kedean 12y ago
If you could use NLP to verify the comment, then what would the point of the comment be? Comments are for those aspects of a program that are invisible to the compiler and IDE, the intent.
- peaton 12y ago
  Maybe my view of NLP is more sci-fi than reality, but I think you're missing what I meant. If you can use NLP to prove that your comment - ie the intent - which IS invisible to the compiler and IDE, then that might be cool. Practical, probably not. But I'd still be very impressed at the implications if this was possible within some error margin.