`--fix` causes `);` or `) is` to be appended to comment instead of code with `last_close_paren: remove_new_line`

[lois-bosson-enclustra]

Hello,
First of all, thanks a lot for the great work on VSG!
I've encountered an unexpected behavior which structurally breaks code when using --fix in the following situation:

Environment
OS: Windows 11
VHDL Style Guide (VSG) version: 3.35.0
Shell: Git Bash

Describe the bug
Using the following rules.yaml file:

rule:
    procedure_013:
        last_close_paren: remove_new_line

and the following package.vhd:

package pkg is

  procedure proc (
    arg : natural -- Here:
  );

end package pkg;

package body pkg is

  procedure proc (
    arg : natural -- And here:
  ) is

  begin

    null;

  end procedure proc;

end package body pkg;

Running the command:
$vsg -f package.vhd -c rules.yaml --fix

Moves both ); and ) is to the end of the previous line, that is in the comment block, yielding:

package pkg is

  procedure proc (
    arg : natural -- Here:);

end package pkg;

package body pkg is

  procedure proc (
    arg : natural -- And here:) is

  begin

    null;

  end procedure proc;

end package body pkg;

Expected behavior
The closing parentheses should be moved to the end of the "code portion" of the line, and not in the comment:

package pkg is

  procedure proc (
    arg : natural); -- Here:

end package pkg;

package body pkg is

  procedure proc (
    arg : natural) is -- And here:

  begin

    null;

  end procedure proc;

end package body pkg;

Let me know if you can reproduce it or if you need anything else!

Best regards,

Loïs

[JHertz5]

Hi @lois-bosson-enclustra. Thanks for raising this issue and for providing thorough details about the problem. I can recreate the issue and I'll look into it to see whether I can find a fix.

[JHertz5]

Hi @lois-bosson-enclustra

I'm still looking into this - I've figured out the cause of the problem and have made some progress to solving the issue, but I've hit a difficult problem. I've got the rule fixed so that it will move a comment on the final line of the parameter list to the end of the rule violation's token list when making the correction. However, that produces the following:

package pkg is

  procedure proc (
    arg : natural )-- Here:;

end package pkg;

package body pkg is

  procedure proc (
    arg : natural )-- And here: is

  begin

    null;

  end procedure proc;

end package body pkg;

You'll notice that the problem isn't fully solved, the ; or is is still after the comment. This is because those tokens are outside the scope of tokens that are visible to the rule.

I have an idea on how to fix this though. I've tried and it would really be difficult to expand the scope of the rule to include the token after the ). However, I've had an idea. My plan is basically to run a check when a violation is fixed to validate that any comments are at the end of their respective lines, and to move them to the end of the line if not. I'm quite busy at the moment, so not sure when I'll be able to implement this, but I'll hopefully have another update for you within the next couple of weeks.

[lois-bosson-enclustra]

Hello @JHertz5

Thanks for having a look and giving an update. So if I understand correctly, you'd store the comment from the previous line and then check after fixing? I must admit I am not really familiar with the vsg internals, but I'd be tempted to instead strip the comments, apply the changes and append the comments again at the end of the line and sidestep the checking. I can imagine that could create issues with comment rules however, so I defer to your expertise here.
By the way, I very much appreciate you looking into this and want to emphasize that I am no waiting for a fix or anything, just hoping to help make the tool more resilient. Best of luck for when you find the time!