Panic in footer() with empty table

[gtunes-dev]

Thank you for this crate!

footer() panics in the case where no rows have been written and borders and padding are left at defaults.

It happens here (currently line 475):

        let border_width = if self.borders { 1 } else { 0 } + if self.padding { 1 } else { 0 };
        let foot_width = self.width - (border_width * 2);

In this case, self.width is stil 0, border_width becomes "1" becoming:

let foot_width = 0 - (1 * 2) // panic - attempt to subtract with overflow
finish() doesn't panic for obvious reasons - but does print what amounts to an empty line.

I sort of hoped that in the case of no printed rows, I would be able to print an empty table or even a table with a "No data" row or something like that. I'm not sure how useful this is, though. I think it's probably worth fixing the panic, though.

Thanks!

[NfNitLoop]

Thanks for the bug report! You're the first bug from someone who's not me! 😊 I definitely don't want to panic, so I'll try to fix this. If I haven't fixed it in a week please feel free to ping me to remind me.

[gtunes-dev]

You're welcome! I appreciate you sharing it!

[gtunes-dev]

I forked your repo and fixed the issue, though my fix is a breaking behavioral change. Because of this, I'm not going to submit a PR.

I added a small feature that allows the user to set an "empty_row" which gets rendered if the table is finished or footered without any rows having been written. This means that, in these cases, I am also intentionally printing the headers.

This empty row is printed using the same centering strategy you use for title and footer.

I also modified finish and footer to return the width of the table. This is useful to me because I print other content after the table and want to use it to create my own hr equivalent based on it. It might be interesting for you to add it, too, since I don't believe there's any downside and it's non breaking.

My fork is here if you're interested in what I did: https://github.com/gtunes-dev/tablestream/

This is a super useful piece of code you shared. Thank you!