show valid break point lines

[ko1]

This PR is for usability. Show valid break point lines when break command fails.

Like that:

$ bin/byebug ~/src/rb/t.rb --
/home/ko1/src/rb/byebug/lib/byebug/helpers/bin.rb:15: warning: Insecure world writable dir /home/ko1/src/rb/byebug in PATH, mode 040777

[1, 10] in /home/ko1/src/rb/t.rb
    1:
=>  2: p 0
    3:
    4: def foo
    5:   if false
    6:     return 1
    7:   else
    8:     return 2
    9:   end
   10: end
(byebug) b 5
*** Line 5 is not a valid breakpoint in file /home/ko1/src/rb/t.rb.
Valid break points are:
[B]  2: p 0
     3:
[B]  4: def foo
     5:   if false
     6:     return 1
     7:   else
[B]  8:     return 2
     9:   end
[B] 10: end
    11:


(byebug)

It is hard to find out which lines are valid or not.
I'm not sure it is correct way to output messages, but please consider this idea.

Thanks,
Koichi

[deivid-rodriguez]

@ko1 Thanks so much, this is a great usability improvement indeed! I added some extra changes so that byebug linters and tests are happy, but it looks great. This will be released with the next version! ❤️

[deivid-rodriguez]

I'll probably add a few extra changes so that the surrounding code respects the user's listsize setting, but this is going in anyways!

[ghost]

This probably sounds like a dumb question... I've cloned the latest byebug-master from GitHub. How do I build/install it? I'm used to 'gem install' but that's about it...

TIA.

[MSP-Greg]

@stevewi

There may be an easier way, but normally I do the following, which does give you a gem file in case whatever...

From the repo folder:

1. gem build byebug,gemspec
2. gem install -l byebug-9.1.0.gem (version may change)

Reference - RubyGems 2.7.4 Command Reference, same info several places on the web...

[deivid-rodriguez]

@stevewi Does your application have a Gemfile? In that case, you can also add byebug to that file specifying this: gem "byebug", git: "https://github.com/deivid-rodriguez/byebug", and then run bundle install. Then run any command inside your application folder prefixed with bundle exec.

[ghost]

My app does have a Gemfile but I also use byebug to debug one-off's and test jigs. I installed the current master as a local gem using the method MSP-Greg described above. When all this gets resolved, I'll install byebug as a global gem again.

The only other thing I had to change on one system is a modification to my PATH on one Linux system to include $HOME/.gems/bin. My problem, not yours :-)

Thanks!