Double assignment is still needed to prevent an "unused variable" warning

[kamipo]

That warning is still raised on latest Ruby.

% bundle exec ruby -w -Itest test/spec_show_exceptions.rb test/spec_show_status.rb
/Users/kamipo/src/github.com/rack/rack/lib/rack/show_exceptions.rb:66: warning: assigned but unused variable - path
/Users/kamipo/src/github.com/rack/rack/lib/rack/show_exceptions.rb:68: warning: assigned but unused variable - frames
Run options: --seed 23328

# Running:

........

Finished in 0.240203s, 33.3052 runs/s, 374.6831 assertions/s.

8 runs, 90 assertions, 0 failures, 0 errors, 0 skips

% bundle exec ruby -w -Itest test/spec_show_status.rb
/Users/kamipo/src/github.com/rack/rack/lib/rack/show_status.rb:26: warning: assigned but unused variable - req
/Users/kamipo/src/github.com/rack/rack/lib/rack/show_status.rb:30: warning: assigned but unused variable - detail
Run options: --seed 41036

# Running:

.......

Finished in 0.061453s, 113.9082 runs/s, 829.9025 assertions/s.

7 runs, 51 assertions, 0 failures, 0 errors, 0 skips

[ioquatix]

Thanks for this I will check it.

[ioquatix]

This is because of ERB and using binding.

Maybe another solution is to pass a hash of the relevant variables into ERB.

I don't know a lot about ERB, but this is the approach I use in Trenni (similar to ERB) in my own projects.

[kamipo]

I already tried that, ERB#result_with_hash which is introduced at Ruby 2.5 uses TOPLEVEL_BINDING, but in this case we need to use local binding object to use h helper in the ERB template.

[ioquatix]

@mame do you have any suggestions about how we can improve this?

[ioquatix]

I've merged this because I agree we don't want warnings. But maybe there is a better way.

[mame]

🤔

@nobu What do you think?