Dynamic formatter configuration broken (v0.36)

[agross]

I define my formatters dynamically in my Rakefile to get different output when the check runs on a developer machine vs. a build machine.

This used to work in v0.35.1:

RuboCop::RakeTask.new(:rubocop) do |t|
  t.formatters = %w(files)
  t.formatters << %w(html --out build/rubocop/rubocop.html)
end

And with v0.36 is fails with an error:

$ bundle exec rake rubocop
Running RuboCop...
no implicit conversion of Array into String
C:/Ruby/lib/ruby/2.2.0/optparse.rb:378:in `match'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:378:in `parse_arg'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:531:in `parse'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1395:in `block in parse_in_order'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1383:in `catch'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1383:in `parse_in_order'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1377:in `order!'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1469:in `permute!'
C:/Ruby/lib/ruby/2.2.0/optparse.rb:1491:in `parse!'
C:/Ruby/lib/ruby/gems/2.2.0/gems/rubocop-0.36.0/lib/rubocop/options.rb:18:in `parse'
C:/Ruby/lib/ruby/gems/2.2.0/gems/rubocop-0.36.0/lib/rubocop/cli.rb:24:in `run'
...

I added some debug output before options.rb:18 (puts args.inspect):

["--format", "files", "--format", ["html", "--out", "build/rubocop/rubocop.html"]]

[alexdowad]

t.formatters is an array of strings, not an array of arrays of strings.

You can use t.formatters.concat(%w(html --out build/rubocop/rubocop.html)).

Maintainers, please close.

[agross]

Maintainers, please do not close.

@alexdowad The problem with concat is that rubocop prepends --format in front of every array element.

RuboCop::RakeTask.new(:rubocop) do |t|
  puts RuboCop::Version.version
  t.formatters = %w(files)
  t.formatters.concat(%w(html --out build/rubocop/rubocop.html))
end

rubocop v0.36:

$ bundle exec rake rubocop
0.36.0
Running RuboCop...
["--format", "files", "--format", "html", "--format", "--out", "--format", "build/rubocop/rubocop.html"]
No formatter for "--out"
C:/Ruby/lib/ruby/gems/2.2.0/gems/rubocop-0.36.0/lib/rubocop/formatter/formatter_set.rb:84:in `builtin_formatter_class'
C:/Ruby/lib/ruby/gems/2.2.0/gems/rubocop-0.36.0/lib/rubocop/formatter/formatter_set.rb:56:in `add_formatter'
...

rubocop v0.35.1:

$ bundle exec rake rubocop
0.35.1
Running RuboCop...
["--format", "files", "--format", "html", "--format", "--out", "--format", "build/rubocop/rubocop.html"]
No formatter for "--out"
C:/Ruby/lib/ruby/gems/2.2.0/gems/rubocop-0.35.1/lib/rubocop/formatter/formatter_set.rb:93:in `builtin_formatter_class'
...

[alexdowad]

@alexdowad The problem with concat is that rubocop prepends --format in front of every array element.

OK. Thank you for pointing this out. In that case, you can use t.options instead.

t.formatters is just a shortcut for adding strings with --format prepended to options. It is intended to receive an array of strings, each of which is a formatter name.

[alexdowad]

@agross Is your problem resolved?

[agross]

@alexdowad I'm waiting for feedback of the maintainers. I'd like to learn how they think about my approach that was valid for 0.35.1, but broke in 0.36.

[jonas054]

Here's what I think. The --format and --out options are closely tied together, so it's better if we can support @agross's way of defining the options the way it worked in v0.35.1. This should also be documented in the README.

We need to revert the change of this line.

[alexdowad]

Sure, that's cool.

[agross]

Thank you!