Add required_ruby_version to gemspec

[dkubb]

I see in the travis configuration that rubocop is only tested with ruby 1.9.3 and up. Would you consider adding a s.required_ruby_version = '>= 1.9.3' to the gemspec to make the required version explicit?

[bbatsov]

We do unofficially support 1.9.2 (or at least I thought we did - obviously the dependency to json is problematic there). I've been thinking for a while to drop support for it (as we don't test it on Travis and 2.1 is around the corner). I doubt that many people are using 1.9.2 these days, anyways.

@jonas054 @yujinakayama Thoughts?

[jonas054]

I think we've had this problem with the missing dependency to the json gem for about 6 months. That's an indication that it would be safe to drop 1.9.2 support. I don't have a strong opinon about whether to keep it, but if we do decide to do so we should test 1.9.2 on Travis too.

[sferik]

For what it’s worth, Ruby 1.9.2 just got another 6 month lease on life. The fact that Heroku is spending their time/money to support Ruby 1.9.2 signals that a significant number of their customers are still using it. As such, I’d like to be able to test my projects against Ruby 1.9.2 and while using RuboCop. To do this currently, I need to specify a json dependency. I suppose I could do the following in the Gemfile (but I’d rather not):

gem 'rubocop' if RUBY_VERSION >= "1.9.3"

I agree with @jonas054: Either Ruby 1.9.2 should be officially supported, added to the Travis matrix, and json added as a dependency or Ruby 1.9.2 support should be dropped, in which case you should take @dkubb’s suggestion and specify a required_ruby_version in the gemspec.

Personally, I would prefer to see official Ruby 1.9.2 support, at least for the next 6 months, while Heroku migrates their customers to Ruby 1.9.3 or higher. I’d be willing to help provide support for Ruby 1.9.2 in this project, if you foresee it being a burden on the existing maintainers.

[yujinakayama]

Personally, I would prefer to see official Ruby 1.9.2 support, at least for the next 6 months,

I agree with @sferik.

I just ran RuboCop's specs on 1.9.2-p320 and everything was green (though Parser warned about syntax compatibility). I think we can support 1.9.2 with minimal effort for 6 months and it's worth rather than giving 1.9.2 users errors and suggesting some workaround.

[bbatsov]

@yujinakayama Makes sense. Go ahead and make the necessary changes for official 1.9.2 compatibility.