Support .ruby-version

[scottohara]

Many ruby projects include a .ruby-version file in the root directory, containing the version of Ruby needed.

Tools such as rvm, rbenv and chruby all recognise and use this file.

This is not unlike the .nvmrc file often used in Node projects, and the setup-node action has a discussion on potentially using the contents of that file as the node version if no with: argument is specified. (actions/setup-node#32)

I would suggest that setup-ruby might consider a similar approach, where if no explicit ruby version is given, look for a .ruby-version file and use the version contained within.

[tisba]

I was wondering if there is a workaround available, like

- name: Set up Ruby
  uses: actions/setup-ruby@v1
  with:
    ruby-version: "{{ cat('.ruby-version') }}"

However I was not able to figure out how to do that yet :(

[sobstel]

I found a workaround in actions/setup-node repo.

- run: echo "::set-output name=RUBY_VERSION::$(cat .ruby-version)"
  id: rbenv

- uses: actions/setup-ruby@v1
  with:
   ruby-version: "${{ steps.rbenv.outputs.RUBY_VERSION }}"

[bryanmacfarlane]

happy to see the workaround ☝️ - leaving as an enhancement for consideration

[vvo]

@bryanmacfarlane To be honest, and without any anger or nothing, I want to point out that supporting .ruby-version should not be seen as an "enhancement" but as a requirement for the ruby community. When any company starts a Ruby project they will first choose between rvm or rbenv, most of them. And the next step will be to create a .ruby-version file to easily create a reproducible environment for devs and continuous integration, which is supported by both rbenv and rvm.

Thus I think we should consider supporting the .ruby-version really as a requirement to consider "setup-ruby" good enough for any Ruby project. Right now a lot of people are just not using it and instead using https://github.com/eregon/use-ruby-action or https://github.com/masa-iwasaki/setup-rbenv.

I think it's fine and great that people are creating actions on the marketplace but for some very popular actions, the ones from GitHub should really cover most use cases otherwise we'll endup with a marketplace like the npm registry where you spend half a day trying to find the "right" ruby action that works well..

Thanks for consideration!

PS: Maybe @eregon, creator of use-ruby-action you have some thoughts about this too? Thanks!

[eregon]

I implemented it in use-ruby-action (issue: ruby/setup-ruby#4).
It's really trivial.

I think longer term we'll want most (all maybe) features of use-ruby-action in this repo: #44