Support Gemfile source variables

[rarkins]

Describe the proposed change(s).

Support parsing source values in variables like so:

source 'https://nexus.company.net/repository/rubygems-proxy-repos-group/'
private_gem_source = 'https://nexus.company.net/repository/rubygems-secondary-repos-group/'

gem 'activesupport', '>= 7.0.4.3' # CVE-2023-28120
gem 'faraday', '~> 2.7'
gem 'faraday-encoding', '~> 0.0.5'
gem 'rails', '~> 7.0.4'
gem 'redis', '~> 5.0.5'

source private_gem_source do
  gem 'private-kafka', '~> 0.34.1'
  gem 'private-logger', '~> 1.0'
  gem 'private-metrics', '~> 3.6'
end

Describe why we need/want these change(s).

This is a common pattern. Today we support only direct URLs like so:

source 'https://nexus.company.net/repository/rubygems-proxy-repos-group/'

gem 'activesupport', '>= 7.0.4.3' # CVE-2023-28120
gem 'faraday', '~> 2.7'
gem 'faraday-encoding', '~> 0.0.5'
gem 'rails', '~> 7.0.4'
gem 'redis', '~> 5.0.5'

source 'https://nexus.company.net/repository/rubygems-secondary-repos-group/' do
  gem 'private-kafka', '~> 0.34.1'
  gem 'private-logger', '~> 1.0'
  gem 'private-metrics', '~> 3.6'
end

[rarkins]

@Djiit the code would need to be added in https://github.com/renovatebot/renovate/blob/main/lib/modules/manager/bundler/extract.ts

The logic iterates through the Gemfile line by line, so you'd probably want to:

• Initialize an empty set of sources
• For each line, see if it matches the variable assignment pattern, and store the key/value if so
• For any subsequent source definition, see if it matches a key in the source list

[renovate-release]

🎉 This issue has been resolved in version 39.17.0 🎉

The release is available on:

• GitHub release
• npm package (@latest dist-tag)
• 39.17.0

Your semantic-release bot 📦🚀