Gemfile

require 'json'
require 'net/http'

source 'https://rubygems.org'


begin
  versions_url = 'https://pages.github.com/versions.json'
  versions     = JSON.parse(Net::HTTP.get(URI(versions_url)))

  # Ensure matching of the local Ruby and gem versions with the production version of GitHub Pages.
  # Maintenance mode: ignore these checks so that non-tech users don't get blocked by a potential change in Ruby versions that they can't fix and that most likely has no impact. These checks are not needed since we build in CI and deploy to GitHub Pages only as a directory of assets.
  # ruby versions['ruby']  # if you go back to actively developing this website, you should uncomment this line
  # gem 'github-pages', versions['github-pages'], group: :jekyll_plugins  # if you go back to actively developing this website, you should uncomment this line
  gem 'github-pages', '~> 212', group: :jekyll_plugins  # if you go back to actively developing this website, you should remove this line

# If the GitHub Pages versions endpoint is unreacheable, assume offline development.
rescue SocketError => socket_error
  # If in CI, this means we can't validate version match, and there is no reason to be offline. Abort.
  raise socket_error if ENV['CI']

  puts "Couldn't reach #{versions_url}, assuming you're offline."

  # Use whichever version is already installed without checking production version match.
  gem 'github-pages'

# Provide a fallback scenario if for any other reason the production versions check fails.
rescue => standard_error
  # If in CI, this means we can't validate version match. Abort.
  # Maintenance mode: ignore this check in CI so that non-tech users don't get blocked by a potential change in gem versions that they can't fix.
  # raise standard_error if ENV['CI']

  puts <<-MESSAGE
    Something went wrong trying to parse production versions: #{standard_error.class.name}
    ---
    #{standard_error.message}
    ---
  MESSAGE

  # Use whichever version is already installed without checking production version match.
  gem 'github-pages'
end

group :jekyll_plugins do
  gem 'jekyll-environment-variables'
 end

group :test do
  gem 'html-proofer'
end