Using faraday and rack-cache to cache API calls

client.rb

# removes "private" bit from Cache-Control headers
PrivateCacheBuster = Struct.new :app do
  def call env
    response = app.call env
    response['cache-control'].sub!('private, ', '') if response['cache-control']
    response
  end
end

# removes nil request headers created by bug
# https://github.com/pengwynn/faraday_middleware/pull/35
NilHeaderExterminator = Struct.new :app do
  def call env
    env[:request_headers].reject! { |name, value| value.nil? }
    app.call env
  end
end

def api_client options = {}
  options = { oauth_token: auth_token,
              faraday_config_block: lambda { |conn|
                conn.use FaradayMiddleware::RackCompatible, Rack::Cache::Context,
                  :metastore      => "file:myappmeta",
                  :entitystore    => "file:myappbody",
                  :ignore_headers => %w[Set-Cookie X-Content-Digest]
                conn.use PrivateCacheBuster
                conn.use NilHeaderExterminator
              }
            }
  Octokit::Client.new options
end