committee_reloader.rb

# @example
#   Rails.configuration.middleware.use(
#     CommitteeReloader,
#     "path/to/schema",
#     [
#       Committee::Middleware::RequestValidation,
#       schema_path: "path/to/schema"
#     ]
#   )
class CommitteeReloader
  def initialize(app, files, *middlewares)
    @original_app = proc { |env| app.call env }
    @middlewares = middlewares.reverse
    @files = Array(files)
  end

  def call(env)
    check
    @app.call(env)
  end

  def check
    current = @files.map { |file| File.mtime(file) }.max
    return if @latest == current

    @latest = current
    build
  end

  def build
    @app = @middlewares.inject(@original_app) do |result, (klass, args)|
      klass.new(result, args)
    end
  end
end