module Lato::DependencyHelper

def depends_on(gem_name, req: true)
  gem(gem_name) # require the gem
  return(true) unless defined?(Bundler) # If we're in a non-bundler environment, we're no longer able to determine if we'll meet requirements
  gem_version = Gem.loaded_specs[gem_name].version
  gem_requirement = Bundler.load.dependencies.find { |g| g.name == gem_name }&.requirement
  raise LoadError unless gem_requirement
  unless gem_requirement.satisfied_by?(gem_version)
    raise VersionError, "The #{gem_name} gem is installed, but version #{gem_requirement} is required. You have #{gem_version}."
  end
  lib_name = gem_name if req == true
  lib_name = req if req.is_a?(String)
  require(lib_name) if lib_name
  true
rescue ::LoadError
  raise LoadError, "Could not load #{gem_name}. Please ensure that the #{gem_name} gem is installed."
end