module T::NonForcingConstants

def self.non_forcing_is_a?(val, klass, package: nil)
  method_name = "T::NonForcingConstants.non_forcing_is_a?"
  if klass.empty?
    raise ArgumentError.new("The string given to `#{method_name}` must not be empty")
  end
  # We don't treat packages differently at runtime, but the static
  # type-checker still needs to have the package and constant
  # separated out. This just re-assembles the string as needed
  if !package.nil?
    klass = "::#{package}::#{klass}"
  end
  current_klass = T.let(nil, T.nilable(Module))
  current_prefix = T.let(nil, T.nilable(String))
  parts = klass.split('::')
  parts.each do |part|
    if current_klass.nil?
      # First iteration
      if part != "" && package.nil?
        # if we've supplied a package, we're probably running in
        # package mode, which means absolute references are
        # meaningless
        raise ArgumentError.new("The string given to `#{method_name}` must be an absolute constant reference that starts with `::`")
      end
      current_klass = Object
      current_prefix = ''
      # if this had a :: prefix, then there's no more loading to
      # do---skip to the next one
      next if part == ""
    end
    if current_klass.autoload?(part)
      # There's an autoload registered for that constant, which means it's not
      # yet loaded. `value` can't be an instance of something not yet loaded.
      return false
    end
    # Sorbet guarantees that the string is an absolutely resolved name.
    search_inheritance_chain = false
    if !current_klass.const_defined?(part, search_inheritance_chain)
      return false
    end
    current_klass = current_klass.const_get(part)
    current_prefix = "#{current_prefix}::#{part}"
    if !Module.===(current_klass)
      raise ArgumentError.new("#{current_prefix} is not a class or module")
    end
  end
  current_klass.===(val)
end