Class: Twig::Util::CallableArgumentsExtractor

Inherits:
Object
  • Object
show all
Defined in:
lib/twig/util/callable_arguments_extractor.rb

Instance Method Summary collapse

Constructor Details

#initialize(node, twig_callable, environment) ⇒ CallableArgumentsExtractor 



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# File 'lib/twig/util/callable_arguments_extractor.rb', line 9

def initialize(node, twig_callable, environment)
  @node = node
  @twig_callable = twig_callable
  @environment = environment
end

Instance Method Details

#extract_arguments(arguments) ⇒ Object 



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# File 'lib/twig/util/callable_arguments_extractor.rb', line 16

def extract_arguments(arguments)
  # Check argument order first
  found_named = false
  arguments.nodes.each_key do |key|
    if key.is_a?(Integer)
      if found_named
        raise Error::Syntax.new(
          "Positional arguments cannot be used after named arguments for #{@twig_callable.type} " \
          "\"#{@twig_callable.name}\".",
          @node.lineno,
          @node.source_context
        )
      end
    else
      found_named = true
    end
  end

  called_arguments = destination_arguments.keys.to_h { |k| [k, false] }

  spreads, arguments = arguments.nodes.partition do |_, node|
    node.is_a?(Node::Expression::Unary::Spread)
  end.map(&:to_h)

  positional, kwargs = arguments.partition do |key, _node|
    key.is_a?(Integer)
  end.map(&:to_h)

  positional = positional.values
  positional_count = positional.length

  kwargs.transform_keys!(&:to_sym)
  resolved_positional = []
  resolved_kwargs = {}
  rest = false
  keyrest = false

  destination_arguments.each do |name, type|
    if positional.any?
      case type
      when :req, :opt
        resolved_positional << positional.shift
      when :keyreq, :key
        arg = positional.shift

        if arg.is_a?(Node::Expression::Unary::HashSpread)
          keyrest = true
          resolved_positional << arg
        else
          resolved_kwargs[name] = arg
        end
      when :rest
        resolved_positional += positional
        positional = []
        rest = true
        next
      when :keyrest
        arg = positional.shift

        if arg.is_a?(Node::Expression::Unary::HashSpread)
          keyrest = true
          resolved_positional << arg
        else
          raise Error::Syntax.new(
            "Expected a hash spread for argument \"#{name}\" " \
            "for #{@twig_callable.type} \"#{@twig_callable.name}\".",
            @node.lineno,
            @node.source_context
          )
        end

        next
      else
        raise "Unknown argument type: #{name} #{type}"
      end
    elsif kwargs.key?(name) || (found = kwargs.keys.detect { |key| key.to_s.underscore.to_sym == name })
      found = name if found.nil?

      if i[opt req].include?(type)
        resolved_positional << kwargs.delete(found)
      else
        resolved_kwargs[name] = kwargs.delete(found)
      end
    else
      case type
      when :opt, :key, :rest
        next
      when :keyrest
        keyrest = true
        resolved_kwargs.merge!(kwargs)
        kwargs = {}
        next
      else
        # If we have spreads, we just can't know until runtime since we don't know if it's a
        # positional spread or kwarg spread because both use ...
        unless spreads.any? || keyrest
          raise Error::Syntax.new(
            "Value for argument \"#{name}\" is required for #{@twig_callable.type} \"#{@twig_callable.name}\".",
            @node.lineno,
            @node.source_context
          )
        end
      end
    end

    called_arguments[name] = true
  end

  # If any of our remaining kwargs intersect with called_arguments then we have a duplicate key
  duplicated = called_arguments.select { |_k, v| v }.keys & kwargs.keys
  duplicated = duplicated.map(&:to_s)
  duplicated = duplicated[0] if duplicated.one?

  unless duplicated.empty?
    raise Error::Syntax.new(
      "Argument #{duplicated.inspect} is defined twice for #{@twig_callable.type} " \
      "\"#{@twig_callable.name}\".",
      @node.lineno,
      @node.source_context
    )
  end

  unexpected_arguments = []
  unknown_argument = nil

  # If there's no keyrest and any kwargs left, they are extraneous
  if !keyrest && kwargs.any?
    unexpected_arguments += kwargs.keys
    unknown_argument = kwargs.values.first
  end

  # If there's a rest and any positional left, they are extraneous
  if !rest && positional.any?
    unexpected_arguments += [
      *((positional_count - positional.length)...positional_count),
    ]
    unknown_argument = positional.first
  end

  if unexpected_arguments.any?
    unknown_argument ||= @node

    raise Error::Syntax.new(
      "Unknown argument \"#{unexpected_arguments.join(', ')}\" " \
      "for #{@twig_callable.type} \"#{@twig_callable.name}(#{destination_arguments.keys.join(', ')})\".",
      unknown_argument.lineno,
      unknown_argument.source_context
    )
  end

  [resolved_positional + spreads.values, resolved_kwargs]
end