align_parameters.rb

# frozen_string_literal: true

module RuboCop
  module Cop
    module Layout
      # Here we check if the parameters on a multi-line method call or
      # definition are aligned.
      #
      # @example EnforcedStyle: with_first_parameter (default)
      #   # good
      #
      #   foo :bar,
      #       :baz
      #
      #   # bad
      #
      #   foo :bar,
      #     :baz
      #
      # @example EnforcedStyle: with_fixed_indentation
      #   # good
      #
      #   foo :bar,
      #     :baz
      #
      #   # bad
      #
      #   foo :bar,
      #       :baz
      class AlignParameters < Cop
        include Alignment

        ALIGN_PARAMS_MSG = 'Align the parameters of a method %<type>s if ' \
          'they span more than one line.'.freeze

        FIXED_INDENT_MSG = 'Use one level of indentation for parameters ' \
          'following the first line of a multi-line method %<type>s.'.freeze

        def on_send(node)
          return if node.arguments.size < 2 ||
                    node.send_type? && node.method?(:[]=)

          check_alignment(node.arguments, base_column(node, node.arguments))
        end
        alias on_csend on_send
        alias on_def  on_send
        alias on_defs on_send

        def autocorrect(node)
          AlignmentCorrector.correct(processed_source, node, column_delta)
        end

        private

        def message(node)
          type = if node && (node.parent.send_type? || node.parent.csend_type?)
                   'call'
                 else
                   'definition'
                 end
          msg = fixed_indentation? ? FIXED_INDENT_MSG : ALIGN_PARAMS_MSG

          format(msg, type: type)
        end

        def fixed_indentation?
          cop_config['EnforcedStyle'] == 'with_fixed_indentation'
        end

        def base_column(node, args)
          if fixed_indentation?
            lineno = target_method_lineno(node)
            line = node.source_range.source_buffer.source_line(lineno)
            indentation_of_line = /\S.*/.match(line).begin(0)
            indentation_of_line + configured_indentation_width
          else
            display_column(args.first.source_range)
          end
        end

        def target_method_lineno(node)
          if node.def_type? || node.defs_type?
            node.loc.keyword.line
          elsif node.loc.selector
            node.loc.selector.line
          else
            # l.(1) has no selector, so we use the opening parenthesis instead
            node.loc.begin.line
          end
        end
      end
    end
  end
end