Class: RuboCop::Cop::Style::MultilineBlockLayout

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/style/multiline_block_layout.rb

Overview

This cop checks whether the multiline do end blocks have a newline after the start of the block. Additionally, it checks whether the block arguments, if any, are on the same line as the start of the block.

Examples:

# bad
blah do |i| foo(i)
  bar(i)
end

# bad
blah do
  |i| foo(i)
  bar(i)
end

# good
blah do |i|
  foo(i)
  bar(i)
end

# bad
blah { |i| foo(i)
  bar(i)
}

# good
blah { |i|
  foo(i)
  bar(i)
}

Constant Summary collapse

MSG = 
'Block body expression is on the same line as ' \
'the block start.'.freeze
ARG_MSG = 
'Block argument expression is not on the same line as the ' \
'block start.'.freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES, Util::STRING_ESCAPES, Util::STRING_ESCAPE_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search_body

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, numeric_range_size, on_node, operator?, parentheses?, parenthesized_call?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, ternary_op?, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, hidden?, issue_deprecation_warning, match_path?, relative_path

Constructor Details

This class inherits a constructor from RuboCop::Cop::Cop

Instance Method Details

#add_offense_for_expression(node, expr, msg) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 67

def add_offense_for_expression(node, expr, msg)
  expression = expr.source_range
  range = Parser::Source::Range.new(expression.source_buffer,
                                    expression.begin_pos,
                                    expression.end_pos)

  add_offense(node, range, msg)
end

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 76

def autocorrect(node)
  lambda do |corrector|
    _method, args, block_body = *node
    unless args.children.empty? || args.loc.last_line == node.loc.line
      autocorrect_arguments(corrector, node, args)
      expr_before_body = args.source_range.end
    end

    return unless block_body

    expr_before_body ||= node.loc.begin
    if expr_before_body.line == block_body.loc.line
      autocorrect_body(corrector, node, block_body)
    end
  end
end

#autocorrect_arguments(corrector, node, args) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 93

def autocorrect_arguments(corrector, node, args)
  end_pos =
    range_with_surrounding_space(args.source_range, :right, false)
    .end_pos
  range = Parser::Source::Range.new(args.source_range.source_buffer,
                                    node.loc.begin.end.begin_pos,
                                    end_pos)
  corrector.replace(range, " |#{block_arg_string(args)}|")
end

#autocorrect_body(corrector, node, block_body) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 103

def autocorrect_body(corrector, node, block_body)
  first_node = if block_body.type == :begin
                 block_body.children.first
               else
                 block_body
               end

  block_start_col = node.source_range.column

  corrector.insert_before(first_node.source_range,
                          "\n  #{' ' * block_start_col}")
end

#block_arg_string(args) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 116

def block_arg_string(args)
  args.children.map do |arg|
    if arg.mlhs_type?
      "(#{block_arg_string(arg)})"
    else
      arg.source
    end
  end.join(', ')
end

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/multiline_block_layout.rb', line 45

def on_block(node)
  end_loc = node.loc.end
  do_loc = node.loc.begin # Actually it's either do or {.
  return if do_loc.line == end_loc.line # One-liner, no newline needed.

  # A block node has three children: the block start,
  # the arguments, and the expression. We care if the block start
  # with arguments and the expression start on the same line.
  _block_start, args, last_expression = node.children

  unless args.children.empty?
    if do_loc.line != args.loc.last_line
      add_offense_for_expression(node, args, ARG_MSG)
    end
  end

  return unless last_expression
  expression_loc = last_expression.loc
  return unless do_loc.line == expression_loc.line
  add_offense_for_expression(node, last_expression, MSG)
end