class RuboCop::Cop::Style::Next

Use `next` to skip iteration instead of a condition at the end.

@example

# bad
[1, 2].each do |a|
  if a == 1
    puts a
  end
end

# good
[1, 2].each do |a|
  next unless a == 1
  puts a
end

Constants

EXIT_TYPES
MSG

Public Instance Methods

investigate(_processed_source) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 28
def investigate(_processed_source)
  # When correcting nested offenses, we need to keep track of how much
  # we have adjusted the indentation of each line
  @reindented_lines = Hash.new(0)
end
on_block(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 34
def on_block(node)
  return unless node.send_node.send_type? &&
                node.send_node.enumerator_method?

  check(node)
end
on_for(node)
Alias for: on_while
on_until(node)
Alias for: on_while
on_while(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 41
def on_while(node)
  check(node)
end
Also aliased as: on_until, on_for

Private Instance Methods

actual_indent(lines, buffer) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 190
def actual_indent(lines, buffer)
  lines.map { |lineno| buffer.source_line(lineno) =~ /\S/ }.min
end
allowed_modifier_if?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 72
def allowed_modifier_if?(node)
  if node.modifier_form?
    style == :skip_modifier_ifs
  else
    !min_body_length?(node)
  end
end
autocorrect(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 105
def autocorrect(node)
  lambda do |corrector|
    if node.modifier_form?
      autocorrect_modifier(corrector, node)
    else
      autocorrect_block(corrector, node)
    end
  end
end
autocorrect_block(corrector, node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 125
def autocorrect_block(corrector, node)
  cond, if_body, = *node

  next_code = "next #{opposite_kw(if_body)} #{cond.source}"
  corrector.insert_before(node.source_range, next_code)

  corrector.remove(cond_range(node, cond))
  corrector.remove(end_range(node))

  lines = reindentable_lines(node)
  return if lines.empty?

  reindent(lines, cond, corrector)
end
autocorrect_modifier(corrector, node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 115
def autocorrect_modifier(corrector, node)
  cond, if_body, else_body = *node
  body = if_body || else_body

  replacement = "next #{opposite_kw(if_body)} #{cond.source}\n" \
                "#{' ' * node.source_range.column}#{body.source}"

  corrector.replace(node.source_range, replacement)
end
check(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 49
def check(node)
  return unless node.body && ends_with_condition?(node.body)

  offending_node = offense_node(node.body)

  add_offense(offending_node,
              location: offense_location(offending_node))
end
cond_range(node, cond) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 144
def cond_range(node, cond)
  end_pos = if node.loc.begin
              node.loc.begin.end_pos # after "then"
            else
              cond.source_range.end_pos
            end

  range_between(node.source_range.begin_pos, end_pos)
end
end_followed_by_whitespace_only?(source_buffer, end_pos) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 164
def end_followed_by_whitespace_only?(source_buffer, end_pos)
  source_buffer.source[end_pos..-1] =~ /\A\s*$/
end
end_range(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 154
def end_range(node)
  source_buffer = node.source_range.source_buffer
  end_pos = node.loc.end.end_pos
  begin_pos = node.loc.end.begin_pos - node.loc.end.column
  begin_pos -= 1 if end_followed_by_whitespace_only?(source_buffer,
                                                     end_pos)

  range_between(begin_pos, end_pos)
end
ends_with_condition?(body) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 58
def ends_with_condition?(body)
  return true if simple_if_without_break?(body)

  body.begin_type? && simple_if_without_break?(body.children.last)
end
exit_body_type?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 88
def exit_body_type?(node)
  return false unless node.if_branch

  EXIT_TYPES.include?(node.if_branch.type)
end
heredoc_lines(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 194
def heredoc_lines(node)
  node.each_node(:dstr)
      .select { |n| n.loc.respond_to?(:heredoc_body) }
      .map { |n| n.loc.heredoc_body }
      .flat_map { |b| (b.line...b.last_line).to_a }
end
if_else_children?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 80
def if_else_children?(node)
  node.each_child_node(:if).any?(&:else?)
end
if_without_else?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 84
def if_without_else?(node)
  node && node.if_type? && !node.ternary? && !node.else?
end
offense_location(offense_node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 99
def offense_location(offense_node)
  condition_expression, = *offense_node
  offense_begin_pos = offense_node.source_range.begin
  offense_begin_pos.join(condition_expression.source_range)
end
offense_node(body) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 94
def offense_node(body)
  *_, condition = *body
  condition && condition.if_type? ? condition : body
end
opposite_kw(if_body) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 140
def opposite_kw(if_body)
  if_body.nil? ? 'if' : 'unless'
end
reindent(lines, node, corrector) click to toggle source

Adjust indentation of `lines` to match `node`

# File lib/rubocop/cop/style/next.rb, line 179
def reindent(lines, node, corrector)
  range  = node.source_range
  buffer = range.source_buffer

  target_indent = range.source_line =~ /\S/
  delta = actual_indent(lines, buffer) - target_indent
  lines.each do |lineno|
    reindent_line(corrector, lineno, delta, buffer)
  end
end
reindent_line(corrector, lineno, delta, buffer) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 201
def reindent_line(corrector, lineno, delta, buffer)
  adjustment = delta + @reindented_lines[lineno]
  @reindented_lines[lineno] = adjustment

  if adjustment > 0
    corrector.remove_leading(buffer.line_range(lineno), adjustment)
  elsif adjustment < 0
    corrector.insert_before(buffer.line_range(lineno),
                            ' ' * -adjustment)
  end
end
reindentable_lines(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 168
def reindentable_lines(node)
  buffer = node.source_range.source_buffer

  # end_range starts with the final newline of the if body
  lines = (node.source_range.line + 1)...node.loc.end.line
  lines = lines.to_a - heredoc_lines(node)
  # Skip blank lines
  lines.reject { |lineno| buffer.source_line(lineno) =~ /\A\s*\z/ }
end
simple_if_without_break?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 64
def simple_if_without_break?(node)
  return false unless if_without_else?(node)
  return false if if_else_children?(node)
  return false if allowed_modifier_if?(node)

  !exit_body_type?(node)
end