class RuboCop::Cop::Style::Next

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

@example EnforcedStyle: skip_modifier_ifs (default)

# 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

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

@example EnforcedStyle: always

# With `always` all conditions at the end of an iteration needs to be
# replaced by next - with `skip_modifier_ifs` the modifier if like
# this one are ignored: `[1, 2].each { |a| puts a if a == 1 }`

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

# 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 Class Methods

autocorrect_incompatible_with() click to toggle source
# File lib/rubocop/cop/style/next.rb, line 58
def self.autocorrect_incompatible_with
  [Style::SafeNavigation]
end

Public Instance Methods

on_block(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 68
def on_block(node)
  return unless node.send_node.send_type? && node.send_node.enumerator_method?

  check(node)
end
Also aliased as: on_numblock
on_for(node)
Alias for: on_while
on_new_investigation() click to toggle source
# File lib/rubocop/cop/style/next.rb, line 62
def on_new_investigation
  # 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_numblock(node)
Alias for: on_block
on_until(node)
Alias for: on_while
on_while(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 76
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 213
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 112
def allowed_modifier_if?(node)
  if node.modifier_form?
    style == :skip_modifier_ifs
  else
    !min_body_length?(node)
  end
end
autocorrect_block(corrector, node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 155
def autocorrect_block(corrector, node)
  next_code = "next #{node.inverse_keyword} #{node.condition.source}"

  corrector.insert_before(node, next_code)

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

  lines = reindentable_lines(node)

  return if lines.empty?

  reindent(lines, node.condition, corrector)
end
autocorrect_modifier(corrector, node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 145
def autocorrect_modifier(corrector, node)
  body = node.if_branch || node.else_branch

  replacement =
    "next #{node.inverse_keyword} #{node.condition.source}\n" \
    "#{' ' * node.source_range.column}#{body.source}"

  corrector.replace(node, replacement)
end
check(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 84
def check(node)
  return unless node.body && ends_with_condition?(node.body)

  offending_node = offense_node(node.body)

  add_offense(offense_location(offending_node)) do |corrector|
    if offending_node.modifier_form?
      autocorrect_modifier(corrector, offending_node)
    else
      autocorrect_block(corrector, offending_node)
    end
  end
end
cond_range(node, cond) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 170
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 189
def end_followed_by_whitespace_only?(source_buffer, end_pos)
  /\A\s*$/.match?(source_buffer.source[end_pos..])
end
end_range(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 180
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 98
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 128
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 217
def heredoc_lines(node)
  node.each_node(:dstr)
      .select(&:heredoc?)
      .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 120
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 124
def if_without_else?(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 140
def offense_location(offense_node)
  offense_begin_pos = offense_node.source_range.begin
  offense_begin_pos.join(offense_node.condition.source_range)
end
offense_node(body) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 134
def offense_node(body)
  *_, condition = *body

  condition&.if_type? ? condition : body
end
reindent(lines, node, corrector) click to toggle source

Adjust indentation of ‘lines` to match `node`

# File lib/rubocop/cop/style/next.rb, line 204
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 { |lineno| reindent_line(corrector, lineno, delta, buffer) }
end
reindent_line(corrector, lineno, delta, buffer) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 224
def reindent_line(corrector, lineno, delta, buffer)
  adjustment = delta + @reindented_lines[lineno]
  @reindented_lines[lineno] = adjustment

  corrector.remove_leading(buffer.line_range(lineno), adjustment) if adjustment.positive?
end
reindentable_lines(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 193
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| /\A\s*\z/.match?(buffer.source_line(lineno)) }
end
simple_if_without_break?(node) click to toggle source
# File lib/rubocop/cop/style/next.rb, line 104
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