Class: RuboCop::Cop::Style::InfiniteLoop

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 84

def assigned_before_loop?(var, range)
  b = range.begin_pos
  var.assignments.any? { |a| a.node.source_range.end_pos < b }
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 80

def assigned_inside_loop?(var, range)
  var.assignments.any? { |a| range.contains?(a.node.source_range) }
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 70

def autocorrect(corrector, node)
  if node.while_post_type? || node.until_post_type?
    replace_begin_end_with_modifier(corrector, node)
  elsif node.modifier_form?
    replace_source(corrector, node.source_range, modifier_replacement(node))
  else
    replace_source(corrector, non_modifier_range(node), 'loop do')
  end
end

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

def modifier_replacement(node)
  body = node.body
  if node.single_line?
    "loop { #{body.source} }"
  else
    indentation = body.source_range.source_line[LEADING_SPACE]

    ['loop do', body.source.gsub(/^/, indentation(node)), 'end'].join("\n#{indentation}")
  end
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 114

def non_modifier_range(node)
  start_range = node.loc.keyword.begin
  end_range = if node.do?
                node.loc.begin.end
              else
                node.condition.source_range.end
              end

  start_range.join(end_range)
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 44

def on_until(node)
  while_or_until(node) if node.condition.falsey_literal?
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 49

alias on_until_post on_until

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 40

def on_while(node)
  while_or_until(node) if node.condition.truthy_literal?
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 48

alias on_while_post on_while

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 89

def referenced_after_loop?(var, range)
  e = range.end_pos
  var.references.any? { |r| r.node.source_range.begin_pos > e }
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 94

def replace_begin_end_with_modifier(corrector, node)
  corrector.replace(node.body.loc.begin, 'loop do')
  corrector.remove(node.body.loc.end.end.join(node.source_range.end))
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 99

def replace_source(corrector, range, replacement)
  corrector.replace(range, replacement)
end

# File 'lib/rubocop/cop/style/infinite_loop.rb', line 53

def while_or_until(node)
  range = node.source_range
  # Not every `while true` and `until false` can be turned into a
  # `loop do` without further modification. The reason is that a
  # variable that's introduced inside a while/until loop is in scope
  # outside of that loop too, but a variable that's assigned for the
  # first time inside a block cannot be accessed after the block. In
  # those more complicated cases we don't report an offense.
  return if @variables.any? do |var|
    assigned_inside_loop?(var, range) &&
    !assigned_before_loop?(var, range) &&
    referenced_after_loop?(var, range)
  end

  add_offense(node.loc.keyword) { |corrector| autocorrect(corrector, node) }
end