class RuboCop::Cop::Style::EmptyMethod

Checks for the formatting of empty method definitions. By default it enforces empty method definitions to go on a single line (compact style), but it can be configured to enforce the `end` to go on its own line (expanded style).

NOTE: A method definition is not considered empty if it contains comments.

NOTE: Autocorrection will not be applied for the `compact` style if the resulting code is longer than the `Max` configuration for `Layout/LineLength`, but an offense will still be registered.

@example EnforcedStyle: compact (default)

# bad
def foo(bar)
end

def self.foo(bar)
end

# good
def foo(bar); end

def foo(bar)
  # baz
end

def self.foo(bar); end

@example EnforcedStyle: expanded

# bad
def foo(bar); end

def self.foo(bar); end

# good
def foo(bar)
end

def self.foo(bar)
end

Constants

MSG_COMPACT
MSG_EXPANDED

Public Instance Methods

on_def(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 54
def on_def(node)
  return if node.body || processed_source.contains_comment?(node.source_range)
  return if correct_style?(node)

  add_offense(node) do |corrector|
    correction = corrected(node)
    next if compact_style? && max_line_length && correction.size > max_line_length

    corrector.replace(node, correction)
  end
end
Also aliased as: on_defs
on_defs(node)
Alias for: on_def

Private Instance Methods

compact?(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 95
def compact?(node)
  node.single_line?
end
compact_style?() click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 103
def compact_style?
  style == :compact
end
correct_style?(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 73
def correct_style?(node)
  (compact_style? && compact?(node)) || (expanded_style? && expanded?(node))
end
corrected(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 77
def corrected(node)
  scope = node.receiver ? "#{node.receiver.source}." : ''
  arguments = if node.arguments?
                args = node.arguments.map(&:source).join(', ')

                parentheses?(node.arguments) ? "(#{args})" : " #{args}"
              end
  signature = [scope, node.method_name, arguments].join

  ["def #{signature}", 'end'].join(joint(node))
end
expanded?(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 99
def expanded?(node)
  node.multiline?
end
expanded_style?() click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 107
def expanded_style?
  style == :expanded
end
joint(node) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 89
def joint(node)
  indent = ' ' * node.loc.column

  compact_style? ? '; ' : "\n#{indent}"
end
max_line_length() click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 111
def max_line_length
  return unless config.for_cop('Layout/LineLength')['Enabled']

  config.for_cop('Layout/LineLength')['Max']
end
message(_range) click to toggle source
# File lib/rubocop/cop/style/empty_method.rb, line 69
def message(_range)
  compact_style? ? MSG_COMPACT : MSG_EXPANDED
end