Class: RuboCop::Cop::Style::IfUnlessModifier

Inherits:
Cop
  • Object
show all
Includes:
RuboCop::Cop::StatementModifier
Defined in:
lib/rubocop/cop/style/if_unless_modifier.rb

Overview

Checks for ‘if` and `unless` statements that would fit on one line if written as modifier `if`/`unless`. The cop also checks for modifier `if`/`unless` lines that exceed the maximum line length.

The maximum line length is configured in the ‘Metrics/LineLength` cop. The tab size is configured in the `IndentationWidth` of the `Layout/Tab` cop.

Examples:

# bad
if condition
  do_stuff(bar)
end

unless qux.empty?
  Foo.do_something
end

do_something_in_a_method_with_a_long_name(arg) if long_condition

# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?

if long_condition
  do_something_in_a_method_with_a_long_name(arg)
end

Constant Summary collapse

MSG_USE_MODIFIER = 
'Favor modifier `%<keyword>s` usage when having a ' \
'single-line body. Another good alternative is ' \
'the usage of control flow `&&`/`||`.'
MSG_USE_NORMAL = 
'Modifier form of `%<keyword>s` makes the line too long.'
ASSIGNMENT_TYPES = 
%i[lvasgn casgn cvasgn
gvasgn ivasgn masgn].freeze

Constants included from Util

Util::LITERAL_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, autocorrect_incompatible_with, badge, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, #correct, department, #disable_uncorrectable, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, #parse, qualified_cop_name, #reason_to_not_correct, #relevant_file?, #target_rails_version, #target_ruby_version

Methods included from AST::Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #correctable?, #disable_offense, #disable_uncorrectable?, #support_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

begins_its_line?, comment_line?, double_quotes_required?, escape_string, first_part_of_call_chain, interpret_string_escapes, line_range, needs_escaping?, on_node, parentheses?, same_line?, to_string_literal, to_supported_styles, tokens, trim_string_interporation_escape_character

Methods included from PathUtil

absolute?, chdir, hidden_dir?, hidden_file_in_not_hidden_dir?, match_path?, pwd, relative_path, reset_pwd, smart_path

Constructor Details

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

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 58

def autocorrect(node)
  replacement = if node.modifier_form?
                  to_normal_form(node)
                else
                  to_modifier_form(node)
                end
  ->(corrector) { corrector.replace(node.source_range, replacement) }
end

#on_if(node) ⇒ Object 



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

def on_if(node)
  msg = if eligible_node?(node)
          MSG_USE_MODIFIER unless named_capture_in_condition?(node)
        elsif node.modifier_form? && too_long_single_line?(node)
          MSG_USE_NORMAL
        end
  return unless msg

  add_offense(node,
              location: :keyword,
              message: format(msg, keyword: node.keyword))
end