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

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
AllowedPattern, LineLengthHelp, RangeHelp, 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 ‘Layout/LineLength` cop. The tab size is configured in the `IndentationWidth` of the `Layout/IndentationStyle` cop.

NOTE: It is allowed when ‘defined?` argument has an undefined value, because using the modifier form causes the following incompatibility:

source,ruby

unless defined?(undefined_foo)

undefined_foo = 'default_value'

end undefined_foo # => ‘default_value’

undefined_bar = ‘default_value’ unless defined?(undefined_bar) undefined_bar # => nil

Examples:

# bad
if condition
  do_stuff(bar)
end

unless qux.empty?
  Foo.do_something
end

do_something_with_a_long_name(arg) if long_condition_that_prevents_code_fit_on_single_line

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

if long_condition_that_prevents_code_fit_on_single_line
  do_something_with_a_long_name(arg)
end

if short_condition # a long comment that makes it too long if it were just a single line
  do_something
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.'

Constants inherited from Base

Base::RESTRICT_ON_SEND

Instance Attribute Summary

Attributes inherited from Base

#config, #processed_source

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Methods inherited from Base

#active_support_extensions_enabled?, #add_global_offense, #add_offense, badge, #begin_investigation, #callbacks_needed, callbacks_needed, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, #cop_name, cop_name, department, documentation_url, exclude_from_registry, #excluded_file?, #external_dependency_checksum, inherited, #initialize, joining_forces, lint?, match?, #message, #offenses, #on_investigation_end, #on_new_investigation, #on_other_file, #parse, #ready, #relevant_file?, support_autocorrect?, support_multiple_source?, #target_rails_version, #target_ruby_version

Methods included from ExcludeLimit

#exclude_limit

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #autocorrect_with_disable_uncorrectable?, #correctable?, #disable_uncorrectable?, #safe_autocorrect?

Methods included from IgnoredNode

#ignore_node, #ignored_node?, #part_of_ignored_node?

Methods included from Util

silence_warnings

Constructor Details

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

Class Method Details

.autocorrect_incompatible_with ⇒ Object 



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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 63

def self.autocorrect_incompatible_with
  [Style::SoleNestedConditional]
end

Instance Method Details

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/if_unless_modifier.rb', line 67

def on_if(node)
  return if defined_nodes(node).any? { |n| defined_argument_is_undefined?(node, n) }

  msg = if single_line_as_modifier?(node) && !named_capture_in_condition?(node)
          MSG_USE_MODIFIER
        elsif too_long_due_to_modifier?(node)
          MSG_USE_NORMAL
        end
  return unless msg

  add_offense(node.loc.keyword, message: format(msg, keyword: node.keyword)) do |corrector|
    autocorrect(corrector, node)
  end
end