Class: RuboCop::Cop::Rails::Blank

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/rails/blank.rb

Overview

This cop checks for code that can be written with simpler conditionals using `Object#blank?` defined by Active Support.

Examples:

NilOrEmpty: true (default)

# Converts usages of `nil? || empty?` to `blank?`

# bad
foo.nil? || foo.empty?
foo == nil || foo.empty?

# good
foo.blank?

NotPresent: true (default)

# Converts usages of `!present?` to `blank?`

# bad
!foo.present?

# good
foo.blank?

UnlessPresent: true (default)

# Converts usages of `unless present?` to `if blank?`

# bad
something unless foo.present?

# good
something if foo.blank?

# bad
unless foo.present?
  something
end

# good
if foo.blank?
  something
end

# good
def blank?
  !present?
end

Constant Summary collapse

MSG_NIL_OR_EMPTY =
'Use `%<prefer>s` instead of `%<current>s`.'.freeze
MSG_NOT_PRESENT =
'Use `%<prefer>s` instead of `%<current>s`.'.freeze
MSG_UNLESS_PRESENT =
'Use `if %<prefer>s` instead of ' \
'`%<current>s`.'.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, #duplicate_location?, #excluded_file?, #find_location, #highlights, inherited, #initialize, #join_force?, lint?, match?, #message, #messages, non_rails, #parse, qualified_cop_name, #relevant_file?, #target_rails_version, #target_ruby_version

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 AST::Sexp

#s

Methods included from AutocorrectLogic

#autocorrect?, #autocorrect_enabled?, #autocorrect_requested?, #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

Methods included from PathUtil

absolute?, 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/rails/blank.rb', line 126

def autocorrect(node)
  lambda do |corrector|
    method_call, variable1 = unless_present?(node)

    if method_call
      corrector.replace(node.loc.keyword, 'if')
      range = method_call.loc.expression
    else
      variable1, _variable2 = nil_or_empty?(node) || not_present?(node)
      range = node.loc.expression
    end

    corrector.replace(range, replacement(variable1))
  end
end

#on_if(node) ⇒ Object



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# File 'lib/rubocop/cop/rails/blank.rb', line 111

def on_if(node)
  return unless cop_config['UnlessPresent']
  return unless node.unless?

  unless_present?(node) do |method_call, receiver|
    range = unless_condition(node, method_call)

    add_offense(node,
                location: range,
                message: format(MSG_UNLESS_PRESENT,
                                prefer: replacement(receiver),
                                current: range.source))
  end
end

#on_or(node) ⇒ Object



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# File 'lib/rubocop/cop/rails/blank.rb', line 98

def on_or(node)
  return unless cop_config['NilOrEmpty']

  nil_or_empty?(node) do |var1, var2|
    return unless var1 == var2

    add_offense(node,
                message: format(MSG_NIL_OR_EMPTY,
                                prefer: replacement(var1),
                                current: node.source))
  end
end

#on_send(node) ⇒ Object



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# File 'lib/rubocop/cop/rails/blank.rb', line 84

def on_send(node)
  return unless cop_config['NotPresent']

  not_present?(node) do |receiver|
    # accepts !present? if its in the body of a `blank?` method
    next if defining_blank?(node.parent)

    add_offense(node,
                message: format(MSG_NOT_PRESENT,
                                prefer: replacement(receiver),
                                current: node.source))
  end
end