Class: RuboCop::Cop::Rails::FindBy

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

Overview

This cop is used to identify usages of ‘where.first` and change them to use `find_by` instead.

Examples:

# bad
User.where(name: 'Bruce').first
User.where(name: 'Bruce').take

# good
User.find_by(name: 'Bruce')

Constant Summary collapse

MSG = 
'Use `find_by` instead of `where.%s`.'.freeze
TARGET_SELECTORS = 
[:first, :take].freeze

Constants included from Util

Util::ASGN_NODES, Util::BYTE_ORDER_MARK, Util::EQUALS_ASGN_NODES, Util::LITERAL_REGEX, Util::OPERATOR_METHODS, Util::SHORTHAND_ASGN_NODES, Util::STRING_ESCAPES, Util::STRING_ESCAPE_REGEX

Instance Attribute Summary

Attributes inherited from Cop

#config, #corrections, #offenses, #processed_source

Instance Method Summary collapse

Methods inherited from Cop

#add_offense, all, #config_to_allow_offenses, #config_to_allow_offenses=, #cop_config, cop_name, #cop_name, cop_type, #correct, #debug?, #details, #display_cop_names?, #display_style_guide?, #excluded_file?, #extra_details?, inherited, #initialize, #join_force?, lint?, match?, #message, non_rails, #parse, qualified_cop_name, #reference_url, #relevant_file?, #style_guide_url, #target_ruby_version

Methods included from Sexp

#s

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search_body

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?, block_length, comment_line?, directions, double_quotes_acceptable?, double_quotes_required?, effective_column, ends_its_line?, first_part_of_call_chain, interpret_string_escapes, line_range, move_pos, numeric_range_size, on_node, operator?, parentheses?, range_with_surrounding_comma, range_with_surrounding_space, source_range, strip_quotes, to_string_literal, to_symbol_literal, within_node?

Methods included from PathUtil

absolute?, hidden?, issue_deprecation_warning, match_path?, relative_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/find_by.rb', line 36

def autocorrect(node)
  receiver, second_method = where_first(node)
  # Don't autocorrect where(...).first, because it can return different
  # results from find_by. (They order records differently, so the
  # 'first' record can be different.)
  return if second_method == :first

  where_loc = receiver.loc.selector
  first_loc = Parser::Source::Range.new(
    node.source_range.source_buffer,
    node.loc.dot.begin_pos,
    node.loc.selector.end_pos
  )

  lambda do |corrector|
    corrector.replace(where_loc, 'find_by')
    corrector.replace(first_loc, '')
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/find_by.rb', line 25

def on_send(node)
  return unless (recv_and_method = where_first(node))
  receiver, second_method = *recv_and_method

  range = Parser::Source::Range.new(node.source_range.source_buffer,
                                    receiver.loc.selector.begin_pos,
                                    node.loc.selector.end_pos)

  add_offense(node, range, format(MSG, second_method))
end