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

Inherits:
RuboCop::Cop show all
Includes:
RangeHelp
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.%<method>s`.'
TARGET_SELECTORS = 
%i[first take].freeze

Instance Method Summary collapse

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/find_by.rb', line 37

def autocorrect(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 node.method?(:first)

  where_loc = node.receiver.loc.selector
  first_loc = range_between(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 Also known as: on_csend 



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# File 'lib/rubocop/cop/rails/find_by.rb', line 26

def on_send(node)
  return unless where_first?(node)

  range = range_between(node.receiver.loc.selector.begin_pos,
                        node.loc.selector.end_pos)

  add_offense(node, location: range,
                    message: format(MSG, method: node.method_name))
end