Class: RuboCop::Cop::Appdev::PreferWhereOverFind

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Defined in:
lib/rubocop/cop/appdev/prefer_where_over_find.rb

Overview

Forbids ‘Model.find(id)`, `Model.find_by(…)`, and `Model.find_by!(…)` in authored classroom code. The taught pattern is `Model.where({ :col => val }).first` / `.first!`, which makes the query object and indexed access explicit.

Autocorrectable. Behavior is preserved across the rewrite because ‘find` and `.first!` both raise `ActiveRecord::RecordNotFound`, and `find_by` and `.first` both return `nil` on miss.

Examples:

# bad
Movie.find(id)
Movie.find_by(:title => "x")
Movie.find_by!(:title => "x")

# good
Movie.where({ :id => id }).first!
Movie.where({ :title => "x" }).first
Movie.where({ :title => "x" }).first!

Constant Summary collapse

MSG_FIND = 
"Use `.where({ :id => ... }).first!` instead of `.find(...)`."
MSG_FIND_BY = 
"Use `.where(...).first` instead of `.find_by(...)`."
MSG_FIND_BY_BANG = 
"Use `.where(...).first!` instead of `.find_by!(...)`."
RESTRICT_ON_SEND = 
[:find, :find_by, :find_by!].freeze

Instance Method Summary collapse

Instance Method Details

#on_send(node) ⇒ Object 



32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/rubocop/cop/appdev/prefer_where_over_find.rb', line 32

def on_send(node)
  return unless node.receiver
  return if node.block_node
  return if node.arguments.empty?

  case node.method_name
  when :find
    handle_find(node)
  when :find_by
    handle_find_by(node, bang: false)
  when :find_by!
    handle_find_by(node, bang: true)
  end
end