Sha256: eaadf34818155825fb412c2e343c02f0a2dedaf2e92ba255a4ee95967a04a918
Contents?: true
Size: 1.71 KB
Versions: 16
Compression:
Stored size: 1.71 KB
Contents
# frozen_string_literal: true
module RuboCop
module Cop
module Rails
# This cop enforces the use of `pluck` over `map`.
#
# `pluck` can be used instead of `map` to extract a single key from each
# element in an enumerable. When called on an Active Record relation, it
# results in a more efficient query that only selects the necessary key.
#
# @example
# # bad
# Post.published.map { |post| post[:title] }
# [{ a: :b, c: :d }].collect { |el| el[:a] }
#
# # good
# Post.published.pluck(:title)
# [{ a: :b, c: :d }].pluck(:a)
class Pluck < Base
extend AutoCorrector
extend TargetRailsVersion
MSG = 'Prefer `pluck(:%<value>s)` over `%<method>s { |%<argument>s| %<element>s[:%<value>s] }`.'
minimum_target_rails_version 5.0
def_node_matcher :pluck_candidate?, <<~PATTERN
(block (send _ ${:map :collect}) (args (arg $_argument)) (send (lvar $_element) :[] (sym $_value)))
PATTERN
def on_block(node)
pluck_candidate?(node) do |method, argument, element, value|
next unless argument == element
message = message(method, argument, element, value)
add_offense(offense_range(node), message: message) do |corrector|
corrector.replace(offense_range(node), "pluck(:#{value})")
end
end
end
private
def offense_range(node)
node.send_node.loc.selector.join(node.loc.end)
end
def message(method, argument, element, value)
format(MSG, method: method, argument: argument, element: element, value: value)
end
end
end
end
end
Version data entries
16 entries across 16 versions & 1 rubygems