Class: RuboCop::Cop::Rails::IndexBy

Inherits:

Base

Object
Base
RuboCop::Cop::Rails::IndexBy

show all

Extended by:: AutoCorrector

Includes:: IndexMethod

Defined in:: lib/rubocop/cop/rails/index_by.rb

Overview

Looks for uses of ‘each_with_object({}) { … }`, `map { … }.to_h`, and `Hash[map { … }]` that are transforming an enumerable into a hash where the values are the original elements. Rails provides the `index_by` method for this purpose.

Examples:

# bad
[1, 2, 3].each_with_object({}) { |el, h| h[foo(el)] = el }
[1, 2, 3].to_h { |el| [foo(el), el] }
[1, 2, 3].map { |el| [foo(el), el] }.to_h
Hash[[1, 2, 3].collect { |el| [foo(el), el] }]

# good
[1, 2, 3].index_by { |el| foo(el) }

Constant Summary

Constants included from IndexMethod

IndexMethod::RESTRICT_ON_SEND

Method Summary

Methods included from IndexMethod

#on_block, #on_csend, #on_send