Rails 7 adds maximum and minimum methods to Enumerable

Rails 7 adds Enumerable#maximum and Enumerable#minimum to easily calculate the maximum or minimum from extracted elements of an enumerable.

Let’s say we have a model called Product with an attribute price.

# app/models/product.rb
class Product < ApplicationRecord
  attr_reader :price

Now we need to get the maximum or minimum value of price for an array of products.


We would get the minimum and maximum value using:

  products = [Product.new(price: 20), Product.new(price: 33), Product.new(price: 22)]
  minimum = products.pluck(:price).min # => 20
  maximum = products.pluck(:price).max # => 33

In the case of an ActiveRecord Collection, we could achieve this just by using maximum and minimum directly on the collection as these methods are defined in the ActiveRecord::Calculations library.


Rails 7 added maximum and minimum methods in the Enumerable module. Hence they can be used directly on all enumerable.

So from the above example,

  products = [Product.new(price: 20), Product.new(price: 33), Product.new(price: 22)]
  minimum = products.minimum(:price) # => 20
  maximum = products.maximum(:price) # => 33

This is a simple enhancement, but it helps a lot when we have to deal with enumerable directly and not ActiveRecord Collection objects.