Testing scopes with Rails

class User < ActiveRecord::Base  scope :newest, -> { order(created_at: :asc) }  scope :oldest, -> { order(created_at: :desc) }end

class UserTest < ActiveSupport::TestCase  def setup    @user_one = User.create!(created_at: 1.day.ago)    @user_two = User.create!(created_at: 2.days.ago)    @user_three = User.create!(created_at: 3.days.ago)    # This lets us have a known set of data. We don't have a polluted global scope of users.    @users = User.where(id: [@user_one.id, @user_two.id, @user_three.id])  endend

class UserTest < ActiveSupport::TestCase  def setup    # ...  end  test "Newest users and oldest users should be sorted properly" do    # By testing both newest and oldest, we're coupling these tests together    # We test both just in case our records just happen to be returned in the correct order.    # we could use reverse_scope to test newest, but instead we just make this explicit.    # chain off of @users so we use a known set of data rather than the whole database.    newest_users = @users.newest    assert_operator newest_users.first.created_at, :>=, newest_users.second.created_at    assert_operator newest_users.first.created_at, :>=, newest_users.third.created_at    assert_operator newest_users.second.created_at, :>=, newest_users.third.created_at    oldest_users = @users.oldest    assert_operator oldest_users.first.created_at, :<=, oldest_users.second.created_at    assert_operator oldest_users.first.created_at, :<=, oldest_users.third.created_at    assert_operator oldest_users.second.created_at, :<=, oldest_users.third.created_at  endend

ruby user_test.rb# Running:FFinished in 0.013149s, 76.0489 runs/s, 76.0489 assertions/s.  1) Failure:UserTest#test_Newest_users_and_oldest_users_should_be_sorted_properly [single_line_active_record.rb:52]:Expected 2022-04-05 18:15:24.185615 UTC to be >= 2022-04-06 18:15:24.184933 UTC.

class User < ActiveRecord::Base-  scope :newest, -> { order(created_at: :asc) }+  scope :newest, -> { order(created_at: :desc) }-  scope :oldest, -> { order(created_at: :desc) }+  scope :oldest, -> { order(created_at: :asc) }end

ruby user_test.rb# Running:.Finished in 0.021307s, 46.9331 runs/s, 281.5983 assertions/s.1 runs, 6 assertions, 0 failures, 0 errors, 0 skips

class User < ApplicationRecord  scope :created_after, ->(date) { where("created_at >= ?", date) }end

class UserTest < ActiveSupport::TestCase  test "Should only show users created from 2 days ago and later" do    # Always use beginning of day. I believe 2.days.ago drops the "time" causing it to act like    # #end_of_day which will cause our user created "2.days.ago" to be excluded.    users = @users.created_after(2.days.ago.beginning_of_day)    # We know there should only be 2 users created within the last 2 days.    assert_equal users.size, 2    assert_includes users, @user_one    assert_includes users, @user_two  endend

$ ruby user_test.rb# Running:..Finished in 0.024298s, 82.3114 runs/s, 452.7127 assertions/s.2 runs, 11 assertions, 0 failures, 0 errors, 0 skips