Rails group/count key type bug test case

docker-compose.yml

services:
  postgres:
    image: postgres
    healthcheck:
      test: ["CMD", "pg_isready"]
    environment:
      - POSTGRES_HOST_AUTH_METHOD=trust
  test:
    image: rails-group-by-test
    build: ./.
    depends_on:
      postgres:
        condition: service_healthy
    environment:
      DATABASE_URL: postgres://postgres@postgres/postgres
    volumes:
      - bundler:/usr/local/bundle
volumes:
  bundler:

Dockerfile

FROM ruby:3.2

COPY group-by-test.rb /

CMD "ruby" "/group-by-test.rb"

group-by-test.rb

# frozen_string_literal: true
#
# Requires a postgres database, for example
#
#     createdb group_by_test
#     DATABASE_URL=postgres://localhost/group-by-test ruby ./group-by-test.rb
#
# Also supports checking other Rails versions via the RAILS_VERSION
# environment variable. For example:
#
#     createdb group_by_test
#     RAILS_VERSION=7.0.4.3 DATABASE_URL=postgres://localhost/group-by-test ruby ./group-by-test.rb

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  if (rails_version = ENV['RAILS_VERSION'])
    gem "rails", rails_version
  else
    gem "rails", github: "rails/rails", branch: "main"
  end

  gem "pg"

  gem 'timeout', '=0.3.2' # workaround for bundler/inline
end

require "active_record"
require "minitest/autorun"
require "logger"

ActiveRecord::Base.establish_connection
# ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :bookings, force: true
end

class Booking < ActiveRecord::Base
end

class BugTest < Minitest::Test
  def setup
    Booking.create!
  end

  def teardown
    Booking.delete_all
  end

  def test_group_by
    grouped_count =
      Booking
        .group("tsrange(timestamp '2020-01-01', timestamp '2020-01-02', '[)') ")
        .count(:id)

    assert_equal Range, grouped_count.keys.first.class # passes
  end

  def test_group_by_join
    grouped_count =
      Booking
        .joins("JOIN (SELECT tsrange(timestamp '2020-01-01', timestamp '2020-01-02', '[)') AS range) ranges ON TRUE")
        .group('ranges.range')
        .count(:id)

    assert_equal Range, grouped_count.keys.first.class # fails
  end
end

Rails 7.0.4.3

❯ RAILS_VERSION=7.0.4.3 DATABASE_URL=postgres://localhost/group-by-test ruby ./group-by-test.rb
[...]
Using rails 7.0.4.3
[...]
# Running:

..

Finished in 0.009883s, 202.3589 runs/s, 202.3589 assertions/s.
2 runs, 2 assertions, 0 failures, 0 errors, 0 skips

Rails 7.0.5

❯ RAILS_VERSION=7.0.5 DATABASE_URL=postgres://localhost/group-by-test ruby ./group-by-test.rb
[...]
Using rails 7.0.5
[...]
# Running:

.F

Failure:
BugTest#test_group_by_join [./group-by-test.rb:76]:
Expected: Range
  Actual: String


rails test ./group-by-test.rb:69



Finished in 0.010084s, 198.3436 runs/s, 198.3436 assertions/s.
2 runs, 2 assertions, 1 failures, 0 errors, 0 skips

Rails master

❯ DATABASE_URL=postgres://localhost/group-by-test ruby ./group-by-test.rb
[...]
Using rails 7.1.0.alpha from https://github.com/rails/rails.git (at main@55c3066)
[...]
# Running:

.F

Failure:
BugTest#test_group_by_join [./group-by-test.rb:76]:
Expected: Range
  Actual: String


bin/rails test ./group-by-test.rb:69



Finished in 0.013512s, 148.0131 runs/s, 148.0131 assertions/s.
2 runs, 2 assertions, 1 failures, 0 errors, 0 skips