rails: Rails 7 is not clearing query cache

I believe I am hitting this.

I generated a vanilla Rails 7 application with a User model and wrote this test:

class UserTest < ActiveSupport::TestCase
  test "INSERT with execute" do
    assert_difference "User.count", 1 do
      User.connection.execute("INSERT INTO users (name) VALUES ('John Smith')")
    end
  end
end

This test fails, and the reason is the second User.count hits the query cache.

If execute is not invalidating the cache, I think it should.

@fxn yeah, I meant to do it, but it requires a significant refactor of the MySQL2 adapter has it uses execute both internally and externally, and even for other adapters, they all have their own execute implementation, it’s a bit of a mess.

In the meantime, the better method to use in your case is:

class UserTest < ActiveSupport::TestCase
  test "INSERT with execute" do
    assert_difference "User.count", 1 do
      User.connection.insert("INSERT INTO users (name) VALUES ('John Smith')")
    end
  end
end

Executable test case:

# frozen_string_literal: true

require "bundler/inline"

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

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

  gem "rails", github: "rails/rails", branch: "main"
  gem "sqlite3"
end

require "rails/all"
require "minitest/autorun"
require "logger"

class TestApp < Rails::Application
  config.root = __dir__
  config.hosts << "example.org"
  config.eager_load = false
  config.session_store :cookie_store, key: "cookie_store_key"
  secrets.secret_key_base = "secret_key_base"

  config.logger = Logger.new($stdout)
  Rails.logger  = config.logger

  config.active_support.executor_around_test_case = true
end

ENV["DATABASE_URL"] = "sqlite3::memory:"

Rails.application.initialize!

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.text :name
  end
end

class User < ActiveRecord::Base
end

class BugTest < ActiveSupport::TestCase
  def test_stuff
    assert_equal [], User.pluck(:name)
    ActiveRecord::Base.connection.execute "INSERT INTO users (name) VALUES (1)"
    assert_equal ["1"], User.pluck(:name)
  end
end

If you change line 28, the test passes.

The pertinent difference between load_defaults 6.1 and 7.0 is active_support.executor_around_test_case. With:

config.load_defaults 7.0
config.active_support.executor_around_test_case = false

the problem no longer occurs.

So I guess my question would be: is it expected behaviour for ActiveRecord#connection#execute to not clear the query cache?