broken_case.rb

# 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", '~> 6.1.0'
  gem "sqlite3"
end

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

# This connection will do for database-independent bug reports.
db = Tempfile.new(['db', '.db'])
ActiveRecord::Base.configurations = {
  primary: { adapter: "sqlite3", database: db },
  primary_replica: { adapter: "sqlite3", database: db }
}

ActiveRecord::Base.legacy_connection_handling = false
ActiveRecord::Base.establish_connection(:primary)
ActiveRecord::Base.logger = Logger.new(STDOUT)

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

ActiveRecord::Base.connects_to(
  database: {
    writing: :primary,
    reading: :primary_replica
  }
)

class BaseRecord < ActiveRecord::Base
  self.abstract_class = true
end

class User < BaseRecord
end

class BugTest < Minitest::Test
  include ActiveRecord::TestFixtures

  def test_readonly
    BaseRecord.connected_to(role: :reading) do
      # expected true, got false
      assert User.connection.preventing_writes?

      # ActiveRecord::ReadOnlyError expected but nothing was raised.
      assert_raises(ActiveRecord::ReadOnlyError) do
        User.create!
      end
    end
  end
end