Wrapping ActiveRecord test causes it to fail (no records found)

Bắt đầu bằng cách chạy bản tái hiện Ruby được cung cấp với ActiveRecord 4.2.7.1, mysql2, DatabaseCleaner và RSpec, sau đó so sánh các ví dụ text_search và like_search trong từng chế độ dọn dẹp. Hoàn thành khi các ví dụ text_search không còn thất bại với lỗi không tìm thấy bản ghi và hành vi dọn dẹp hiện có vẫn được bao phủ.

I created a script to demonstrate this behavior:

#!/usr/bin/env ruby

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"
  gem "activerecord", "4.2.7.1"
  gem "mysql2", "0.4.5"
  gem "database_cleaner", "1.5.3"
  gem "rspec", "3.5.0"
end

require "active_record"
require "rspec"
require "rspec/autorun"
require "database_cleaner"

ActiveRecord::Base.establish_connection(
  adapter: "mysql2",
  username: "root",
  password: "password",
  host: "localhost",
  database: "ft_test"
)
ActiveRecord::Base.connection.recreate_database "ft_test"

ActiveRecord::Schema.define do
  create_table :widgets, force: true do |t|
    t.string "description", limit: 255
  end

  add_index "widgets", ["description"], name: "widgets_description_fts", type: :fulltext
end

class Widget < ActiveRecord::Base
  def self.text_search(query)
    where("MATCH(description) AGAINST(:query)", query: query)
  end

  def self.like_search(query)
    where("description like ?", "%#{query}%")
  end
end

RSpec.configure do |config|
  config.default_formatter = "doc"
  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end
  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end
end

RSpec.describe Widget, type: :model do
  describe ".text_search" do
    after(:all) { Widget.delete_all }
    it "fails when cleaning with start/clean" do
      DatabaseCleaner.start

      text_search_test

      DatabaseCleaner.clean
    end

    it "fails when cleaning with block" do
      DatabaseCleaner.cleaning do
        text_search_test
      end
    end

    it "succeeds with manual cleaning (fails at random, unless it is first or the only test run)" do
      Widget.delete_all

      text_search_test

      Widget.delete_all
    end
  end

  describe ".like_search" do
    it "succeeds when cleaning with start/clean" do
      DatabaseCleaner.start

      like_search_test

      DatabaseCleaner.clean
    end

    it "succeeds when cleaning with block" do
      DatabaseCleaner.cleaning do
        like_search_test
      end
    end

    it "succeeds with manual cleaning" do
      Widget.delete_all

      like_search_test

      Widget.delete_all
    end
  end

  private

  def create_widgets
    Widget.create()
    match = Widget.create(description: "The quick brown fox jumps over the lazy dog")
    Widget.create()

    match
  end

  def text_search_test
    match = create_widgets
    expect(Widget.text_search("fox")).to contain_exactly match
  end

  def like_search_test
    match = create_widgets
    expect(Widget.like_search("fox")).to contain_exactly match
  end
end