邮件列表上的答案基本上是自己动手的情况,所以如果他们最终也不得不这样做,可以为其他人省去麻烦:
在 lib/tasks 下创建一个 .rake 文件,名为 test_db_setup.rake:
require File.dirname(__FILE__) + '/../../test/database_dumper'
# Custom logic that runs before the test suite begins
# This just clones the development database schema to the test database
# Note that each test does a lightweight teardown of just truncating all tables
namespace :db do
namespace :test do
desc "Reset the test database to match the development schema"
task :prepare do
Rake::Task['db:schema:clone'].invoke
end
end
namespace :schema do
desc "Literally dump the database schema into db/schema/**/*.sql"
task :dump => :environment do
DatabaseDumper.dump_schema(:directory => "#{Rails.root}/db/schema", :env => Rails.env)
end
desc "Clones the development schema into the test database"
task :clone => [:dump, :environment] do
DatabaseDumper.import_schema(:directory => "#{Rails.root}/db/schema", :env => "test")
end
end
end
task 'test:prepare' => 'db:test:prepare'
这使用了:test:prepare
Rails 提供的钩子,它在测试套件开始之前运行。它将模式从您的开发数据库复制到 db/schema/ 下的 .sql 文件(每个表/视图一个),然后将这些 .sql 文件导入您的测试数据库。
您需要我为此编写的实用程序类(目前它是为 MySQL >= 5.0.1 编写的。如果您需要不同的数据库,则必须调整逻辑。
# Utility class for dumping and importing the database schema
class DatabaseDumper
def self.dump_schema(options = {})
options[:directory] ||= "#{Rails.root}/db/schema"
options[:env] ||= Rails.env
schema_dir = options[:directory]
clean_sql_directory(schema_dir)
Rails::DataMapper.configuration.repositories[options[:env]].each do |repository, config|
repository_dir = "#{schema_dir}/#{repository}"
adapter = DataMapper.setup(repository, config)
perform_schema_dump(adapter, repository_dir)
end
end
def self.import_schema(options = {})
options[:directory] ||= "#{Rails.root}/db/schema"
options[:env] ||= "test"
schema_dir = options[:directory]
Rails::DataMapper.configuration.repositories[options[:env]].each do |repository, config|
repository_dir = "#{schema_dir}/#{repository}"
adapter = DataMapper.setup(repository, config)
perform_schema_import(adapter, repository_dir)
end
end
private
def self.clean_sql_directory(path)
Dir.mkdir(path) unless Dir.exists?(path)
Dir.glob("#{path}/**/*.sql").each do |file|
File.delete(file)
end
end
def self.perform_schema_dump(adapter, path)
Dir.mkdir(path) unless Dir.exists?(path)
adapter.select("SHOW FULL TABLES").each do |row|
name = row.values.first
type = row.values.last
sql_dir = "#{path}/#{directory_name_for_table_type(type)}"
Dir.mkdir(sql_dir) unless Dir.exists?(sql_dir)
schema_info = adapter.select("SHOW CREATE TABLE #{name}").first
sql = schema_info.values.last
f = File.open("#{sql_dir}/#{name}.sql", "w+")
f << sql << "\n"
f.close
end
end
def self.directory_name_for_table_type(type)
case type
when "VIEW"
"views"
when "BASE TABLE"
"tables"
else
raise "Unknown table type #{type}"
end
end
def self.perform_schema_import(adapter, path)
tables_dir = "#{path}/tables"
views_dir = "#{path}/views"
{ "TABLE" => tables_dir, "VIEW" => views_dir }.each do |type, sql_dir|
Dir.glob("#{sql_dir}/*.sql").each do |file|
name = File.basename(file, ".sql")
drop_sql = "DROP #{type} IF EXISTS `#{name}`"
create_sql = File.open(file, "r").read
adapter.execute(drop_sql)
adapter.execute(create_sql)
end
end
end
end
这也会将 .sql 文件保留在您的架构目录中,因此您可以在需要参考时浏览它们。
现在这只会在测试套件启动时擦除您的数据库(通过安装新模式)。它不会擦除测试方法之间的测试。为此,您需要使用DatabaseCleaner。把它放在你的 test_helper.rb 中:
require 'database_cleaner'
DatabaseCleaner.strategy = :truncation, {:except => %w(auctionindexview helpindexview)}
class ActiveSupport::TestCase
setup :setup_database
teardown :clean_database
private
def setup_database
DatabaseCleaner.start
end
def clean_database
DatabaseCleaner.clean
end
end
现在你应该可以走了。当您开始运行测试时,您的模式将是新鲜的,您将在 db/schema 目录中拥有 SQL 的副本,并且您的数据将在测试方法之间擦除。如果您被 DatabaseCleaner 的事务策略所吸引,请注意……这在 MySQL 中使用很少是安全的策略,因为目前没有任何 MySQL 表类型支持嵌套事务,因此您的应用程序逻辑可能会破坏拆解. 截断仍然很快,而且更安全。