# config/database.yml
test:
  adapter: postgresql
  encoding: unicode
  database: myapp_test
  pool: 5
  username: myapp
  password: password
  host: localhost

rake db:create RAILS_ENV=test
rake db:migrate RAILS_ENV=test

# Gemfile
group :test do
  gem 'database_cleaner'
end

# spec/spec_helper.rb or test/test_helper.rb
RSpec.configure do |config|
  config.before(:suite) do
    DatabaseCleaner.strategy = :transaction
    DatabaseCleaner.clean_with(:truncation)
  end

  config.around(:each) do |example|
    DatabaseCleaner.cleaning do
      example.run
    end
  end
end

# config/database.yml
test:
  adapter: sqlite3
  database: ":memory:"
  pool: 5
  timeout: 5000

# Gemfile
group :test do
  gem 'factory_bot_rails'
end

# spec/factories/users.rb
FactoryBot.define do
  factory :user do
    name { "Test User" }
    email { "test@example.com" }
    password { "password" }
  end
end

# 在测试中使用
user = create(:user)

RAILS_ENV=test rake db:create db:migrate

after(:each) do
  User.destroy_all
end

# spec/spec_helper.rb
RSpec.configure do |config|
  config.shared_context_metadata_behavior = :apply_to_host_groups
end