diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb index b4377ad6beb..d43378c64f3 100644 --- a/activerecord/lib/active_record.rb +++ b/activerecord/lib/active_record.rb @@ -163,6 +163,7 @@ module ActiveRecord "active_record/tasks/postgresql_database_tasks" end + autoload :TestDatabases, "active_record/test_databases" autoload :TestFixtures, "active_record/fixtures" def self.eager_load! diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb index d9a75d9ad67..8f022ff7a7a 100644 --- a/activerecord/lib/active_record/fixtures.rb +++ b/activerecord/lib/active_record/fixtures.rb @@ -874,6 +874,7 @@ module ActiveRecord class_attribute :use_instantiated_fixtures, default: false # true, false, or :no_instances class_attribute :pre_loaded_fixtures, default: false class_attribute :config, default: ActiveRecord::Base + class_attribute :lock_threads, default: true end module ClassMethods @@ -973,7 +974,7 @@ module ActiveRecord @fixture_connections = enlist_fixture_connections @fixture_connections.each do |connection| connection.begin_transaction joinable: false - connection.pool.lock_thread = true + connection.pool.lock_thread = true if lock_threads end # When connections are established in the future, begin a transaction too @@ -989,7 +990,7 @@ module ActiveRecord if connection && !@fixture_connections.include?(connection) connection.begin_transaction joinable: false - connection.pool.lock_thread = true + connection.pool.lock_thread = true if lock_threads @fixture_connections << connection end end diff --git a/activerecord/lib/active_record/test_databases.rb b/activerecord/lib/active_record/test_databases.rb new file mode 100644 index 00000000000..606a3b0fb50 --- /dev/null +++ b/activerecord/lib/active_record/test_databases.rb @@ -0,0 +1,38 @@ +# frozen_string_literal: true + +require "active_support/testing/parallelization" + +module ActiveRecord + module TestDatabases # :nodoc: + ActiveSupport::Testing::Parallelization.after_fork_hook do |i| + create_and_migrate(i, spec_name: Rails.env) + end + + ActiveSupport::Testing::Parallelization.run_cleanup_hook do |i| + drop(i, spec_name: Rails.env) + end + + def self.create_and_migrate(i, spec_name:) + old, ENV["VERBOSE"] = ENV["VERBOSE"], "false" + + connection_spec = ActiveRecord::Base.configurations[spec_name] + + connection_spec["database"] += "-#{i}" + ActiveRecord::Tasks::DatabaseTasks.create(connection_spec) + ActiveRecord::Base.establish_connection(connection_spec) + ActiveRecord::Tasks::DatabaseTasks.migrate + ensure + ActiveRecord::Base.establish_connection(ActiveRecord::Base.configurations[Rails.env]) + ENV["VERBOSE"] = old + end + + def self.drop(i, spec_name:) + old, ENV["VERBOSE"] = ENV["VERBOSE"], "false" + connection_spec = ActiveRecord::Base.configurations[spec_name] + + ActiveRecord::Tasks::DatabaseTasks.drop(connection_spec) + ensure + ENV["VERBOSE"] = old + end + end +end diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md index fc47c76e99f..2976040a59c 100644 --- a/activesupport/CHANGELOG.md +++ b/activesupport/CHANGELOG.md @@ -1,2 +1,7 @@ +* Adds parallel testing to Rails + + Parallelize your test suite with forked processes or threads. + + *Eileen M. Uchitelle*, *Aaron Patterson* Please check [5-2-stable](https://github.com/rails/rails/blob/5-2-stable/activesupport/CHANGELOG.md) for previous changes. diff --git a/activesupport/lib/active_support/test_case.rb b/activesupport/lib/active_support/test_case.rb index d1f7e6ea095..3588a5ac021 100644 --- a/activesupport/lib/active_support/test_case.rb +++ b/activesupport/lib/active_support/test_case.rb @@ -11,6 +11,7 @@ require "active_support/testing/isolation" require "active_support/testing/constant_lookup" require "active_support/testing/time_helpers" require "active_support/testing/file_fixtures" +require "active_support/testing/parallelization" module ActiveSupport class TestCase < ::Minitest::Test @@ -39,6 +40,91 @@ module ActiveSupport def test_order ActiveSupport.test_order ||= :random end + + # Parallelizes the test suite. + # + # Takes a `workers` argument that controls how many times the process + # is forked. For each process a new database will be created suffixed + # with the worker number. + # + # test-database-0 + # test-database-1 + # + # If `ENV["PARALLEL_WORKERS"]` is set the workers argument will be ignored + # and the environment variable will be used instead. This is useful for CI + # environments, or other environments where you may need more workers than + # you do for local testing. + # + # If the number of workers is set to `1` or fewer, the tests will not be + # parallelized. + # + # The default parallelization method is to fork processes. If you'd like to + # use threads instead you can pass `with: :threads` to the `parallelize` + # method. Note the threaded parallelization does not create multiple + # database and will not work with system tests at this time. + # + # parallelize(workers: 2, with: :threads) + # + # The threaded parallelization uses Minitest's parallel exector directly. + # The processes paralleliztion uses a Ruby Drb server. + def parallelize(workers: 2, with: :processes) + workers = ENV["PARALLEL_WORKERS"].to_i if ENV["PARALLEL_WORKERS"] + + return if workers <= 1 + + executor = case with + when :processes + Testing::Parallelization.new(workers) + when :threads + Minitest::Parallel::Executor.new(workers) + else + raise ArgumentError, "#{with} is not a supported parallelization exectutor." + end + + self.lock_threads = false if defined?(self.lock_threads) && with == :threads + + Minitest.parallel_executor = executor + + parallelize_me! + end + + # Set up hook for parallel testing. This can be used if you have multiple + # databases or any behavior that needs to be run after the process is forked + # but before the tests run. + # + # Note: this feature is not available with the threaded parallelization. + # + # In your +test_helper.rb+ add the following: + # + # class ActiveSupport::TestCase + # parallelize_setup do + # # create databases + # end + # end + def parallelize_setup(&block) + ActiveSupport::Testing::Parallelization.after_fork_hook do |worker| + yield worker + end + end + + # Clean up hook for parallel testing. This can be used to drop databases + # if your app uses multiple write/read databases or other clean up before + # the tests finish. This runs before the forked process is closed. + # + # Note: this feature is not available with the threaded parallelization. + # + # In your +test_helper.rb+ add the following: + # + # class ActiveSupport::TestCase + # parallelize_teardown do + # # drop databases + # end + # end + def parallelize_teardown(&block) + ActiveSupport::Testing::Parallelization.run_cleanup_hook do |worker| + yield worker + end + end end alias_method :method_name, :name diff --git a/activesupport/lib/active_support/testing/parallelization.rb b/activesupport/lib/active_support/testing/parallelization.rb new file mode 100644 index 00000000000..59c8486f41c --- /dev/null +++ b/activesupport/lib/active_support/testing/parallelization.rb @@ -0,0 +1,102 @@ +# frozen_string_literal: true + +require "drb" +require "drb/unix" + +module ActiveSupport + module Testing + class Parallelization # :nodoc: + class Server + include DRb::DRbUndumped + + def initialize + @queue = Queue.new + end + + def record(reporter, result) + reporter.synchronize do + reporter.record(result) + end + end + + def <<(o) + @queue << o + end + + def pop; @queue.pop; end + end + + @after_fork_hooks = [] + + def self.after_fork_hook(&blk) + @after_fork_hooks << blk + end + + def self.after_fork_hooks + @after_fork_hooks + end + + @run_cleanup_hooks = [] + + def self.run_cleanup_hook(&blk) + @run_cleanup_hooks << blk + end + + def self.run_cleanup_hooks + @run_cleanup_hooks + end + + def initialize(queue_size) + @queue_size = queue_size + @queue = Server.new + @pool = [] + + @url = DRb.start_service("drbunix:", @queue).uri + end + + def after_fork(worker) + self.class.after_fork_hooks.each do |cb| + cb.call(worker) + end + end + + def run_cleanup(worker) + self.class.run_cleanup_hooks.each do |cb| + cb.call(worker) + end + end + + def start + @pool = @queue_size.times.map do |worker| + fork do + DRb.stop_service + + after_fork(worker) + + queue = DRbObject.new_with_uri(@url) + + while job = queue.pop + klass = job[0] + method = job[1] + reporter = job[2] + result = Minitest.run_one_method(klass, method) + + queue.record(reporter, result) + end + + run_cleanup(worker) + end + end + end + + def <<(work) + @queue << work + end + + def shutdown + @queue_size.times { @queue << nil } + @pool.each { |pid| Process.waitpid pid } + end + end + end +end diff --git a/guides/source/testing.md b/guides/source/testing.md index af6127f4a5d..5d2b8bc5d65 100644 --- a/guides/source/testing.md +++ b/guides/source/testing.md @@ -462,6 +462,89 @@ Rails options: -c, --[no-]color Enable color in the output ``` +Parallel Testing +---------------- + +Parallel testing allows you to parallelize your test suite. While forking processes is the +default method, threading is supported as well. Running tests in parallel reduces the time it +takes your entire test suite to run. + +## Parallel testing with processes + +The default parallelization method is to fork processes using Ruby's DRb system. The processes +are forked based on the number of workers provided. The default is 2, but can be changed by the +number passed to the parallelize method. Active Record automatically handles creating and +migrating a new database for each worker to use. + +To enable parallelization add the following to your `test_helper.rb`: + +``` +class ActiveSupport::TestCase + parallelize(workers: 2) +end +``` + +The number of workers passed is the number of times the process will be forked. You may want to +parallelize your local test suite differently from your CI, so an environment variable is provided +to be able to easily change the number of workers a test run should use: + +``` +PARALLEL_WORKERS=15 bin/rails test +``` + +When parallelizing tests, Active Record automatically handles creating and migrating a database for each +process. The databases will be suffixed with the number corresponding to the worker. For example, if you +have 2 workers the tests will create `test-database-0` and `test-database-1` respectively. + +If the number of workers passed is 1 or fewer the processes will not be forked and the tests will not +be parallelized and the tests will use the original `test-database` database. + +Two hooks are provided, one runs when the process is forked, and one runs before the processes are closed. +These can be useful if your app uses multiple databases or perform other tasks that depend on the number of +workers. + +The `parallelize_setup` method is called right after the processes are forked. The `parallelize_teardown` metod +is called right before the processes are closed. + +``` +class ActiveSupport::TestCase + parallelize_setup do |worker| + # setup databases + end + + parallelize_teardown do |worker| + # cleanup database + end + + parallelize(workers: 2) +end +``` + +These methods are not needed or available when using parallel testing with threads. + +## Parallel testing with threads + +If you prefer using threads or are using JRuby, a threaded parallelization option is provided. The threaded +parallelizer is backed by Minitest's `Parallel::Executor`. + +To change the parallelization method to use threads over forks put the following in your `test_helper.rb` + +``` +class ActiveSupport::TestCase + parallelize(workers: 2, with: :threads) +end +``` + +Rails applications generated from JRuby will automatically include the `with: :threads` option. + +The number of workers passed to `parallelize` determines the number of threads the tests will use. You may +want to parallelize your local test suite differently from your CI, so an environment variable is provided +to be able to easily change the number of workers a test run should use: + +``` +PARALLEL_WORKERS=15 bin/rails test +``` + The Test Database ----------------- diff --git a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt index 52d68cc77ce..c918b57ecaa 100644 --- a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt +++ b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt @@ -3,6 +3,13 @@ require_relative '../config/environment' require 'rails/test_help' class ActiveSupport::TestCase + # Run tests in parallel with specified workers +<% if defined?(JRUBY_VERSION) -%> + parallelize(workers: 2, with: :threads) +<%- else -%> + parallelize(workers: 2) +<% end -%> + <% unless options[:skip_active_record] -%> # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order. fixtures :all diff --git a/railties/lib/rails/test_help.rb b/railties/lib/rails/test_help.rb index 76c28ac85ef..4bd7d74b044 100644 --- a/railties/lib/rails/test_help.rb +++ b/railties/lib/rails/test_help.rb @@ -22,6 +22,7 @@ if defined?(ActiveRecord::Base) module ActiveSupport class TestCase + include ActiveRecord::TestDatabases include ActiveRecord::TestFixtures self.fixture_path = "#{Rails.root}/test/fixtures/" self.file_fixture_path = fixture_path + "files" diff --git a/railties/test/application/test_runner_test.rb b/railties/test/application/test_runner_test.rb index a01325fdb89..fe1dd59990b 100644 --- a/railties/test/application/test_runner_test.rb +++ b/railties/test/application/test_runner_test.rb @@ -502,10 +502,10 @@ module ApplicationTests end def test_output_inline_by_default - create_test_file :models, "post", pass: false + create_test_file :models, "post", pass: false, print: false output = run_test_command("test/models/post_test.rb") - expect = %r{Running:\n\nPostTest\nF\n\nFailure:\nPostTest#test_truth \[[^\]]+test/models/post_test.rb:6\]:\nwups!\n\nbin/rails test test/models/post_test.rb:4\n\n\n\n} + expect = %r{Running:\n\nF\n\nFailure:\nPostTest#test_truth \[[^\]]+test/models/post_test.rb:6\]:\nwups!\n\nbin/rails test test/models/post_test.rb:4\n\n\n\n} assert_match expect, output end @@ -523,6 +523,29 @@ module ApplicationTests capture(:stderr) { run_test_command("test/models/post_test.rb --fail-fast", stderr: true) }) end + def test_run_in_parallel_with_processes + file_name = create_parallel_processes_test_file + + output = run_test_command(file_name) + + assert_match %r{Finished in.*\n2 runs, 2 assertions}, output + end + + def test_run_in_parallel_with_threads + app_path("/test/test_helper.rb") do |file_name| + file = File.read(file_name) + file.sub!(/parallelize\(([^\)]*)\)/, "parallelize(\\1, with: :threads)") + puts file + File.write(file_name, file) + end + + file_name = create_parallel_threads_test_file + + output = run_test_command(file_name) + + assert_match %r{Finished in.*\n2 runs, 2 assertions}, output + end + def test_raise_error_when_specified_file_does_not_exist error = capture(:stderr) { run_test_command("test/not_exists.rb", stderr: true) } assert_match(%r{cannot load such file.+test/not_exists\.rb}, error) @@ -800,19 +823,70 @@ module ApplicationTests RUBY end - def create_test_file(path = :unit, name = "test", pass: true) + def create_test_file(path = :unit, name = "test", pass: true, print: true) app_file "test/#{path}/#{name}_test.rb", <<-RUBY require 'test_helper' class #{name.camelize}Test < ActiveSupport::TestCase def test_truth - puts "#{name.camelize}Test" + puts "#{name.camelize}Test" if #{print} assert #{pass}, 'wups!' end end RUBY end + def create_parallel_processes_test_file + app_file "test/models/parallel_test.rb", <<-RUBY + require 'test_helper' + + class ParallelTest < ActiveSupport::TestCase + RD1, WR1 = IO.pipe + RD2, WR2 = IO.pipe + + test "one" do + WR1.close + assert_equal "x", RD1.read(1) # blocks until two runs + + RD2.close + WR2.write "y" # Allow two to run + WR2.close + end + + test "two" do + RD1.close + WR1.write "x" # Allow one to run + WR1.close + + WR2.close + assert_equal "y", RD2.read(1) # blocks until one runs + end + end + RUBY + end + + def create_parallel_threads_test_file + app_file "test/models/parallel_test.rb", <<-RUBY + require 'test_helper' + + class ParallelTest < ActiveSupport::TestCase + Q1 = Queue.new + Q2 = Queue.new + test "one" do + assert_equal "x", Q1.pop # blocks until two runs + + Q2 << "y" + end + + test "two" do + Q1 << "x" + + assert_equal "y", Q2.pop # blocks until one runs + end + end + RUBY + end + def create_env_test app_file "test/unit/env_test.rb", <<-RUBY require 'test_helper' diff --git a/railties/test/application/test_test.rb b/railties/test/application/test_test.rb index 0a51e986565..fb43bebfbec 100644 --- a/railties/test/application/test_test.rb +++ b/railties/test/application/test_test.rb @@ -7,10 +7,15 @@ module ApplicationTests include ActiveSupport::Testing::Isolation def setup + @old = ENV["PARALLEL_WORKERS"] + ENV["PARALLEL_WORKERS"] = "0" + build_app end def teardown + ENV["PARALLEL_WORKERS"] = @old + teardown_app end diff --git a/railties/test/isolation/abstract_unit.rb b/railties/test/isolation/abstract_unit.rb index 6568a356d64..0a4d2a91675 100644 --- a/railties/test/isolation/abstract_unit.rb +++ b/railties/test/isolation/abstract_unit.rb @@ -38,7 +38,12 @@ module TestHelpers end def app_path(*args) - tmp_path(*%w[app] + args) + path = tmp_path(*%w[app] + args) + if block_given? + yield path + else + path + end end def framework_path