CI: Run tests in parallel

GitHub Actions have two cores by default. Let's use them.

Author: tvdeyen

.github/workflows/build_test.yml

@@ -200,9 +200,12 @@ jobs:
       - name: Prepare database
         run: |
           bundle exec rake alchemy:spec:prepare
+          cd spec/dummy
+          bin/rails parallel:setup
+          cd -
       - name: Run tests
         run: |
-          bundle exec rspec
+          bin/parallel_rspec
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v5
         if: matrix.rails == '8.0' && matrix.ruby == '3.4'

Gemfile

@@ -23,6 +23,7 @@ end
 
 group :development, :test do
   gem "execjs", "~> 2.10.0"
+  gem "parallel_tests", "~> 5.5"
   gem "rubocop", require: false
   gem "standard", "~> 1.25", require: false
 

README.md

@@ -336,6 +336,34 @@ $ bundle exec rake
 
 *) This default task executes the database preparations and runs all defined test cases.
 
+### Run specs in parallel
+
+Using https://github.com/grosser/parallel_tests
+
+#### Once before running
+
+```
+bundle exec rake alchemy:spec:prepare
+cd spec/dummy
+bin/rails parallel:setup
+cd -
+```
+
+#### Start a parallel test run
+
+```
+bin/parallel_rspec
+```
+
+#### After adding a new migration
+
+```
+cd spec/dummy
+bin/rails alchemy:install:migrations
+bin/rails parallel:migrate
+cd -
+```
+
 ### Start the dummy app
 
 You can even start the dummy app and use it to manually test your changes with:

bin/parallel_rspec

@@ -0,0 +1,3 @@
+#!/usr/bin/env ruby
+require "bundler/setup"
+load Gem.bin_path("parallel_tests", "parallel_rspec")

spec/dummy/config/database.yml

@@ -1,29 +1,29 @@
 sqlite: &sqlite
   adapter: sqlite3
-  database: db/<%= Rails.env %>.sqlite3
+  database: db/<%= Rails.env %><%= ENV['TEST_ENV_NUMBER'] %>.sqlite3
 
 mysql: &mysql
   adapter: mysql2
   encoding: utf8mb4
   username: <%= ENV['DB_USER'] %>
   password: <%= ENV['DB_PASSWORD'] %>
-  database: alchemy_cms_dummy_<%= Rails.env %>
+  database: alchemy_cms_dummy_<%= Rails.env %><%= ENV['TEST_ENV_NUMBER'] %>
 
 mariadb: &mariadb
   adapter: mysql2
   encoding: utf8mb4
   port: 3307
   username: <%= ENV['DB_USER'] %>
   password: <%= ENV['DB_PASSWORD'] %>
-  database: alchemy_cms_dummy_<%= Rails.env %>
+  database: alchemy_cms_dummy_<%= Rails.env %><%= ENV['TEST_ENV_NUMBER'] %>
 
 postgresql: &postgresql
   adapter: postgresql
   <% if ENV['DB_USER'] %>
   username: <%= ENV['DB_USER'] %>
   password: <%= ENV['DB_PASSWORD'] %>
   <% end %>
-  database: alchemy_cms_dummy_<%= Rails.env %>
+  database: alchemy_cms_dummy_<%= Rails.env %><%= ENV['TEST_ENV_NUMBER'] %>
   min_messages: ERROR
 
 defaults: &defaults

spec/spec_helper.rb

@@ -12,11 +12,19 @@
   add_filter "/lib/generators"
 end
 
+if ENV["TEST_ENV_NUMBER"] # parallel specs
+  SimpleCov.at_exit do
+    result = SimpleCov.result
+    result.format! if ParallelTests.number_of_running_processes <= 1
+  end
+end
+
 require "rspec/core"
 
 RSpec.configure do |config|
   config.raise_errors_for_deprecations!
   config.run_all_when_everything_filtered = true
   config.pattern = "**/*_spec.rb"
   config.filter_run :focus
+  config.silence_filter_announcements = true if ENV["TEST_ENV_NUMBER"]
 end