cask-tests: run in parallel

Library/Homebrew/cask/Gemfile

@@ -16,6 +16,7 @@ group :test do
   gem "minitest", "5.4.1"
   gem "minitest-reporters"
   gem "mocha", "1.1.0", require: false
+  gem "parallel_tests"
   gem "rspec", "~> 3.0.0"
   gem "rspec-its", require: false
   gem "rspec-wait", require: false

Library/Homebrew/cask/Gemfile.lock

@@ -23,6 +23,9 @@ GEM
       ruby-progressbar
     mocha (1.1.0)
       metaclass (~> 0.0.1)
+    parallel (1.9.0)
+    parallel_tests (2.9.0)
+      parallel
     parser (2.3.1.2)
       ast (~> 2.2)
     powerpack (0.1.1)
@@ -80,6 +83,7 @@ DEPENDENCIES
   minitest (= 5.4.1)
   minitest-reporters
   mocha (= 1.1.0)
+  parallel_tests
   pry
   pry-byebug
   rake

Library/Homebrew/cask/Rakefile

@@ -6,40 +6,11 @@ homebrew_repo = `brew --repository`.chomp
 $LOAD_PATH.unshift(File.expand_path("#{homebrew_repo}/Library/Homebrew"))
 $LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))
 
-namespace :test do
-  Rake::TestTask.new(:minitest) do |t|
-    # TODO: setting the --seed here is an ugly temporary hack, to remain only
-    #       until test-suite glitches are fixed.
-    ENV["TESTOPTS"] = "--seed=14830" if ENV["TRAVIS"]
-    t.pattern = "test/**/*_test.rb"
-    t.libs << "test"
-  end
-
-  RSpec::Core::RakeTask.new(:rspec)
-
-  desc "Run tests for minitest and RSpec with coverage"
-  task :coverage do
-    ENV["HOMEBREW_TESTS_COVERAGE"] = "1"
-
-    Rake::Task[:test].invoke
-
-    if ENV["CODECOV_TOKEN"]
-      require "simplecov"
-      require "codecov"
-      formatter = SimpleCov::Formatter::Codecov.new
-      formatter.format(SimpleCov::ResultMerger.merged_result)
-    end
-  end
-end
-
-desc "Run tests for minitest and RSpec"
-task test: ["test:minitest", "test:rspec"]
-
 RuboCop::RakeTask.new(:rubocop) do |t|
   t.options = ["--force-exclusion"]
 end
 
-task default: [:test, :rubocop]
+task default: [:rubocop]
 
 desc "Open a REPL for debugging and experimentation"
 task :console do

Library/Homebrew/cask/cmd/brew-cask-tests.rb

 require "English"
 
+def run_tests(executable, files, args = [])
+  system "bundle", "exec", executable, "--", *args, "--", *files
+end
+
 repo_root = Pathname(__FILE__).realpath.parent.parent
 repo_root.cd do
   ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
@@ -9,12 +13,21 @@ repo_root.cd do
     system "bundle", "install", "--path", "vendor/bundle"
   end
 
-  test_task = "test"
-  %w[rspec minitest coverage].each do |subtask|
-    next unless ARGV.flag?("--#{subtask}")
-    test_task = "test:#{subtask}"
+  rspec = ARGV.flag?("--rspec") || !ARGV.flag?("--minitest")
+  minitest = ARGV.flag?("--minitest") || !ARGV.flag?("--rspec")
+
+  ENV["TESTOPTS"] = "--seed=14830" if ENV["TRAVIS"]
+  ENV["HOMEBREW_TESTS_COVERAGE"] = "1" if ARGV.flag?("--coverage")
+
+  run_tests "parallel_rspec", Dir["spec/**/*_spec.rb"] if rspec
+  run_tests "parallel_test", Dir["test/**/*_test.rb"] if minitest
+
+  if ENV["CODECOV_TOKEN"]
+    require "simplecov"
+    require "codecov"
+    formatter = SimpleCov::Formatter::Codecov.new
+    formatter.format(SimpleCov::ResultMerger.merged_result)
   end
 
-  system "bundle", "exec", "rake", test_task
   Homebrew.failed = !$CHILD_STATUS.success?
 end