Run tests in parallel via parallel_tests

Uses the parallel_tests gem to execute tests in multiple processes
simultaneously on the same machine.

Adds the `--parallel` CLI option that instructs the QA framework
to use the parallel_tests executable.

Tests need access to global state contained in `Runtime::Scenario`
so when `--parallel` is invoked `Runtime::Scenario` is serialized
to an environment variable, which is passed to parallel_tests,
and then deserialized in `spec_helper`.

4 files changed, 70 insertions, 8 deletions

diff --git a/qa/spec/page/logging_spec.rb b/qa/spec/page/logging_spec.rb
index 0f1ed039149..92a4f7b40e6 100644
--- a/qa/spec/page/logging_spec.rb
+++ b/qa/spec/page/logging_spec.rb
@@ -91,26 +91,26 @@ describe QA::Support::Page::Logging do
 
   it 'logs has_element?' do
     expect { subject.has_element?(:element) }
-      .to output(/has_element\? :element \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_element\? :element \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_element? with text' do
     expect { subject.has_element?(:element, text: "some text") }
-      .to output(/has_element\? :element with text \"some text\" \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_element\? :element with text \"some text\" \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_no_element?' do
     allow(page).to receive(:has_no_css?).and_return(true)
 
     expect { subject.has_no_element?(:element) }
-      .to output(/has_no_element\? :element \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_no_element\? :element \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_no_element? with text' do
     allow(page).to receive(:has_no_css?).and_return(true)
 
     expect { subject.has_no_element?(:element, text: "more text") }
-      .to output(/has_no_element\? :element with text \"more text\" \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_no_element\? :element with text \"more text\" \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_text?' do
diff --git a/qa/spec/spec_helper.rb b/qa/spec/spec_helper.rb
index f25dbf3a8ab..21bfd2876a9 100644
--- a/qa/spec/spec_helper.rb
+++ b/qa/spec/spec_helper.rb
@@ -8,6 +8,10 @@ if ENV['CI'] && QA::Runtime::Env.knapsack? && !ENV['NO_KNAPSACK']
   Knapsack::Adapters::RSpecAdapter.bind
 end
 
+QA::Runtime::Browser.configure!
+
+QA::Runtime::Scenario.from_env(QA::Runtime::Env.runtime_scenario_attributes) if QA::Runtime::Env.runtime_scenario_attributes
+
 %w[helpers shared_examples].each do |d|
   Dir[::File.join(__dir__, d, '**', '*.rb')].each { |f| require f }
 end
diff --git a/qa/spec/specs/parallel_runner_spec.rb b/qa/spec/specs/parallel_runner_spec.rb
new file mode 100644
index 00000000000..67d94a1f648
--- /dev/null
+++ b/qa/spec/specs/parallel_runner_spec.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+describe QA::Specs::ParallelRunner do
+  include Helpers::StubENV
+
+  before do
+    allow(QA::Runtime::Scenario).to receive(:attributes).and_return(parallel: true)
+    stub_env('GITLAB_QA_ACCESS_TOKEN', 'skip_token_creation')
+  end
+
+  it 'passes args to parallel_tests' do
+    expect_cli_arguments(['--tag', '~orchestrated', *QA::Specs::Runner::DEFAULT_TEST_PATH_ARGS])
+
+    subject.run(['--tag', '~orchestrated', *QA::Specs::Runner::DEFAULT_TEST_PATH_ARGS])
+  end
+
+  it 'passes a given test path to parallel_tests and adds a separator' do
+    expect_cli_arguments(%w[-- qa/specs/features/foo])
+
+    subject.run(%w[qa/specs/features/foo])
+  end
+
+  it 'passes tags and test paths to parallel_tests and adds a separator' do
+    expect_cli_arguments(%w[--tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+
+    subject.run(%w[--tag smoke qa/specs/features/foo qa/specs/features/bar])
+  end
+
+  it 'passes tags and test paths with separators to parallel_tests' do
+    expect_cli_arguments(%w[-- --tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+
+    subject.run(%w[-- --tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+  end
+
+  it 'passes supported environment variables' do
+    # Test only env vars starting with GITLAB because some of the others
+    # affect how the runner behaves, and we're not concerned with those
+    # behaviors in this test
+    gitlab_env_vars = QA::Runtime::Env::ENV_VARIABLES.reject { |v| !v.start_with?('GITLAB') }
+
+    gitlab_env_vars.each do |k, v|
+      stub_env(k, v)
+    end
+
+    gitlab_env_vars['QA_RUNTIME_SCENARIO_ATTRIBUTES'] = '{"parallel":true}'
+
+    expect_cli_arguments([], gitlab_env_vars)
+
+    subject.run([])
+  end
+
+  def expect_cli_arguments(arguments, env = { 'QA_RUNTIME_SCENARIO_ATTRIBUTES' => '{"parallel":true}' })
+    cmd = "bundle exec parallel_test -t rspec --combine-stderr --serialize-stdout -- #{arguments.join(' ')}"
+    expect(Open3).to receive(:popen2e)
+      .with(hash_including(env), cmd)
+      .and_return(0)
+  end
+end
diff --git a/qa/spec/specs/runner_spec.rb b/qa/spec/specs/runner_spec.rb
index f94145d148e..6c533c6dc7d 100644
--- a/qa/spec/specs/runner_spec.rb
+++ b/qa/spec/specs/runner_spec.rb
@@ -58,11 +58,11 @@ describe QA::Specs::Runner do
       end
     end
 
-    context 'when "-- qa/specs/features/foo" is set as options' do
-      subject { described_class.new.tap { |runner| runner.options = %w[-- qa/specs/features/foo] } }
+    context 'when "--tag smoke" and "qa/specs/features/foo" are set as options' do
+      subject { described_class.new.tap { |runner| runner.options = %w[--tag smoke qa/specs/features/foo] } }
 
-      it 'passes the given tests path and excludes the orchestrated tag' do
-        expect_rspec_runner_arguments(['--tag', '~orchestrated', '--', 'qa/specs/features/foo'])
+      it 'focuses on the given tag and includes the path without excluding the orchestrated tag' do
+        expect_rspec_runner_arguments(['--tag', 'smoke', 'qa/specs/features/foo'])
 
         subject.perform
       end