Add login flow

Adds a Flow module for frequently used sequences of actions

Adds a login flow, including for logging in, performing some actions
and then logging out.

Updates a test as an example of how to use the login flow.

Adds a class method `QA::Resource::User.admin` to provide access
to the admin user's details (include username/password needed to
sign in)

doc/development/testing_guide/end_to_end/flows.md

+# Flows in GitLab QA
+
+Flows are frequently used sequences of actions. They are a higher level
+of abstraction than page objects. Flows can include multiple page objects,
+or any other relevant code.
+
+For example, the sign in flow encapsulates two steps that are included
+in every browser UI test.
+
+```ruby
+# QA::Flow::Login
+
+def sign_in(as: nil)
+  Runtime::Browser.visit(:gitlab, Page::Main::Login)
+  Page::Main::Login.perform { |login| login.sign_in_using_credentials(user: as) }
+end
+
+# When used in a test
+
+it 'performs a test after signing in as the default user' do
+  Flow::Login.sign_in
+
+  # Perform the test
+end
+```
+
+`QA::Flow::Login` provides an even more useful flow, allowing a test to easily switch users.
+
+```ruby
+# QA::Flow::Login
+
+def while_signed_in(as: nil)
+  Page::Main::Menu.perform(&:sign_out_if_signed_in)
+
+  sign_in(as: as)
+
+  yield
+
+  Page::Main::Menu.perform(&:sign_out)
+end
+
+# When used in a test
+
+it 'performs a test as one user and verifies as another' do
+  user1 = Resource::User.fabricate_or_use(Runtime::Env.gitlab_qa_username_1, Runtime::Env.gitlab_qa_password_1)
+  user2 = Resource::User.fabricate_or_use(Runtime::Env.gitlab_qa_username_2, Runtime::Env.gitlab_qa_password_2)
+
+  Flow::Login.while_signed_in(as: user1) do
+    # Perform some setup as user1
+  end
+
+  Flow::Login.sign_in(as: user2)
+
+  # Perform the rest of the test as user2
+end
+```

doc/development/testing_guide/end_to_end/index.md

@@ -131,6 +131,7 @@ Continued reading:
 - [Style Guide](style_guide.md)
 - [Best Practices](best_practices.md)
 - [Testing with feature flags](feature_flags.md)
+- [Flows](flows.md)
 
 ## Where can I ask for help?
 

qa/qa.rb

@@ -9,6 +9,14 @@ require_relative '../lib/gitlab/utils'
 require_relative '../config/initializers/0_inject_enterprise_edition_module'
 
 module QA
+  ##
+  # Helper classes to represent frequently used sequences of actions
+  # (e.g., login)
+  #
+  module Flow
+    autoload :Login, 'qa/flow/login'
+  end
+
   ##
   # GitLab QA runtime classes, mostly singletons.
   #

qa/qa/flow/login.rb

+# frozen_string_literal: true
+
+module QA
+  module Flow
+    module Login
+      module_function
+
+      def while_signed_in(as: nil)
+        Page::Main::Menu.perform(&:sign_out_if_signed_in)
+
+        sign_in(as: as)
+
+        yield
+
+        Page::Main::Menu.perform(&:sign_out)
+      end
+
+      def while_signed_in_as_admin
+        while_signed_in(as: Runtime::User.admin) do
+          yield
+        end
+      end
+
+      def sign_in(as: nil)
+        Runtime::Browser.visit(:gitlab, Page::Main::Login)
+        Page::Main::Login.perform { |login| login.sign_in_using_credentials(user: as) }
+      end
+
+      def sign_in_as_admin
+        sign_in(as: Runtime::User.admin)
+      end
+    end
+  end
+end

qa/qa/runtime/user.rb

@@ -5,6 +5,10 @@ module QA
     module User
       extend self
 
+      def admin
+        Struct.new(:username, :password).new(admin_username, admin_password)
+      end
+
       def default_username
         'root'
       end

qa/qa/specs/features/ee/browser_ui/1_manage/group/group_file_template_spec.rb

@@ -39,7 +39,7 @@ module QA
       ]
 
       before(:all) do
-        login
+        Flow::Login.sign_in_as_admin
 
         @group = Resource::Group.fabricate_via_api! do |group|
           group.path = 'template-group'
@@ -71,16 +71,15 @@ module QA
       end
 
       after(:all) do
-        login unless Page::Main::Menu.perform(&:signed_in?)
-
-        remove_group_file_template_if_set
-
-        Page::Main::Menu.perform(&:sign_out)
+        Flow::Login.while_signed_in_as_admin do
+          remove_group_file_template_if_set
+        end
       end
 
       templates.each do |template|
         it "creates file via custom #{template[:type]} file template" do
-          login
+          Flow::Login.sign_in_as_admin
+
           set_file_template_if_not_already_set
 
           @project.visit!
@@ -101,11 +100,6 @@ module QA
         end
       end
 
-      def login
-        Runtime::Browser.visit(:gitlab, Page::Main::Login)
-        Page::Main::Login.perform(&:sign_in_using_admin_credentials)
-      end
-
       def set_file_template_if_not_already_set
         api_client = Runtime::API::Client.new(:gitlab)
         response = get Runtime::API::Request.new(api_client, "/groups/#{@group.id}").url